Bobhend

My Feedback: (1)

I am selecting my next thermal duration F5J, I am new to soaring but an experienced RC pilot. Our RC club has started a sub- group on soaring, we have 15 guys. However , we are not sure how much plane we will need for our field , which is flat farm land growing corn or beans in upstate NY.I am flying the 2 m Phoenix 2000 and have been very satified with it despite having to replace the motor. Icare-RC is selling the 2.6 m Avia made by Topmodel for $300. I am considering buying the plane and then outfitting it with servos, motor etc, from Hobbyking. Has anyone seen an Avia or other Topmodel ? Since I have been able to fly the Phoenix for 20 minutes with the motor off, I am willing to spend this much now. I have looked at more expensive planes and realize the state of the art equipment is a lot more money. However these planes are either capable of hotliner performance, or are extremely light weight. Since we are not , at this point, interested in competition, the Avia looks like a logical choice and a real TD performer. The Avia should weigh about 42 oz , which is a WCL of 3.9.

da Rock

I've got one and it's nice. It's not a floater no matter what the wing loading.

I had an AXI that almost exactly matched the mfg recommended motor so that went in with AXI's recommended prop. It climbs like a rocket. Had I known that and I not had a motor already, I would have opted for less power.

It's really quite an advanced design, definitely not your OlyII weekend warrior. The details all suggest it's purpose is max performance. The 3 position flaps are somewhat of a giveaway on that. In use, they're nice to have, but you will discover more details that take an extra minute or two of build time.

The instructions aren't instructions, they're 4 pages of pictures with labels. It's adequate for sure, but that seems to be Topmodelcz's solution the language problem.

The sucker has the best construction and workmanship I've ever seen in any ARF I've ever touched. The design is also cutting edge. Speaking of edges, look closely at the leading edges. They're carbon fiber rod. You can't see the quality in the glass work of the fuselage, but it's just about perfect for competition. I was expecting sort of a step beyond an everyday thermal ARF, and was quite surprised to see how big a step this is beyond just a weekend flyer. It will do the weekend job for sure, but be prepared to have a touch more effort required to tune and sort the sucker.

It will hunt like gangbusters. With the flaps straight back it's cruise is fast, so fast even the inexperienced flyers will comment. It's 2.5, somewhat narrow chord wing WILL wiggle when it brushes lift. So far I'm still getting used to it. I've had fast hunters before but that was years back and they weren't this fast. I've tried hunting with the flaps at thermal setting, but that's still a work in progress. The flap setting for spoiling or landing is still being sorted too. I've only had a couple of flapped birds. Always preferred spoilers.

I ran into a couple of problems so far. Gotta go right now, so will have to get back to you on them. None were show stoppers, just surprises.

It's worth more than it's price.

Bobhend

My Feedback: (1)

I saw one today, turns out one of the guys purchased it from Espirit. He added dowels to the TE of the wings and drilled holes in the fuse to keep the wing from moving. I will probably get one soon since I have enough parts to finish it. I will use theSK3-2830-1020/18154 Turnigy Aerodrive 1020kv motor whichis $17 at Hobbyking. The Aerodrive is their new motor series; for some reason the tried and true gold Turnigy motors are not available. For servos, probably six of the HXT900 which are $ 2.69. I have some to try but they should be fine. Might have to spluge and get $10 servos.

As you said, the construction is excellent.

Now as for setup, neither one of us knows how to set up the flaps for thermaling, or landing. Since we have a 600 ft field we don't need precision landings.

That motor pulls 20A on 3S in the Phoenix which has a 10x6 folding prop. I don't use full power to launch. Just FYIit pulls 12A on 2S but I saw no advantage to running 2S.

da Rock

Take a look at that guy's Avia, and look closely at the servo installations in the wing. There are a couple of things to notice.

They cast fitted blocks that retain the servos. They fit the servo well and the servos themselves like they were made for them both. They were. TopmodelCZ recommends Hitec 82s for the flaps (metal geared) and ailerons. At first glance those 8 blocks look pretty much the same. They aren't. The pictures show that some are 11mm while the others are 13mm. The pictures showe them used in different places.

