Aeroworks Edge 540T ARF
Drop me an email and let me know if you find this review interesting/helpful.
1/26/2002 - FLIGHT AND CONSTRUCTION UPDATE - CLICK HERE FOR DETAILS
FIRST FLIGHT FINALLY OCCURS!! CLICK HERE FOR REVIEW
A new GALLERY section has been added showcasing other builders of the Aerworks Edge 540T ARF.
If you're thinking about a radical covering scheme for a 540, check out these PICTURES of Pip Borman's Edge 540. Pics provided by Glenn Orchard from Australia.
Update Index - Click on each entry to jump directly to that section.
Welcome to the Aeroworks 33% Edge 540T ARF review. This will be a "start to finish" review that will continually be updated during the "assembly" process. I say "assembly" because this is an "almost ready to fly" (ARF) kit. In my opinion ARF is really a misnomer. Most ARF planes require some amount of assembly before being anywhere near "ready to fly". This will be no exception.
During the review I will cover various elements ranging from how the kit is shipped to first (and probably subsequent flights). You will have to check back regularly to see how I am progressing. Given that I have a full-time job (yes, I have to pay for these planes somehow....) and that it is currently 100 degrees F in Texas and I have to build in my un-air-conditioned garage, it may take a while to complete this project.
So, why did I go with the ARF instead of the builder's kit or pre-built kit from Aeroworks? Well, first it was building time. I just don't have the luxury of starting from scratch. Secondly was price. I seriously considered the "deluxe pre-built" kit from Aeroworks, but at $1,795.00 (plus $50.00 for the two-servo wing option), it was a little more than I wanted to invest, especially considering that I wanted to invest in a Desert Aircraft DA100 for the power plant and JR DS8411 digital servos all-around. So at $995.00 (introductory, pre-order price), I thought the ARF would be a good compromise. Finally, the Aeroworks quality was another determining factor. I have seen several Aeroworks kits, and have always been impressed with them. Standing behind this quality is a great staff at Aeroworks - Rocco, Kevin, Jeff, and Sharon.
So, let's get started.... Throughout the review I will refer to "hits" and "misses". No rocket science here - I blatantly stole this idea from all other reviewers before me. There will be a running hits and misses list at the end of this review. You can jump to it by clicking HERE. During this process I will also be communicating my findings to the gang at Aeroworks. In the event they respond to any issues or questions I will include their feedback in the appropriate section.
Click HERE for a complete description of the plane at the Aeroworks site - no need in repeating the obvious.
Ordering
Aeroworks announced the Edge 540T ARF in early 2001. I placed my order on March 3, 2001 and received the plane on July 27, 2001. Why so long? Well, actually they didn't start shipping until sometime in June, and I apparently was fairly far down on the list - even with a March order. Compounding this issue, I think I confused Rocco and Kevin when I initially stated that I might consider switching to the pre-built kit based on when the ARFs began shipping. This may have caused my order to be placed aside. I called Rocco on July 25 (Wednesday) and he said he would get me a plane shipped that week. Was I surprised when I got when I got home on July 27 (Friday) and found three large boxes sitting in the living room! Way to go Aeroworks - customer service!
Shipping
As mentioned, the plane was shipped in three large boxes. These were actually shipping boxes that contained the boxes that contained the plane. So, a little double-walled strength to ensure safe transit. Another nice touch.
The fuselage, tail feathers, landing gear, wing tubes, some miscellaneous balsa, and the plywood for the engine box came in one large box. The cowl, wheel pants, and canopy came in the second box. Finally, the wings halves and decals came in the third box. All components were wrapped in plastic and packed with shipping paper. The landing gear was wrapped in foam. The cowl was in a plastic bag and then wrapped in bubble wrap. One strange thing here. The plastic bag seems to leave a fine haze on the cowl. This is actually mentioned in the documentation. The recommended solution is to use fine rubbing or polishing compound. Seems like this could possibly have been solved by wrapping the cowl in paper or some other material.
Other than that one issue the rest of the components arrived in good condition. There was a very minor amount of hanger rash on the fuselage, but nothing that a quick once over with a covering iron wouldn't cure.
The kit comes with NO hardware (other than the wing and horizontal stab tubes). You can buy a complete hardware kit from Aeroworks, but I chose to be one of those people who likes to pick and choose their own hardware (and make 47 trips to the hobby shop......!). The Assembly Manual includes a complete list of the hardware that they suggest for the plane so you can use that as a starting point.
There was no parts list in the box, so you have to assume that you've gotten everything you were supposed to receive. But how would you know......? An annoyance, but not a show-stopper since I have no reason to believe that the Aeroworks team wouldn't correct any problems with misplaced or damaged materials.
One other thing before we get to the construction. Aeroworks clearly states that they charge a 15% restocking fee for any returned items - no matter what the reason. The customer is also responsible for all shipping costs. Make sure you have decided on the plane you want before you order!
The Instruction Manual
The instruction manual consists of three parts - a 13 page "Assembly Manual", a 5 page "Aeroworks Accessories" manual, and 1 sheet of color photographs of different stages of the building process. I read through the Assembly manual and found it to be quite brief. However, one would assume that the person assembling this 33% plane has some idea of what they are doing since (1) they must know how to fly fairly well, (2) they have probably built planes in the past, and (3) they have just spent a lot of money based on the fact that they think they are good at (1) and (2). Still, a little extra "meat" in the instructions would have been appreciated.
Another thing that many of you know about me is that I am somewhat "anal retentive" about published materials. As the editor of the club newsletter for 3 years I was always worried about putting something to print that contained typos, bad grammar, erroneous information, etc. The instruction manual has a few typos and grammar problems, but nothing serious. I guess we should want the Aeroworks team to know more about designing and building quality airplanes than writing manuals...... Still, Microsoft Word (TM) spellcheck and grammar check works pretty well.....
The one sheet of color photographs is nice to have, but doesn't add a lot of value. Most of the photographs show things that most experienced builders would already know. Click HERE to see a copy of the color photograph sheet. What I would have really liked to have seen is a picture that illustrated step 1 in the Fuse Assembly section - "Locate 3/8" x 3/8" balsa and cut fuse cross braces to fit between longerons and to the rear of former F2, F3, F4." Well, I'm pretty sure I know what they are telling me to do, but a picture or diagram would provide clarity.
The Aeroworks Accessories manual is simply a listing of additional items (wing bags, decals, dashboard panels, etc.) that you can order to enhance your plane. The same information can be found on the Aeroworks website.
The Fuselage (7/28/2001) -- (Back to Top)
The first thing that you notice is that this is a big plane! Well, it is 33%.....! The Edge 540T has quite a "tall" fuselage as compared to other planes. When you look at the fuselage by itself it looks somewhat out of proportion. However, when you add the tail feathers, canopy, and cowl, everything comes back into perspective.
My main concern when I first thought about this plane was the quality of materials - especially the light plywood. Rocco assured me that they were holding the line on quality control and that while it wouldn't be what you could go to your local hobby shop and hand pick out of the rack, it would be good quality. I was pleasantly surprised upon first inspection. All the light ply seemed to be fairly dense and did not contain an excessive amount of discolored or soft wood. Overall - good quality for the price.
The next concern was the glue joints. I spoke at length with Rocco about this. He assured me that they were suing aliphatic glue and not hot glue. In my opinion they are using a mixture of the two. I'm no glue expert, but some of the glue appears to be more of a "hot glue" than what I normally think of as aliphatic. You can judge for yourself in the photos below. However, all the joints appear to be tight.
For the most part everything looks straight and true -with two exceptions. Former F4 is warped. I don't think the former is actually warped - I just think it was not installed correctly and ended up looking to be warped. I toyed with the idea of trying to heat the glue joints loose and straightening it, but it appears to be sufficiently glued and seems to have to effect on the alignment of the fuselage. So for now it stays warped.
The longerons (stringers) between formers F3 and F4 are significantly bowed inward. Now I'm not sure if this is a problem or a "feature". One thing about this plane is that the covering is stretched really tightly. I think that these stringers are simply bowed in because the covering is pulling them in. I will see if Aeroworks has a response here. Once again, there seem to be no fuselage alignment issues here, but this is probably an area that I will address. The reason I intend to fix this problem (feature) is that I will be inside the bottom of the fuselage anyway, so I might as well fix the problem. I plan to add smoke to this beast, and there is no room under the cockpit for a smoke tank. I plan to cut away the covering on the bottom of the fuse to install a 32 oz smoke tank under the platform that spans the fuselage under the cockpit area. Sure hope I can find the same color Ultracote that they used on the plane.......
Speaking of Ultracote, they did a really nice job of covering the plane. Nice and tight for the most part. The Assembly Manual indicates that you should iron out any wrinkles before starting assembly. Of course the real test is the "garage test". Here in Texas in July it gets pretty hot. In fact, as I am writing this a 11:00 PM it is still almost 90 degrees F outside. As I expected, the old Ultracote began to sag a bit in the heat, but nothing a few strokes from the iron shouldn't cure. All the seams appear nice and tight and the stripes a very well done (see pics). Overall a very good job.
Fuselage access should be easy. Lots of room in which to work. Engine mounting should be fairly simple. Oh, this brings me to one point. The instructions call for 2-3 degrees of right thrust and 0 degrees of down thrust in the engine. All pilots have preferences about this - some preferring to incorporate the right/down thrust, others not. Well, Aeroworks pretty much forces you to incorporate the 2-3 degrees of right thrust since the nose of the cowl is offset by the same 2-3 degrees. Either you incorporate 2-3 degrees right thrust on you have a really strange looking fit between cowl and spinner..... Would have been nice to have a choice (but once again I must remind myself - it's an ARF!!!!!).
The landing gear plate looks to be fairly substantial. I will probably add a couple of pieces of tri-stock just for grins. The tail feathers mount points also look to be solid and well constructed. I think there will be room to include a wing tube section in the tail area to add lead weight if desired. More on this later.
The rest of the fuselage story will be told in the pictures below. Click on the thumbnails to view a larger image.
CLICK HERE FOR PICTURES -- (Back to Top)
More Fuselage (7/29/2001) -- (Back to Top)
Scroll down to pictures to see important clarification on Step B.4.
Today was a busy day on the fuselage. I followed the steps 1 through 4 in the Assembly Manual, Section B - Fuse Assembly. Steps 1 and 2 were pretty easy - simply gluing the 3/8" stock to the top/back of formers F2, F3, F4. This step firmed them up very nicely. See pictures below. I also added some 1/4" tri-stock in front of F2-F4, just for some extra support. Probably not needed, but gave me a good feeling anyway.
Step 3 was simple, but tedious. This is where really sharp #11 hobby blades come in handy. Even with the sharpest blades, the process of cutting out circles seems to be hard for me. Anyway, got the job of cutting the wing and stab tubes and anti-rotation cutouts done. One thing I discovered - there is no cutout in the fuselage for the aileron servo leads for the wings! So back to the Assembly Manual to find out what is going on. There is a special note about this on Step C.10. The aileron leads exit right through a lightening hole in the fuse. The instructions recommend "filling" the lightening hole with 1/8" light ply to "give the covering something to stick to". Seems like a little planning/engineering here could have produced a much better solution.
Since I am planning to use a pull-pull I didn't cut out the servo mounting openings in the tail section.
I had to read Step 4 several times. Here it is: "Using 3/8" x 3/8" balsa cut to fit between former F4 and F5 and to the bottom of the top fuse longeron and to the top of the bottom fuse longeron. If using Ca, to glue in bracing be careful not to get any CA glue on the foam turtle deck. The bracing will add extra strength to the fuse at this location." OK, read it again, and again. Actually, what I think is suppose to happen here is the installation of a diagonal brace between the longerons between F4 and F5. Anyway, that's what I did. See pics and more details below.
As mentioned earlier, I opened the bottom of the fuselage from front to back, for three reasons: (1) to install the smoke tank in the belly; (2) to investigate the mysterious bowed longerons (stringers) between F3 and F4; and (3), while I was already cutting covering off I might as well look at the rest of fuselage.
As you can see from the pictures below, the fuselage formers, longerons, stringers, etc., look really nice. I was very pleased with the construction (other than the bowed stringers). Everything was straight and true and looked very solidly attached. The tail section looked well constructed and looked like it will work well with my desire to install a phenolic tube to accept lead-filled wing tube sections for balancing purposes.
As long as I was doing "surgery" I figured I might as well do some cosmetic surgery. I added cap strips to the bottoms of all the formers. There is about a 1/8' gap between the bottom of the formers and the bottom edge of the bottom stringer. I figured this would make the covering look a little better. Okay, I know - more weight. Well, what's a little trade off. I figured I added maybe 1/50th of an ounce...... So far, with all the extra tri-stock and stuff I figure I have added maybe 2-3 ounces.
Now, on to the bowed stringers. This was not good. As you can see from the pics below, the stringer between F3 and F4 was apparently jammed into the F3 and F4 former slots (cutouts) that accept the stringers. The wood around F3 was crushed, and was compressed around F4. I don't know if the stringer was too long, or what, but when it was forced in it also bowed inwards. So, what to do - call Aeroworks and complain, or fix it myself. After some careful study, I decided that I could fix it. I made some 1/4" balsa braces that were keyed to fit around the stringer. I made a total of 4 - two for each side of F3 and two for each side of F4. I glued these braces in place, ensuring that I had good glue coverage in the keyed slot around the stringer. When the glue dried the stringer appeared nice and tight with no play. Now the next question - do I leave the stringers bowed, or do I try to straighten them. Since this area is under the wing, it wouldn't really show, but I just didn't like the way it looked. I made a brace between the stringers to force them back into alignment. I cut lightening holes in the brace and CA-glued it in place. This straightened out the stringers fairly well. When I inserted the brace the covering was wrinkled on both sides. A quick hit with the heat gun and the wrinkles disappeared. The brace should give a little extra strength - especially when picking up the fuselage. So - happy camper with my fix.
I added a section of 3/4" tri stock behind F2 just for grins. Probably not needed, but with the engine box attaching through this former I thought it would be a good idea.
Next was the installation of the smoke tank. Actually I haven't installed it yet. I debated whether to install it and simply recover the bottom of the fuselage, or build an access hatch. Since I usually redo things 2 or 3 times, I figured an access hatch would be easier than recovering the bottom of the fuselage every time I needed to get to the smoke tank. I built a ledge between F2 and F3 for this purpose. I think the pictures are self explanatory.
At this point in the assembly I am still very positive on this plane. Other than the bowed/crushed stringer, everything looks really good inside the fuselage. Next steps will be to mount the tanks. I will then probably mount the landing gear and tail wheel so I can set the bird up on its feet. I will then mount the engine, tail feathers, and wings. I will save the canopy for last - I hate canopies...... Enjoy the pics below!
CLICK HERE FOR PICTURES -- (Back to Top)
The Wheel pants (7/30/2001) -- (Back to Top)
Tonight was a short work session due to the heat. Another 100 degree day in Dallas, so I chose a fairly simple task - mounting the wheel pants. The wheel pants are made of fiberglass and are of EXCELLENT quality. Good strong seams, no pin holes, and a very good paint job. No wheel are supplied with the kit, so I chose to use 4" (recommended size) Kavan cross tread wheels. These are very lightweight, but should hold up very well. The landing gear felt a little "springy". I am used to using fairly stiff aluminum gears on big birds, so this may present a challenge on those windy days here in Texas - especially since I am not known as "Mr. Smooth" when it comes to landing (OK, all you RRCC guys can quit snickering now....).
Each wheel pant has two light plywood squares glued inside - one on each side. I'm not sure if this is for strength, or Aeroworks figured that you might not know which way to mount the pants... The light plywood squares seem to be glued in solidly. The landing gear contains a hole for mounting the axle, and then two smaller holes right above the axle hole. These are for screws which go through the landing gear into the wheel pants (into the light plywood). I am not a fan of this method of installation, so I chose to use Sig Wheel Pant Mounts (part number SIGSH720). I used Dubro 3/16" by 2" Spring Steel Axle Shafts (part number 249) for the axles, along with Dubro 3/16" Plated Brass Dura-Collars (part number 141) to hold the wheels on.
The opening for the wheels was just big enough to insert the 4" wheels, so I knew I would need some extra space when the wheel pant mounts were used. I got out the trusty Dremel with a sanding drum attachment and expanded the opening about 1/8" all around. See the pics below for a before and after comparison. A tip on using the Dremel to do this - lay down a strip of masking tape to provide a reference point (instead of drawing a line). You can nibble right up to the tape and make a very straight line. A little sanding with a piece of 80 grit sandpaper stuck to a tongue depressor and the edges are nice and smooth.
After a few measurements, a 3/16" hole was drilled in the side of the wheel pant. The wheel pant mount holes were then drilled and the mount screwed in place. The screws were just long enough to go through the wheel pant, light plywood, and the mount itself. When I inserted the wheel the shaft hub was a little bit too tall causing the wheel to be off-center in the wheel pant opening. I used a 1/2" drill in the drill presss and shortened the hub about 3/32". See pics below.
I placed a washer on the axle, then inserted it into the wheel pant through the wheel pant mount. Then another washer, the wheel, and then the 3/16" collar. This last part is tricky as you know, since there is not much room to maneuver the collar into place. A pair of bent-nose needle nose pliers works great for this task. Aligned everything and tightened the wheel pant mount set screw. The end result looks really nice - see for yourself!
CLICK HERE FOR PICTURES -- (Back to Top)
Aileron Servo Lead Cutouts (7/31/2001) -- (Back to Top)
This was a fairly simple, but in my opinion, an unnecessary step. As mentioned earlier, there are no aileron servo lead cutouts (access holes) in the fuselage. Why? Because the servo lead tunnels (and exit holes) in the root cord of the wing line up with a lightening cutout in the fuselage. Therefore, there is nothing in which to cut an exit hole in the fuselage! You can't simply cut slits in the Ultracote and run the servo leads through them (well, I guess you could, but this would be disastrous). So, according to step C.10 you must fill the lightening hole with 1/8" light ply through which to drill (cut out) the servo lead access hole and to give the Ultracote something to stick to. I hope Aeroworks will make an engineering mod soon and solve this problem, or at least throw the lightening hole cutouts in the box instead of the trash. This is assembly time that could be well spent doing something else.
Anyway, the biggest task was getting a 1/8" light ply plug to fill the lightening hole. After some measuring and trial fitting I had some plugs that fit fairly snuggly. I placed these in the lightening holes and then glued a section of 1/8" balsa over the plug and surrounding fuse area to hold everything in place. I then measured the distance from the back anti-rotation pin to the middle of the servo lead access hole in each wing root cord. I laid down a strip of 1" masking tape between the front and back anti-rotation pin holes on the fuse, drew a center line between the two, and then marked off the distance from the back anti-rotation pin hole to where the servo lead access hole should be on the fuse. I used a 3/8" piece of brass tubing to scribe a circle where the access hole should be. I then trimmed out this area with a #1l hobby knife and the drilled the hole with my Dremel. A quick hit with the covering iron to seal the Ultracote and I now have servo lead access holes.........
CLICK HERE FOR PICTURES -- (Back to Top)
Response from Aeroworks on glue (8/1/2001) -- (Back to Top)
Kevin from Aeroworks responded to my question about the type of glue. Here is his response from his email:
"The glue is all white glue, they do not have a glue gun in the place. We made sure of that."
This is good news! Thanks Kevin!
Mounting the land gear (8/1/2001) -- (Back to Top)
Tonight was another short night due to the heat. Since I am waiting on the servo arms from Nelson Hobby, I decided not to tackle any of the control surface activities yet. Therefore I thought that mounting the landing gear should be a fairly easy task, and it was. The instructions (Step F.5 and F.6) were clear and easy to follow. I started by laying down several strips of masking tape on which I could mark the reference points. I measured 1 3/4" from the front edge of the gear mounting plate and drew a reference line (black). I then drew another line (red) 10mm further back. This is the distance from the leading edge of the landing gear to the center of the front mounting holes. The mounting holes are 140mm from center to center. I then measured the width of the fuselage at the red line, which was 204mm. Subtracting the distance between the front mounting holes left 64mm, which I divided by 2 to get the distance from each edge - 32mm. I then marked these points on the red line and this gave me exact centering for the landing gear.
I followed the instructions and used 10-32 bolts and blind nuts. I drilled the holes using a 7/32" bit. I placed the bolts through the landing gear holes and through the landing gear plates. I threaded then blind nuts on the bolts and the tightened them down securely. After inspecting everything to make the landing gear was straight and centered, I marked the rear landing gear mounting holes using the landing gear holes as the guide. I repeated the drilling/mounting process for the rear holes.
Call me "Mr. Overkill", but I decided to all 1/2" tri-stock along the top edge of the landing gear plate. I have flown big birds before, and know that a "less than glass smooth" landing can put quite a stress on the gear and mounts. I figured the approximately 1/16th ounce in weight of balsa and epoxy was a small price to pay for a little extra sense of security.
CLICK HERE FOR PICTURES -- (Back to Top)
Building the Engine Box (8/5/2001) -- (Back to Top)
OK- For those of you have been following this review this is "Round Two" of the engine box. . I rebuilt the engine box according to "specs". I made a new firewall by gluing 3 sheets of 5-ply 1/8" plywood together to make a 15-ply firewall. That should be sturdy enough. Now - back to the engine box.
This is Step E - Engine Box Assembly. If you have built large scale airplanes before then this should be a fairly easy step. NOTE: The firewall is designed with a 2-3 right thrust offset built in. However, the instructions DO NOT mention this in any form or fashion in this section! This is why one of the light plywood sides is slight longer (approximately 5/16") than the other. As viewed from the front, the shorter one goes on the left and the longer one on the right. The light ply bottom has an approximately 2-3 degree offset built into the from to match the offset of the firewall. The sides of the firewall have an approximately 2-3 degree bevel on each side. When you glue all these pieces together correctly the firewall should have the correct offset. This is crucial since the nose of the cowl has an offset built in.
The building materials include two 1/8" light ply sheets approximately 3 7/8" wide. One is approximately 12" long and the other is approximately 12 5/16" long. Each sheet is notched so it will fit in the opening in former F2. The sheets fit through former F1 and into former F2. The fit was nice and snug. In order to determine how long to make the engine box in front of the firewall the instructions suggest to mount the cowl about 3/4 inch onto the fuse and then measure the distance from the F1 to the front of the cowl at the nose. This is easy if you have about 6 hands..... After using some masking tape to somewhat hold things in place and was able to determine the length to be about 13 1/4". Seems like Aeroworks should know this if all their kits are made fairly consistently. Remember that the nose of the cowl has the offset built in, so measure in the middle of the opening.
The instructions then tell you to measure the engine length (this needs to be from back of engine mounting bracket to leading edge of prop backplate. In the case of the DA 100 this is 6.5139 inches (according to DA's documentation). I rounded to 6.5 inches...! The instructions then indicate to subtract this length from the previously determined length to get the length of the engine box. In this case that leaves 6 3/4". They then suggest to shorten this by 1/2" so you can use spacers to move the engine back and forth for a good fit - in this case leaving 6 1/4". In my case, the sides stuck out only 5 7/8" beyond F1, so this was not a problem.
The firewall supplied with the kit is 3/8" 8-ply heavy duty plywood with the sides beveled approximately 2-3 degrees. The instructions call for mounting the bottom of he firewall flush with the bottom of the sides. I deviated from this slightly, moving the firewall up 1/8". This will allow me to insert the bottom of the engine box between the sides and then under the bottom of the firewall. I plan extend the bottom of the box through F1 back to F2 (see pics). I think this will be sturdier. The instructions call for cutting the light ply bottom to fit under the sides and the firewall, and then butting up next to F1. Probably ok, but I thought my method was stronger (of course, added a tad of extra weight, but I would rather have the extra weight as opposed to the engine coming off in flight!). Since the engine thrust line is measured from the top of the sides (not the top of the firewall), moving the firewall up slightly has no affect, and it allows you to pin the bottom plate to the firewall using hardwood dowels.
1/8" hardwood dowels are supplied to pin the firewall. The instructions call for using 3/8" balsa tri-stock for extra reinforcement of all glue joints, and recommend using 3/8" spruce tri-stock behind the firewall. A piece of 3/8" balsa tri-stock is supplied with the kit, but not the spruce tri-stock. One thing you will have to keep in mind is that since the firewall is offset by 2-3 degrees, the angles between the firewall and the engine box sides are no longer 90 degrees. One will be approximately 92-93 degrees and the other will be approximately 87-88 degrees. In order to get a tight fit you will have to sand down one side of the spruce stock to match the angle between the side and the firewall. A drum or flatbed sander makes this a whole lot easier. Good luck if you don't have one!
The instructions suggest an optional 1/4" light ply top for the box. The 1/4" ply is not supplied with the kit. The instructions call for simply butting the 1/4" top plate up against F1, with the top plate resting on the top of the sides. I am not a fan of simply butting things up against each other. So, I once again deviated from the instructions (even though there are no real instructions here). I made the top plate to fit between the sides, extending the top plate through F1 about 1 1/2 inches. This will allow me to place the tri-stock on the back of F1, as opposed to the front. I think this will be a little stronger. This will also add a little more gluing area to the top plate. I cut away most of the area of the top plate that fit behind F1 and then added lightening holes (see pics). You can't really tell from the pictures supplied by Aeroworks, but I don't think they extended the top plate to the firewall. As you can see from my pics, I did. I am also not a fan of three-sided engine boxes. I had to cutout part of the front of the top plate to accommodate the engine mounting bolts, washers and nuts, but still had enough to glue the top plate to the firewall and add some hardwood tri-stock. Make sure you know where the top engine bolts will be before you build and glue in your top plate. The last thing you want is your engine mounting bolts going right into your top plate.....! I drilled lightening holes in the front of the top plate to reduce as much weight as possible. Yes, I know - I probably overbuild, but I would rather overbuild in some cases that put $3,800 worth of plane, engine, servos, etc., into the hard Texas dirt because the firewall came loose.
I test mounted the engine to see how things lined up. One thing to note - you have to offset the engine 3/8" to the right (as viewed from the front) from the vertical center line so the prop shaft (crankshaft) will center through the nose of the cowl. I quickly found out that I must have had closer to 3 degrees offset because the crankshaft was not centered. So, I added a 1/8" spacer to the left engine mount (as viewed from the front) and this brought me back close to 2 degrees and solved the problem. I then tried to test fit the cowl. The DA 100 will not fit in the cowl unless you cut openings for the spark plug wires. This is exacerbated by the offset on the right side (once, again as viewed from the front). The DA 100 probably would not have fit even if the engine was mounted without an offset, or it would have been so close that vibration would have been an issue. So much for looks!
So, I think I now have one sturdy engine box. Probably stronger than necessary, but what the heck.
CLICK HERE FOR PICTURES -- (Back to Top)
Mounting the Engine (8/6/2001) -- (Back to Top)
There is no official step for this in the Assembly Manual. Aeroworks recommends that you "install engine per manufactures [sic] recommendations." Step I - Cowl Installation states that the engine thrust line is 1 3/8" down from the top for the fuse box sides. I'm not sure if they really mean fuse box or engine box, but since the top of the fuselage sides and the engine box sides line up, it doesn't really matter. I will check with Aeroworks for clarification. Step I also indicates that you must mount the engine 3/8" to the left (from the pilot's view) to compensate for the offset for the right thrust. I marked both the engine thrust line and then the vertical center line of the firewall. I then measured 3/8" from center from the vertical center line per the instructions.
Mounting the engine was fairly simple. I made a mounting plate template for the DA 100 from some 1/8" scrap plastic. I located the vertical and horizontal center lines and the lined them up with the vertical and horizontal and vertical lines on the firewall and marked the engine bolt holes. I drilled 1/4" holes and then mounted the engine with 1/4" x 2" socket head cap screws, 1" washers, and 1/4" nylon lock nuts.
I was very lucky in that the throttle arm linkage point is just ever so slightly below the bottom of the engine box. This will allow me to attach the throttle servo linkage right under engine box. Since there is a lot of room under the bottom of the fuselage compartment between F1 and F2, I plan to mount the throttle upside down under this compartment. This will give me a very direct line of sight for the throttle servo linkage.
That's it for today. Off to work. Tonight I will mount the throttle servo and the ignition. I will also add pics of the cowl with the holes cut to accommodate the sparkplug wires.
CLICK HERE FOR PICTURES -- (Back to Top)
Throttle Servo and Linkage (8/8/2001) -- (Back to Top)
Luckily the throttle linkage on the DA 100 lined up very nicely with the bottom of the engine box, so this provide a good place to run and secure the throttle linkage. I looked at several places to mount the throttle servo - inside the fuselage platform, in the fuel tank compartment, between the fuselage platform and the landing gear block, etc. I chose the latter because it gave me the best line of sight to the throttle arm on the DA 100. I have also decided to mount both the fuel tank and the smoke tank under the fuselage platform, so this gave me some extra space up top. Otherwise there would not have been space to mount the throttle servo in this area.
I marked a line from the throttle arm back to F1 (see picture above). I then drilled a 5/16" inch hole right at the bottom of the engine box through F1. This provided the entry point into the space between the fuselage platform and the landing gear block. I cut a servo hole in the fuselage platform as close to F2 as possible, while still allowing space for the servo arm arc movement. I did this to allow as much space between the front of the servo and the firewall to place the ignition.
I inserted the Nyrod tube through the hole in F1, and then inserted the Nyrod linkage. I attached the Nyrod linkage to the servo arm and then attached the arm to the servo. I then mounted the servo upside down in the hole I cut for the servo using 3/4" 2-56 socket head screws and nylon lock nuts.
This provided a direct line of sight for the servo linkage to the throttle arm, with absolutely no binding. I attached the servo linkage to the throttle arm with a 2-56 swivel ball link. I then made and glued some balsa stops to hold the Nyrod tube to the bottom of the engine box.
Don't try this method unless (1) you are patient, (2) you have long skinny fingers, (3) you don't mind skinned knuckles, and (4) you have a good pair of long hemostats!
CLICK HERE FOR PICTURES -- (Back to Top)
Cowl Fitting (8/8/2001) -- (Back to Top)
The cowl does not appear that it will be much
trouble to mount (if you have mounted cowls before...). The DA 100 is
unfortunately slightly wider than the cowl. This would be the case even if
the engine had no offset. However, the offset requires that you mount the
engine 3/8" off the of vertical centerline, so this this makes the right
cylinder and spark plug (as viewed from the front) stick out even further.
Therefore holes have to be cut......
There are as many ways to determine where to cut these holes as there are RC
modelers. I took a fairly simple approach. I placed the cowl
as close as possible to where the final fit will be. I then simply applied
pressure to the side of the cowl. The spark plug makes a small protrusion
(pimple) on the side. I marked this spot with a pencil, then took the cowl
off and cut a small hole with my Dremel tool. Then remounted the cowl to
make sure I was in the general vicinity. Removed the cowl, cut a little
more. Remounted and checked. Removed and cut. Repeat, repeat, repeat
- well, you know the drill. Then did the same for the other side.
The sparkplug on the right (as viewed from front) sticks out quite a bit, so a
fairly large hole was required. I tried to make it as snug as possible,
while ensuring that I left enough space to accommodate vibration. All in
all, doesn't look too bad, but would have preferred no holes. I have seen
these planes with BMEs, and the sparkplugs stick out the top......
CLICK HERE FOR PICTURES -- (Back to Top)
Thrust Line Clarification (8/8/2001) -- (Back to Top)
I received an email response from Aeroworks on the question about where to measure the thrust line. The instructions in Step I indicate to measure 1 3/8" down from the top of the "fuselage sides". I asked AW if they meant fuselage sides or engine box sides. They indicated that it is from the top of the engine box sides. This is not really an issue since the top of the fuselage sides (plywood sides) and the top of the engine box sides are the same. I just wanted to make sure for the purpose of clarity. Thanks for responding AW!
Wing Retainer System (8/15/2001) -- (Back to Top)
I chose a different method for the wing retainer bolts. This is due to a couple of reasons. First, I don't like having the wing tube permanently bolted into one wing panel. This makes transporting the wing somewhat unwieldly. Secondly, another builder (Leroy Brandt) of this plane shared his experiences with me in this area - he felt that the hardwood used in the wings through which the retainer bolts are inserted is somewhat soft.
The method I chose was to basically insert 1" hardwood plugs into the wing at the root. These are about 1 3/4" long and have 1/4x20 threaded inserts screwed into them. You have to be very careful when screwing in the inserts, or you will split the plugs. The method that I found works best is to drill the hole for the insert only as deep as the insert itself. You can then go back later and finish drilling the hole from the other end of the plug. I used a little dab of J&B Weld on the threaded inserts just for grins. Each plug with the threaded insert weighed about .5 ounce.
I used a 15/16" hole saw to drill the holes in the wings. You need to use a hole saw that is 1/16" smaller than your plug to get a good snug fit. I chose the spa-ce between the wing tube and F3 to insert the plugs. I figured this was a fairly big target area and the fuselage should be strong here. I screwed a 3" nylon bolt into the threaded insert and then put a good coat of 30 minute epoxy in the hole and on the plug. The nylon bolt allows you to move the plug up and down to ensure it is flush with the root rib.
After the glue dried I screwed in a 1/4" nylon bolt which I had sharpened to a point on one end. I then slid the wing in place on the wing tube and aligned the anti-rotation pins. I then pushed the wing firmly against the fuselage. The point on the nylon bolt made an indention exactly where the hole will need to be drilled in the fuselage. I then drilled a 1/4" hole in the fuselage and backed it with a 1" square of 1/8" plywood. I will use 1/4x20 socket head cap screws to secure the wings to the fuselage.
CLICK HERE FOR PICTURES -- (Back to Top)
Servo Matching (8/18/2001) -- (Back to Top)
Since the ailerons call for dual servos, and I plan to use two ganged servos on the rudder, I spent some time doing some "servo matching". Basically, this is a process of determining which combination of servos and servo arms will work best when paired together - that is, which servos and arms will align mostly closely and cause the least amount of resistance (fighting) between each pair. To do this, I built a tool that measures the "center" point of each servo as well as the sweep. Since the splines in the servo arms and the servo gear a slightly different, each combination of servo and arm will usually produce a different center point. The sweep should usually be the same and shouldn't be a concern, but if you have a servo that has a total sweep that is substantially different from its partner, then this could cause resistance. The net result is that the fighting between the servo pairs significantly reduces battery life and ultimately the life of each servo.
The "tool" consists of a rectangular piece of 3/4" plywood which is about 18"x24". A notch is cut in one side to accept a servo. The center point of the pivot is then located and a line is drawn on the board 90 degrees to the servo. This would be the desired center point for a servo and a servo arm. But, unfortunately, it doesn't work that way. So, you basically draw a "protractor" on the board, marking of 5 degree intervals between 70 degrees and 120 degrees. This covers the span of normal servo/servo arm variations. Between 0 and 70, and 120 and 180 degrees, 10 degree intervals are fine.
A reference pointer is made from a 1/8"x1/4" piece of spruce. It is important that this pointer be straight and it should have a point at the sweep end. It is also important that the pointer be attached to each servo arm in the same exact way to ensure consistency of measurement. I am using Nelson servo arms and these work quite well for this since you can slide the pointer between the two halves of the arms and secure them using 4-40 socket head cap screws.
Each servo and servo arm combination is then measured by attaching the servo to a receiver and battery. The distance left and right of 90 degrees is then recorded, as well as the total sweep (full left aileron to full right aileron). This is quite a tedious task, but will be worth the effort. It took me about 2 hours to measure 8 servos and 7 servo arm combinations. I am still waiting on one more servo arm set from Nelson Hobbies, so I will measure it as soon as I get it. When all servo/servo arm combinations are measured, I will then start matching the closest pairs. If I can get pairs that are within 1-2 degrees then life will be fairly good. If not, then I will start rebuilding the servo arms (Nelson servo arms using standard servo wheels as the hub) and keep trying until I get as close as possible. Obviously, the two independent elevator servos will not be an issue.
In addition to the pictures, I have attached a copy of the current Excel spreadsheet I used to capture the results. The Arm 8 numbers are simply "plugged" at this point.
CLICK HERE FOR PICTURES -- (Back to Top)
Tail Section Assembly (8/18/2001) -- (Back to Top)
I began the tail section assembly tonight. This appears to be fairly straight forward. The cutout section in the fuselage that receives the fin is nice and square and looks solid. The instructions are very brief here, simply stating to trim the covering from the top and back of the tail section to provide a good gluing surface. I followed the instructions and glued the fin to the fuselage using 30 minute epoxy and then taped everything in place. The only thing that I think could be improved here is the fit between the front of the fin and the fuselage (see pictures). The section of the fin that fits into the fuselage is tapered like the fin itself. However, the cutout in the fuselage is squared - so there is a small gap. Nothing serious, but an opportunity for improvement.
I began the installation of the horizontal stabs. I followed the instructions for inserting the stab wing tube and then installing one horizontal stab. The fit seems to be ok - maybe just a hair sloppy. There are hardwood dowels in the top and bottom of each stab for attaching to the wing tube. The instructions call for drilling a hole through the hardwood dowel in the top of the stab. There is no mention of the hardwood dowels on the bottom of the stab. I would assume this is to minimize the chance of the 4-40 socket head cap screw coming loose and falling out - but in 3D aerobatics does is really make a difference as to what is up and what is down (only when transporting the plane I suppose). Anyway, I chose to use the bottom dowels as the attachment point - I think it makes for a cleaner finished product.
The instructions call for pre-drilling a 1/8" hole for the stab retainer bolt. The purpose of this is to drill through the fiberglass wing tube insert in the stab. A hole is already drilled through the hardwood dowel, so just use it as a guide. I used a 7/64" bit instead of 1/8" because it gives a tighter fit for the 4-40 bolts. The instructions then call for inserting the wing tube in the fuse and then installing the stab half. Make sure the wing tube is centered! Carefully remove the stab and wing tube together and then drill a pilot hole to tap 4-40 threads into the tube. After drilling the pilot hole I didn't take the tube out of the stab to tap the threads - figured it would be too hard to align again. Insert a 4-40 bolt and then re-insert the wing tube with the stab half still attached. Then slide the other stab half on and make sure everything is tight against the fuse. At this point you need to drill the pilot hole for the other stab while it is attached to the plane - much harder to do with a hand drill. Then tap the threads for that half. The instructions then call for gluing hardwood into the wing tube where each bolt attaches and then tapping threads into the hardwood. This gives a little extra holding power and security. The instructions tell you several times not to take the wing tube out of both halves of the stab at once. Otherwise you will have a very hard time getting everything aligned again so the bolts can be re-inserted. I suggest that you put several witness (alignment) marks on the wing tube and stab halves just in case you do need to remove them both at the same time for some reason.
This is one other area where I am disappointed in the quality of materials and workmanship (yes, I know - IT'S AN ARF!). The anti-rotation pin in one of the stab halves is very poorly inserted and glued, as well as the hole itself is very poorly drilled in the root rib of the stab. There is a very noticeable space around the pin - enough to get multiple toothpicks in if so desired..... I used a toothpick to work thin 30 minute epoxy into the gap - probably 1/4 teaspoon....... and it still didn't fill gap. I will let that dry and then glue some filler material in this area. The anti-rotation pin on the other stab half looked much better. All-in-all, AW just lost another point in the Quality of Materials on the Satisfaction Meter below......
8/19/2001 - I continued some work on the tail section today. When I examined the anti-rotation pin in the stab it still had a gap - the glue had simply drained into the hole area around the pin. So, I glued some sections of toothpicks in the gap around the pin (see new photo). I think this will be fairly sturdy now. After the glue dried I "dry fit" everything. There is a slight gap between the left stab and the fuse. This is due to a section of the stab root rib having a very slight bow in it. Not enough to worry about, but it leaves a noticeable gap. The wing tube for the stabs has a little play in it - well enough for me decide to do something about it. I coated the middle section of the wing tube with 30 minute epoxy and will let it dry overnight. I will lightly sand and then test the fit. I think this thin coat should be enough to tighten up things. If not, I'll keep applying coats of epoxy until I get the desire fit.
I also installed the egress points for the pull-pull cables. I determined where they need to exit by sitting the fuselage flat on a long sheet of paper and tracing the outline of the fuse. Then marked where the servo arms and control horns will be on the rudder. Connected the dots and where the line crossed the fuse is where the holes need to be. I then marked on each side of the fuse where the height of the servo arms will be. Drew a line from this point to the control horns and "X" marks the spot. Be careful - if you mount the rudder control horns approximately where they are shown in the picture then the line between them and the rudder servos is likely to pass right through the 3/8" stringers in the side of the fuse. This is definitely not what you want. So - mount the rudder control horns about 3/8"-1/2" above where they are shown in the photographs and you will clear the stringer. I used Klett Pushrod Exit Guides to finish off the exit points.
One thing I also did was to add a removable tail weight bay. I learned this trick from watching Jason Shulman's video. The rudder servo cutouts in the tail section work just great for a 3/4" piece of wing tube inserted in a phenolic tube. I glued the tube between the servo cutouts on each side of the fuse. As you can see from the pics, not my best work, but it's covered up so nobody will know. I made hatch covers for each side. I can now cut different lengths of 3/4" wing tube and fill them with lead. That way I can change the CG without having to add stick-on lead weights or move everything around. Great tip from Jason!
8/22/2991 - After the light coat of thin epoxy that I applied to the stabilizer wing tube dried, I gave it a light sanding until it fit snug in the wing tube. This eliminated almost all of the play that had existed before. I then fit the stabilizers to the fuse. The right stab (as viewed from the front) stab fit nice and tight. The left stab, which had the slight bow in the root rib left a noticeable gap. You can see this in the pics.
I then drilled all the holes for the Robart Super Hinge points. I used a Robart Hinge Point Guide to help with drilling the holes. This little tool works really well, and if you are a hinge point person I would definitely recommend that you add one to your tool kit. I only goofed on one hinge point hole, and this was due to my alignment, not the tool.
I melted some Vaseline and coated the hinge joints before gluing. This helps to keep the epoxy out of the hinges joints. Not 100% foolproof, but sure helps. I then mixed up small batches of 30 minute epoxy with some K&B Micro-Balloons Filler mixed in.. I cut off the tip of a Q-Tip and used it to coat the inside of the hinge hole, and then applied the epoxy to the hinge point. Careful insertion, alignment, and wiping of excess glue made for nice hinges all the way round. Next I will install the servos and control arms in the rudder and elevators, and then mount those control surfaces.
8/30/2001 - I finished up the tail section, including installing the elevator servos and control linkages. Additional pictures have been added - see below.
9/24/2001 - As I am nearing the end of this assembly (just waiting on the new battery recycler to check out the batteries) I encounter one more problem. Double checking everything and find that the horizontal stabs are wobbling. I don't know if the wing tube is wobbling in the fuselage, or the tubes inside the stabs are loose or what. But it is enough of a problem to require attention. I wouldn't fly the plane in this condition. So now I must disassemble the tail section and find out what is wrong. As you know, this was a problem early on with the stab tube not fitting snugly. I thought I had it fixed. Don't know if I bumped it or what, but something is wrong. Check back for updates.
9/25/2001 - Took the stab off tonight to see what was up. The stab was noticeably loose on the stab tube. The balsa on one side of the anti-rotation pin was cracked. Not sure why these problems occurred, but I probably bumped it when I was turning the plane over to work on it or something. Don't think it is a problem with the kit. So, patched everything up and them used a high tech method to tighten up the stab on the stab tube - wrapped masking tape around the stab tube in several places. Worked fine and the stab is now tight again.
CLICK HERE FOR PICTURES -- (Back to Top)
Pull-Pull System (8/25/2001) -- (Back to Top)
The pull-pull system was fairly easy to install. I used Rocket City Swivel Link Offset control horns (Stock #69C) on the rudder. Sullivan .032 (1/32") stainless steel cable (# S522) was used for the cable system. I used DU-BRO 4-40 Rigging Couplers to attach the cables to the control horns.
I had to drill a hole through former F7 to allow the pull cables to have a straight shot between the servo and the control horns. While I usually do not recommend removing covering, this is one time that I think opening the bottom of the fuselage was a good choice. I used my Dremel with the 90-degree attachment to easily drill these holes. Otherwise you would have to have a drill bit attached to a long dowel or some other method to reach F7. Marking where the hole needed to be would also be a pain.
I used two wooden rulers taped on each site of the rudder to hold it in position while I measured and attached the pull-pull cables (see pics).
Luckily, my egress holes were just about perfect. The cables are centered in the holes and there is not much rubbing. The cables slightly rub the panels I made to cover the tail-weight bay, but not enough to worry about.
8/30/2001 - I finished up the pull-pull system. It was really nothing more than adding the second servo in the rudder gang. It took quite a while to get the servos in alignment. I used the two most closely matched servos in terms of throw and travel for this setup since they have the most potential for continual "fighting". Even with all the alignment, adjusting, replacing servo wheels and re-drilling holes for the Nelson servo arms, I still can't seem to eliminate all of the contention. There is no serious fighting going on, but it would be nice to have none at all if possible. I'm not sure this is possible with digital servos. I have read quite a lot of information on JR digital servos (DS8411s in my case) and what I have concluded is (1) there is some level of "buzzing" to be expected and (2) there is a slight amount of minute "twitching" as they continuously try to "center" themselves. On the rudder, if I disconnect one of the servos, then the other one will usually settle down quite nicely. If I connect the second servo, but do not tighten the bolts on the swivel links, then there is very little fighting. It's only when I tighten the bolts on the swivel links that I get any noticeable contention. I have checked and rechecked the control rods, swivel links, servo arms, etc. There seems to be no binding of any sort. I may try running both servos off one receiver with a Y-harness just as a test to see if it makes any difference. I don't think it will, but it's worth a try. I may also try voltage regulators to see if they make any difference.
8/31/2001 - I realigned the rudder servos one more time tonight. This time I started by ensuring the center points of the swivel connectors on the connecting rods were the exact same distance apart as the center points of the gears on each rudder servo. I did this by using plastic bolts to connect each swivel to the servo gears. Click HERE to see pictures of this process. I then connected the Nelson servo arms of the back servo to a un-drilled servo wheel. I then turned on the transmitter and receivers. I placed the servo wheel on the servo gear, (making a witness mark to ensure that I place back on correctly later) and then carefully aligned the servo arm on the wheel, clamped it in place with a small clamp, and then marked the holes for the servo arm. I then used a straight edge to ensure the holes in the servo arm where the swivels connected were on center with the screw hold that for the screw that holds the servo wheel to the servo gear. Everything looked nice and aligned, so I drilled the holes in the servo wheel and connected the servo arms to it. I believe this is about as absolutely aligned as I can get these servos. Still a little contention, but I think it is mostly due to the servo jitter, not the fact that the servos are out of alignment.
When I hooked up the elevator servos they buzz and slightly twitch constantly - actually more than the rudder servos. This is in line with what I have been reading, so for now I am going to assume that this is close to "normal". So, if any of you out there have any experience in this area, please email me at robert.keahey@gte.net or call me at 972-618-6571. I would really appreciate some help here. And yes, I have read all the pros and cons of the different brands of servos, but have made the investment in JR. You can check out the pictures in the next section (Batteries, Switches, Wiring) to see the rudder servo setup.
CLICK HERE FOR PICTURES -- (Back to Top)
Batteries, Switches, Wiring (8/30/2001) -- (Back to Top)
I have been busy for a few days installing the batteries, switches, wiring, finishing up the pull-pull system, and installing the elevator servos. See the update on the pull-pull system above.
I am using JR integrated switches all around. I have had good success with these switches and they seem to be reliable. They have the charging jack integrated in with the switch and you can close the cover to the charging jack to keep out dust, dirt, and oil. I built my own long servo leads for the elevators and outboard aileron servos. I used 22 gauge stranded wire (7/30) with PVC covering. I considered using (19/34), and may still do so at some point in the future if I detect any interference. I just can't seem to find it within reasonable driving distance, and have yet to find a place I can order it. I soldered the leads instead of using connectors. I don't like having another potential point for failure plus some signal loss across the connectors.
I am using dual 2000mah 5 cell (sub C) packs from SR Batteries. These guys make high quality batteries - but you can expect to pay more for them. I debated going with 1400mah packs to save weight, but with 8 digital servos, throttle servo, and a smoke pump, I didn't want to take any chances. I wanted to use 2400mah Duralites to save weight, but Performance RC says they will not be back into production until the Spring of 2002. So for now I will sacrifice some weight for extra amperage.
I am using two receivers (JR549X PPM). Each receiver is connected to its own battery pack. I thought about using EMS Jomar optical isolators, but couldn't see adding anymore weight at this point. Once again, if interference rears its ugly head then I may have to go this route. The plane is basically split in half. Each elevator half is on a separate receiver. I am using an EMS Jomar servo reverser on one of the elevator halves. The aileron servos in each wing will be split across the two receivers. One receiver will drive the throttle servo, the other the smoke pump. The rudder servos are also split across the receivers. The theory behind this is that if I lose one battery or receiver, I will hopefully have one aileron servo on each wing, one rudder servo, and at least one elevator half. I have flown a plane with only one elevator active before, and other than being a little sluggish, it managed to fly ok until I could get it back on the ground.
The compartment looks a little crowded, but there is actually more room than appears. Everything is buckled down nice and tight. One thing I considered, and may still do is placing a battery on each side of the wing tube. The reason I didn't was because of the size of the fuel and smoke tank (32oz each). They are just slightly off center (ahead) of the wing tube and I figured the current battery placement would provide a reasonable offset in weight. Only the balance test will tell if my theory holds.
8/31/2001 - I received feedback from several modelers on the use of servo reversers. They suggested that I use this as a last method to reverse the servo. This is due to a tendency for some reversers lose their trim setting due to heat or other factors. Suggested methods were to have the factory reverse the servo for me, or use the radio to reverse it. I don't know why this latter method didn't dawn on me in the first place - old age I guess.... I have used this method before. I plugged the servo that previously had the reverser into the AUX3 channel. I programmed mixed the elevator to AUX3 on my JR 8103. I reversed AUX3, and then set the rates to match the other elevator, then the offset to align them. Worked like a charm. This way, even if I lose a receiver, I will still have at least one of the elevators working. Ain't technology great. Just wish my brain worked as well!
CLICK HERE FOR PICTURES -- (Back to Top)
Fuel/Smoke Tanks (8/31/2001) -- (Back to Top)
Well, finally got some Tygon today - only had to drive 30 miles round trip to get it. At least I was able to finish installing the fuel and smoke tanks. I mounted both of them under the fuselage platform. I used a Dubro Kwik-Fill fuel valve for the gas tank and a simple fuel dot for the smoke tank. I used Fourmost 3/32" bulkhead fittings for the overflows and mounted them through the landing gear plate behind the landing gear. Not much exciting stuff here, so I will let the pictures speak for themselves.
9/8/2001 - I covered the fuel/smoke tank access cover and installed it. New pictures have been added below.
CLICK HERE FOR PICTURES -- (Back to Top)
Spinner/Prop (8/31/2001) -- (Back to Top)
I am using a Dave Brown Vortech 4" Spinner and a Menz 27x10 prop. I used a Desert Aircraft prop drill jig to drill the holes in the spinner and the prop. Naturally I had to open up the holes on the spinner to accommodate this size prop. I used the masking tape and scroll saw (with a hacksaw blade) method to rough out the opening, then a Dremel with a sanding wheel for the finish work. I used a 5mm drill to drill the holes and had to "re-drill" the holes in the prop to clean them out. I finally used a 5.5mm drill on the backplate of the spinner because the prop bolts kept trying to cut threads in the aluminum due to the tight fit. After several fitting and re-drillings everything lined up with a good tight fit. The Menz prop was very close to being in balance and only a very small amount of sanding was required to get a good balance.
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Ignition System (9/1/2001) -- (Back to Top)
The ignition system was fairly easy to mount since there is lots of space behind the F1 former inside the engine box. I toyed with the idea of mounting it on top of the engine box in front of F1, but there was too much kink in the spark plug wires and I had to bend the battery lead and timing lead to make it fit, so I abandoned this idea.
I wrapped the ignition in several layers of heavy duty foil to help prevent interference. I glued 3 pieces of 1/8" x 1/4" rubber on the floor of the engine box, then mounted the ignition on top of the strips using 3/4" 4-40 socket head cap screws. I ran the spark plug wires and timing lead through the lightening holes I had made in the top plate of the engine box. As it turns out these holes worked really well since the gave the path of least resistance for the wires and leads. I then wrapped the wires and leads with foam to prevent chafing.
I am using a JR Heavy Duty integrated switch and charging jack - same as on the receivers. DA 100 recommends this switch in their literature, so it should work fine. I cut the leads as short as possible and the re-soldered the connectors. I used 20 gauge wire to connect the switch to the ignition. Assembling the battery connector for the ignition was fairly easy, and the DA 100 instructions are very good.
I am using a 5-cell 1400mah battery pack for the ignition.
CLICK HERE FOR PICTURES -- (Back to Top)
Final Cowl Mounting (9/5/2001) -- (Back to Top)
I finished mounting the cowl tonight. I decided to use a "blind mount" method. I have never tried the before, always resorting to the old bolts-through-the-cowl method. I have been conversing with Leroy Brandt (owner of Branline Models) who is assembling this plane for a friend. He suggested this method and gave me the instructions. You basically make two "cowl formers" to attach the cowl to the F1 former. There is a top and bottom former that are cut to the shape of the cowl. The reason that you cannot make a one piece former that goes all the way around the cowl is that most twin cylinder engines fit VERY snugly in this cowl, so you have to leave space on the sides to clear the cylinder heads and spark plug wires.
I started by temporarily mounting and aligning the cowl using masking tape. I then made a template of the bottom former - obviously the bottom of the cowl has to be cut at this point for the mufflers and airflow - otherwise you can't get the template in and out of the cowl. You can't simply make the former in the cowl while it is off the plane since it will not fit snugly along the sides of the fuselage (at least that's what I found). So, with lots of trial and error and C-clamps, I got the bottom cowl former to the shape and location I wanted (be sure to make witness marks on the F1 former so you can remount the real cowl former in the proper location) . I used 1/4" light plywood with lightening holes to make the actual bottom cowl former. I mounted it and then drilled holes through the mounting tabs (see pictures - holes at very top) into and through the F1 former. I then installed 8/32 blind nuts from the backside of F1, and then bolted the bottom cowl former to F1.
At this point I removed the cowl and then removed the bottom cowl former. I taped plastic wrap to the front of F1 and under the bottom and along the sides of the fuselage. This is to prevent glue getting on any of these surfaces. I then re-installed the bottom cowl former and mixed up a batch of 20 minute "finish cure" epoxy. I mixed in some micro balloons, which I have found makes a very strong bond, but doesn't have the brittleness of just pure epoxy. I waited until the glue was close to "kicking" and them covered the edges of the cowl former. I then very carefully mounted the cowl and aligned everything again. This is a good time to put the spinner back plate on to ensure you have proper alignment and clearance between it and the nose of the cowl.
I then used a band clamp (come-along) to hold the cowl in place while the glue dried overnight. In retrospect, this may have been a bad idea. As it turns out, one side of the cowl is about a 1/6" or so out of alignment with respect to the yellow stripes down the side of the fuselage. I think the band clamp may have twisted the cowl slightly.
The top cowl former was much easier. All you have to do is make a blank larger than the shape of the top of the F1 former. Drill 2-4 holes (depending on your preference) through the cowl former and through F1 to accommodate 4-40 bolts. This time, install the blind nuts in the front side of cowl former. This allows you to install the bolts through F1 from the hatch side into the cowl former (you will have to cut small recesses into the front of the hatch cover to accommodate the heads of the 4-40 bolts). I then mounted the blank cowl former and marked the outline of the top of F1. Removed the cowl former and cut and sanded it to shape. I used 1/8" plywood and then glued 1/8" balsa to it and sanded it back to the original shape of the plywood. I then repeated the same gluing process - cover the F1 former with plastic wrap, mount the top cowl former, mix up a batch of finish cure epoxy, apply the glue, mount the cowl, align, clamp, and let it cure. At this point you should do a test fit of the cowl with the mufflers and spark plug wires installed to ensure that you can actually get the cowl on the plane. If not, make mods with your Dremel tool as necessary.
The next step is to reinforce the cowl formers. This is done by applying 2 ounce glass cloth to the former and cowl to make a solid, strong bond. I cut small strips (about 3/4" by 1") of the cloth on a diagonal to the weave (makes it easier to lay it in the corners). I then mixed up a batch of finish cure and started laying the cloth strips along the joint of the cowl and cowl formers. I overlapped them as I went along, and in a few spots doubled them up. Don't get too many layers or too much glue - your cowl may not go back on and you will have some sanding to do! I laid up these strips all around both sides of both cowl formers and then ensured that everything had a good coating of finish cure and that everything was nice and flat. Let it dry overnight - a nice strong bond.
You then mount the cowl by inserting the bolts in the top and bottom cowl formers and you have a nice clean look. See for yourself! Thanks Leroy for the great tip and instructions.
9/9/2001 - Added Desert Aircraft decals on cowl. Check out picture below.
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Hatch/Canopy Mounting (9/5/2001) -- (Back to Top)
I thought mounting the hatch cover would be fairly easy. The mounting system is fairly well made, with a piece of 1/8" ply glued to the bottom of the hatch and 1/4" side mounts glued to each side of the 1/8" ply. 1/4" triangle stock is used for support, and then the 4-40 blind nuts are mounted in the side plates. At least I think they are supposed to be 4-40 blind nuts. I could not get 4-40 bolts to screw into the blind nuts. I looked at the blind nuts under my magnifying glass and they looked "dirty". So, I re-tapped them with a 4-40 tap and they worked ok. This is one point that I hope AW takes a look at with respect to the manufacturing process. I think the blind nuts are just jammed or hammered in and this is probably what messed up the threads.
I had to remove about 1" of the side plates to accommodate the switch harnesses. I also had to remove a section of the front of the hatch (where it meets F1) to allow for the triangle stock that I glued behind F1 to support the engine box top plate. I also cut recess holes in the front of the hatch to accommodate the heads of the 4-40 bolts that hold the cowl in place.
I then mounted a Goebel instrument panel. The panel is actually made for the front seat dash, but I modified it for the back seat and I think it looks ok. I have a 33% pilot bust from Model-Graphics.com but I think he is going to be too big. I may have to swap him for a 27-30% pilot.
9/8/2001 - As expected, the 33% pilot bust was too tall to fit in the cockpit. I tried a 27% pilot bust and it just looked lost in the canopy. So - you know me - I had to rebuild things to suit me..... First I cut 3/4" off the bottom of the pilot bust using my bandsaw. This was still not enough, so I made a recess in the hatch floor to accommodate the pilot bust. I cut out a section of the covering and balsa in the hatch floor. I then used a chisel and carefully dug out the styrofoam. As careful as I was, I still busted through the bottom of the hatch. One of the pieces of 1/16" balsa on the bottom of the hatch was so thin that it was like tissue paper. After cleaning out the recess, I then cut a new piece of styrofoam about 3/8" thick to fit in the recess, and glued it using aliphatic glue. I then cut a new floor from 1/8" balsa and covered it with Ultracote. I made new side walls from 1/8" balsa and covered them. I then glued everything in place, and recovered the top of the hatch, overlapping the covering into the recess. Now the pilot bust fits perfectly, and I think the proportions are better with the 33% steely-eyed, fearless, 3D guy.....I glued a hold-down block with a 3.5" nylon 1/4x20 bolt inside the pilot bust. I left about 1.5" of the threads sticking out of the bottom of the pilot bust so I could secure him through the hatch. Wouldn't you know it, when I placed him in the hatch and drilled the hole for the bolt it line up perfectly with the F4 former.... So, I had to move him forward about 3/8", which makes him look like he is farsighted and he is trying to see the instruments up close....!
I also "mounted" the canopy today. I use that term loosely because this is one of the jobs that I dislike the most. Seems like whatever method I try I cannot get a nice clean fit. All you scale guys can go ahead and give me a round of raspberries, because I used hard mounts at strategic points to ensure that the canopy stays on in flight. I know, takes away from the visual effect, but mounting canopies is not my forte. I ironed on a 1/4" strip of Ultracote around the edges of the canopy to hide the glue line. I used Wellbond to glue the canopy to the hatch. I put the canopy in place and then inserted the screws in one side. I could then lift up the other side slightly and put small amounts of Wellbond under the edge of the canopy using a Popsicle stick that I had sharpened to somewhat of a flat point. I then taped that side down and repeated the process on the other side. As hard as I try, I cannot seem to avoid some of the Wellbond squeezing out past the Ultracote stripe. I will probably iron on a strip of Ultracote to completely seal the canopy to the hatch.
After I got everything taped into place I notice that I must have somehow bumped Mr. Pilot Guy's microphone - it's now about nose high..... Oh well. I know there must be some voodoo magic associated with canopy mounting - I just don't know how to practice it....... More pics have been added at the link below.
9/9/2001 - Removed all the tape and was fairly pleased with the results. The Wellbond dried fairly clearly - only one small spot that I think will finally cure out. Other than Mr. Pilot Guy picking his nose with his mike boom, it looks pretty good. I will seal the bottom of the canopy to the hatch with Ultracote and that should be the last of my canopy mounting woes for a while! See new pics.
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Engine Testing (9/8/2001) -- (Back to Top)
Today was the first test of the DA 100. Charged up everything last night and was raring to go this morning. I am swinging a 27x10 Menz prop and using a Dave Brown Vortech 4" spinner. J&A Engineering mufflers and a Harris smoke pump. For break-in I am using Lawn Boy Generation II All Season Ashless engine oil mixed at 32:1.
Starting procedures call for closing the choke and opening the throttle to about 1/4. Flip until it pops then open the choke and set the throttle to idle. Four flips with the choke on and on the fifth flip it started. How about that! What a strong engine! I didn't tach it today, but let's just say my 18 year old son had his hands full holding this baby back at full throttle.
Did a range test with the engine running. Of course, with everything shaking the way it does, it's hard to tell if you are getting any true interference. I had to walk at least 150' away with only 1 antenna section extended before I could notice anything that looked like a glitch. I think I will be ok so far on the interference issue. If not, more shielding (probably printer's aluminum).
Aileron Mounting (9/9/2001) -- (Back to Top)
I finished up mounting the ailerons and servos today. I used seven Robart Super Hinge points in each aileron half. This was once again fairly easy using the Robart Hinge Point drill guide. 30 minute epoxy was used to glue the hinges in place.
I used Rocket City Offset Swivel Links (Stock #10B) for the control horns. Like the elevators, in order to get the hinge point of the control horns fairly close in line with the aileron hinges, you have to drill very close to the front edge of the hard point that is installed in the aileron. Once again, a little extra "beef" here would have been nice.
The servo mount cutouts are very deep in the wing - so deep that the bottom of the servo arm almost touches the wing surface. So I added a 3/16" piece of light ply to each mount. This brought the servo up above the wing enough to deal with the throws. AW recommends that the control horn pivot points be no less than 1" from the surface of the ailerons in order to prevent flutter. With this distance, having the servos buried in the wings as deep as they were would be a problem I even attached the control linkages to the top of the Nelson servo arms in order to get a decent alignment (see pictures).
The instructions also indicate to attach the control linkage as far in on the servo arm as possible for maximum torque. I used the center hole (1") on the Nelsomn 1.25" servo arms. I think this will be ok for normal flying but for 3D stuff I am going to have to move the control linkage to the outer hole (1.25") in order to get maximum deflection. One other troublesome thing wit the current setup. If the gears were to strip in one of the servos then the arm can deflect to the point that you have a 180 degree angle (straight line) between the control horn and the center hole of the servo. This could cause the aileron to get locked in a full-deflection. Not good. Moving to the outer holes should hopefully eliminate this.
I mounted the control linkages to the top of the Nelson servo arms. I did this for two reasons. First to allow maximum throw. The Nelson only allow about 30 degrees of throw without spacers to allow the swivel arm to move in between the two arms. Second, I needed to get a better alignment between the servo arm and the swivel point of the control horn. I used washers for spacers, but am beginning to think I could have gotten away without them. I haven't applied any mathematics to this yet - so any of you control linkage experts out there please feel free to give me some help.
All-in-all, not too hard of a task and the results were pretty good. Plenty of throw in each direction for now.
9/10/2001 - Sealed all the control surfaces. Since there is a lot of real estate in which to work when the control surfaces are fully deflected, this was a fairly easy task. Used the old "creased down the middle" strip of Ultracote (it would be nice if AW provide some extra covering material for this) and then a tongue depressor to hold it in place until it is tacked down. Took about an hour total after I had everything set up. Added a pic - see below.
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Weigh In (9/10/2001) -- (Back to Top)
Tonight I assembled the complete components and did a weigh in. I was hoping for 26 lbs, which is the high-end of the advertised range. What I got was over 27 lbs. Well, I was mildly disappointed, because I figured 26 or less would be achievable only if you used one receiver, one four cell receiver pack, a four cell ignition pack, one rudder servo, no smoke system, no additional bracing, and the lightest engine you could find..... My plane doesn't meet those specs - two receivers, two 5 cell 2000 mah sub C packs, a 5 cell ignition pack, smoke system, two 32 oz tanks, two rudder servos, extra bracing and a strong engine box (as much as these big planes vibrate I would recommend nothing less here). All-in-all I think it will still be a great flying plane. I can always cut back to 4 cell packs, drop a rudder servo, no smoke, etc..... but that takes what I consider some of the reliability and fun (smoke - never fly without it!) out of the plane. We shall see.
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First Pics of Assembled Plane (9/10/2001) -- (Back to Top)
Tomorrow night (9/11) is the club meeting and I plan on showing the plane, so I wanted to get everything into final assembly stage. I still have to mount the new tailwheel when I get it, and decide which decals I want to apply. Also need to seal around the canopy - AND I WILL BE FINISHED!! The pics aren't very good since they are in my cluttered garage, but you can get the idea. I will take some outside on the grass in a few days.
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Cooling Baffling (9/14/2001) -- (Back to Top)
I started thinking about how I want to construct to cooling baffling inside of the cowl to direct the airflow over the cylinders. I asked Leroy Brandt about this and he gave me some good advice - as well as pointing me to Cactus Aviation's web page that describes the need for cooling and how to construct baffling - click HERE to go to their site. I stood there looking at the engine in the one piece cowl and was thinking how am I ever going to get the right profile? Wishing I had a profile tool (like one of those tools that has lots of steel rods held parallel to each other, and when pressed against a surface they conform to its shape) that would fit inside the cowl and let me copy of the profile of the cylinder heads.. But at the same time, you have to get the profile of the cylinder head with respect to the profile of the cowl opening. So I decide to make my own crude version of a profile tool.
I started by squaring off the ends of a bunch of popsicle sticks. I then inserted the first stick into the cowl opening and butted it up against the cowl at the nose. I then put witness marks on the popsicle stick to mark the contour of the cowl opening and where the stick touched the fin on the cylinder. I then added a second stick, marked it in the same manner, and then taped the two sticks together. Added another stick, marked it, taped it to the others. Repeated the process until I had the profile of the cowl opening relative to the cylinder heads. I then marked the underside of the sticks to get a general profile of the front of the cowl. This will let me know where to cut the baffle to have it fit as snugly between the cowl and the cylinders as possible. See the pictures below for clarification.
Now - how do you get everything lined up to cover the other areas inside the cowl? My next step is to make a template of the profile of the engine. I can then lay my profiles that I made last night on top of the template, using the witness marks for reference, and get a relatively good outline of the entire front of the engine and the front of the cowl. How to get a profile of the engine? Well, I went to the Desert Aircraft web site and grabbed to top view of the engine from their CAD drawings. It's smaller than the actual engine, so I measured from the outer most fin on the right cylinder to the outermost fin on the left cylinder to get the true dimensions. I then scaled it up using Photoshop and saved it as a JPEG. The file is included in the pictures section below for your convenience. From this, I can now make a template of the front of the engine. That's all for today - will continue this process tonight.
BTW - IF THERE IS AN EASIER WAY TO DO THIS PLEASE LET ME KNOW!!!! Email me at robert.keahey@gte.net Thanks!
9/16/2001 - Well, I have discovered a new place and it's called "baffle hell". I just returned from there...... I finished the baffles tonight, and although pleased with the results, I am glad this activity is over. If you don't like cutting, sanding, dry fitting, taking the cowl off and putting it back on - about a hundred times - then this is not the exercise for you.
I took the image of the top view of the engine and cut it out and then made a template out of an old piece of plastic that I had laying around. I then matched my crude, but effective, guides that I made from popsicle sticks to it. Was surprised to find that the guide was fairly accurate, so maybe it's not such a bad method after all. I then cut two rough test blanks from balsa and used them for the initial dry fit. The dry fit process is slow and tedious, but well worth the money in the end. I glued a piece of 5/16" balsa stock under each opening in the cowl to provide a good gluing surface to which to attach the bottoms of the baffles. After many iterations, I got the balsa blanks to fit like I wanted. I then transferred them to 1/16" light ply and cut them as accurately as possible since you want to get the baffles as close to the fins on the cylinders as possible (about 1/16" according the the Cactus Aviation instructions). More dry fitting with the final blanks, and then glued them in place. Now, on to more measuring, cutting, sanding, fitting....... To make the sides of the baffles I used card stock to cut out blanks. This again is a slow, tedious process. Even with all the cutting and fitting, the fit is still not as snug as I would like, but it's out of sight so as long as the glue joints hold it doesn't really matter. After getting the test blanks as close as possible, I then cut the sides from 1/16" plywood and glued them to the bottoms of the baffles. I used 1/4" balsa triangle stock in a few places for added support.
All-in-all, the results turned out pretty good. Everything seems relatively tight and I don't think the air will have many places to escape other than over the cylinders, which is what we want - right? I will paint the baffles black and then should hopefully be through with this task.
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Tailwheel (9/26/2001) -- (Back to Top)
I finally got the Haigh Tailwheel, which had been on backorder for a while. This is a fairly easy mounting procedure. Drill a hole in the bottom of the fuse in the plywood hardpoint, install the tailwheel, and then install the hold-down tabs. I then drilled a hole for a 4-40 threaded rod through the rudder about 1/2" from the bottom. I drilled the hole as close to the hinge line as I could to minimize the sweep of the rod. I then put thin CA in the hole to harden the balsa as much as possible to prevent the rod from wobbling in the hole over time. This would have been a good place for Aeroworks to place a plywood hardpoint since most people will probably install this type of tailwheel.
I then screwed a plastic pivot point onto the rod about 1.25 inches from the rudder. Next was to make a connecting rod that goes from this pivot point to the tiller on the tailwheel. I used a Robart screw-on clevis with a 2-56 socket head cap screw and nut to attach the clevis to the plastic pivot point. A little Locktite was applied to ensure the screw doesn't come loose. I then used a Robart 2-56 swivel link to connect the 2-56 rod to the tiller. I bent the end of the tiller slightly upward to provide a direct line of sight from it to the plastic swivel point. Made sure the rudder was dead-centered, adjusted the swivel link for the proper length and attached it using a 2-56 socket head cap screw and a nut with Locktite. Everything lined up very nicely with clearance at full rudder deflection and no binding.
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CG (9/26/2001) -- (Back to Top)
I use the sling method for balancing my planes. I have found this method to be reliable and safe since there is little chance of the plane falling off the balancing device. If you aren't familiar with this method email me and I can send you some information about it.
I checked the balance point by leveling the plane at two different points. The first was on the flat surface of the horizontal stab, and then on top of the rudder. Both points ended up very close to the same balance point, so I feel confident that the correct CG was located. The CG ended up about 5/8" in front of the wing tube. The assembly instructions call for the CG to be 1" in front of the wing tube, so I was fairly close and at this point don't plan on moving anything around to achieve a "perfect" balance. I think the plane will fly well at the 5/8" balance point.
So now the only thing standing in the way of the maiden flight is to recycle the batteries to ensure that they are good. I am still waiting on my new cycler......
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First Flight (11/3/2001) -- (Back to Top)
Well, after what seemed like ages, I finally got the bird into the air. The weather was great - 75 degrees, white puffy clouds, and almost no breeze. After a final checkout and engine test it was time to fly.
Take off was uneventful. With the DA 100 up front I needed no more than 75 feet of our 350 foot runway to get the bird in the air - and this was being "conservative". Roll-out was nice and straight and very little rudder correction was required.
Downwind turn and time to trim her out. Just a slight tendency to nose down so 2 clicks of up elevator and level flight was achieved. A slight tendency to roll to the left and 2 clicks of right aileron and everything is nice and straight now. No rudder corrections required to fly on a string.
Make a couple of laps around the field just to get the field. Decide that I have more expo programmed in than I like, but will fix that later. All control surfaces were set per the instructions. First thing to notice is that 12 deg of up/down elevator at low rates is not enough! I took off with the elevator set to high rate. Glad I did.
Aileron rolls are nice and crisp even at low rates. No tendency for the nose to drop. Loops are as big as you want them. Noticed that at the top of the loop when I cut power back the plane really wanted to "float" - hmmmmm...... Vertical up lines and down lines are nice and straight with little rudder input required. Guess that mandatory 2-3 deg offset that I complained about earlier is not such a bad thing after all! Vertical is very impressive - even with the engine not being broken in yet. Vertical aileron rolls are very impressive.
Knife edges are nice and straight with very little elevator and zero aileron input required. My spotter tells me to do a knife edge on a 45 degree upline. I oblige and he finally says "that's enough!" as the plane almost disappears from sight and is still climbing!
Stall turns are fairly easy, but have to kick in lots of rudder to throw that big tail around (remember - settings are per instructions at this point). Even at that, the plane tends to not want to turn as fast as I would suspect ..... hmmmmmmm..... is there a pattern here..... tail heavy?.......
Slow speed flight is a cinch. This plane is very stable - in fact, very hard to stall (as we shall see later). Will easily turn over and spin.
Snap rolls are very fast, even at these conservative rates. Plane will stop the snap on a dime. No exotic maneuvers were attempted on the maiden voyage. Time to land....
Set up downwind leg and power back. Make a longer than usual turn to set up approach, and then turn upwind for glide path. Everything is looking good so far. Cut throttle back. Throttle trim tab is set a little high just for insurance on first flight. Plane continues to fly straight and level..... hmmmmm.... too much power. Go around and cut trim tab back to lowest idle point possible. Set up on glide patch. Cut throttle all the way back. Plane continues to fly straight and level....... hmmmm....... in fact, it appears to be slightly climbing!! What the heck is going on? Go around again...... cut the trim tab back another notch.....not a good feeling at this point. Line up - same thing, so cut trim tab back one more notch and engine quits..... now I'm dead stick on approach. The good thing is that this plane is very stable. Just let plane bleed off speed and it floats in. Just a hair of up elevator (and I do mean a hair!) to keep her on a good attitude. No visible tendency to tip stall. Plane settles gently onto runway. Time to go clean out my pants....
Contribute first flight landing problems to jitters.... Second flight is once again conservative - no 3D maneuvers at this point. Just trying to get some time on the engine. Time to land. Have my buddy standing next to me who does landings as smoothly as anybody I have ever seen. Asked him to coach me through the process if necessary. Line up - same thing. With engine at absolutely lowest idle possible without quitting the plane wants to fly level or climb!?!?!? Go around - same thing. Go around third time and my buddy is in amazement.... Without applying down elevator and diving at the runway this (my) plane does not want to quit flying. Finally killed engine and glided her in again....... New pair of pants required this time.....
OK - so what is wrong??? Is the plane tail heavy? Straight and level flight is easily achieved at 1/2 throttle and above. Could incidence be wrong? It is just like it came out of the box? Is the big hole in the bottom of the cowl acting like a drogue shoot and lifting the nose? I am at a loss at this point - HELP!!!!
Flight Update (01/26/2002) -- (Back to Top)
Bad weather, lots of work, and travel have kept me from the flightline these past couple of months. I now have about 20 flights on this plane and am very pleased. After talking to Rocco at Aeroworks we determined that my "floating" problem was probably CG related. So I moved the batteries from behind the wing tube to the back of the engine box. The first attempt was not too good because I got some glitching when the engine was running. So I grounded the the ignition to the negative side of the ignition battery with a 6" strip of solder wick. This cured the problem.
All I can say is the Aeroworks Edge 540T and the DA 100 is one hell of a combination. Unlimited vertical is a breeze with this combo. All the power you could possibly want for hovering. I am still tweaking the engine since I only have about 4 gallons of fuel through it so far, but it is getting stronger with each flight.
The CG change dramatically affected the floating problem, but a "touch" of down elevator is normally needed for landing. I have programmed the landing switch on my JR 8103 to accommodate this, but have yet to use it. Plane slows down nicely with the Mejzlik 27x10 and has very nice flair characteristics.
Now that the plane is getting "broken in" I am starting to crank in some additional throws. Knife edge loops are effortless (if you have the nerve to hold them!). Snaps are awesome. I am still working on harriers since I am slowing cranking in the elevator throw. As of now, the plane does not appear to have any tendency to snap.
As I mentioned earlier, vertical on this plane is absolutely awesome. The guys at the field just stand around with their mouths open as I go straight up doing aileron rolls with the smoke on - and finally throttle back to keep from disappearing!
Construction Update (01/26/2002) -- (Back to Top)
I had heard of a few reports of wing failure at the end of the wing tubes. I talked to Rocco at AW and he indicated that there had been a couple of instances where the glue around the "false ribs" at the end of the tubes had come loose and the wing tube "wallowed" around, weakening the foam and causing a failure. He suggested checking the wings ever so often by rocking them up and down and listening for and "creaking" noises. Just to be on the safe side, I decided to go ahead and reinforce them. Rocco instructed me to cut a 1" by 2" section out of the bottom of the wing right past (outboard side) the wing tube retention hard point. On the first wing panel I was surprised to find an approximately 1/2" thick piece of "wing sheeting" (not sure what else to call it) covering this area. There was an approximately 5/8" open space between the inboard false rib and the outboard. It appeared that the first inboard false rib had been reinforced with a piece of light ply and then the whole area covered with the 1/2" balsa. I mixed some 30 minute epoxy and poured it around the wing tube - and to my surprise it ran into the gap between the inboard false rib and the outboard one...... This told me that the inboard false rib had spaces around it where it was not attached to the foam...... So I decided to fill the space between the false ribs with Great Stuff (the expanding weather stripping sealant). In order to keep it from expanding back up into the wing tube I plugged the end of the aluminum with a piece of 1/4" balsa sheeting (just press the tube down on the sheeting and it will give you the outline to cut - finish it up on the belt sander). The Great Stuff did the trick. I then mixed another batch of 30 minute epoxy and poured it around the wing tube. CRITICAL NOTE: The fiberglass wing tube is porous so if you pour the epoxy in it will seep through and you now have epoxy inside your wing tube. To prevent this, coat your aluminum wing tube with a thin coat of Vaseline brand petroleum jelly. Then slide it into the wing tube. Then pour in your epoxy around the fiberglass wing tube and let it cure. Make sure you have Vaseline all around the aluminum tube or you could have a disastrous situation!
On to the other wing. I cut the 1" x 2" opening in the same place, and to my surprise - no inboard false rib! It was about 1/2" farther outboard than on the first wing panel....... This left only slightly more than 1/4" space between the inboard and outboard false ribs. Quality control must not have been quite up to par on the first few planes. I'm sure it has been improved by now. Anyway, I cut another 5/8" or so to expose the inboard false rib and the gap between it and the outboard false and then followed the same process on this wing as I did the other - filled the gap with Great Stuff, poured epoxy all around the fiberglass wing tube and let it cure. After the epoxy cured I re-sheeted the opening with 1/16" balsa and then covered with Ultracote.
I have put the plane through some pretty good paces so far, and there seems to be no loss of structural integrity in this area. I will keep checking it however.
The last thing I will do is order a new aluminum wing tube. The one that I have is about a 1" too short to complete fill both sides of the wing panels to the first false rib (I think this is probably due to the fact that the second wing panel inboard false rib being further outboard than it should have). I will order one longer than needed and then cut it to the proper length. This should hopefully eliminate any potential problems in this area.
***
So ends the odyssey of the Aeroworks Edge 540T ARF. Unless something of great importance needs to be reported, I will call this project complete. I hope people have found some value in this review.
Would I buy this kit if I had it to do over again? Yes, but would probably wait until the second or third production run so some of the bugs could be worked out.&nbs