Also, the pictures don't show both flap servos. If you wish to use a simple Y harness and not have to use a reversing Y, you'll do what most of us do and install both servos 'facing left' or both servos 'facing right'. If you do that, take a look at the 4 provided servo well/pushrod covers. Items 2-41. You have a decision to make about the flap servo install and 'reshaping' one of the 2-41s.

da Rock

TopmodelCZ suggests you need extensions for the wing servos. There is more to it than that.

Look closely at the holes in the ribs the wire are threaded through. First thing to do is see if you can get the female connector of your extension through one of those holes. The wings I got had holes too small for any extension connector I ever saw. Plan to solve the problem of threading the wings with some additional efforts.

I cut off the servo connectors and soldered on longer wire, then crimped new connectors on the ends hanging out of the wing. About the length you have hanging out........... The wires come out of the wing right over the servos in the fuselage. There isn't much room back there as the battery is going to be shoved back in the fuselage under the wing. You're not going to want a lot of useless wire that requires balling up and shoving into the fuselage somewhere.

about the wing mount...........

da Rock

About the wing mount.........

You'll notice the picture shows one, fairly small plywood plate glues across the fuselage to hold the wing down. You've already seen someone's handiwork to make the wing hold down more secure. Just gluing that plywood on each side of the fuselage ain't gonna hold very long. Personally, I think they did such a weak setup on purpose. Almost anything that'd damage the wing or fuse simply pulls that plate out of the fuselage. I've seen rabid competitors do things like that to save 1/10 oz for a 'winning edge'. I haven't been rabid for a couple of decades now. I supported the plate on each side with a saddle. It'll now cause the wing to be damaged in mishaps so.............

I'm using nylon bolts instead of those strong steel ones provided and rear support help resist the wing shifting.

About the wing shifting.......... It will unless you use steel bolts. And when it shifts, a flap on one side or the other is going to be shifted over the fuselage body and stall it's servo.

I have no idea how your buddy glued in pins that were sufficiently supported by the wing that would be oriented to the fuselage where it could be drilled for those pins. Is the very thin TE of the wing have something stronger sandwiched between the wood skin? I glued supports on each wing under the TE where the support would stick down into the fuselage opening. Make the supports thin enough they don't conflict with the servos.

It's really a glider for a rabid competitor. I'm glad I used to be one, else it would seem a bit much to me now. It does fly nice, but has been quite a bit more than ARF.

Bobhend

My Feedback: (1)

So , the Hitec servos are worth buying to avoid the fit issues in the wing. They are reasonable cost. Can you explain more about 11 mm vs 13 mm ? Regarding the wing servo mounting , as I uderstand it all the servos are mounted the same and the flaps would be right but one of the ailerons would have to be run through another channel to reverse it. This would make it possible to ad crow, flaperon etc. . So it is also going to require custom wiring extensions into the wings. I alterted my buddy and he should be reading this thread soon. Well, I have the order qued up at Espirit but have not put in the credit card yet. Thanks for all your help, the manual is as you said, in need of words and photos.

da Rock

You will see the 11mm and 13mm on the drawings. It makes sense they would use the 11mm for the ailerons as the wing out there is thinner. 13mm would suit the wing thickness where the flaps go. You really have to study everything on the drawings, everything.

For example, they show a soldering iron touching the servo leads in two places. They're basically illustrating that you can't use the extensions as extensions, you'll need to splice in extra lengths of lead to get the servo lead through the wing.

They only show a couple of pictures and leave it up to you to realize what they're "saying".

About the 4 wing servos...........

They provide 2 left covers and 2 right covers.

Their drawings show the right wing from the underside, with the servos depicted, on a couple of pages. I never found a drawing showing the left wing, either from the bottom or top, that showed the servos. Both the aileron and flap servos in the right wing are mounted with servo arm, the top of the servo, toward the tip. Since their servo covers come with 2 lefts and 2 rights, then you have to assume they expect you to mount the left wing servos pointing away from the right wing servos. Otherwise, their covers won't fit over at least one servo. They expect you to mount the two flap servos in a way that will require plugging them individually, not through a Y. Are there other combinations that work? Beats me, I never thought about it much. I was going to mount my flap servos to utilize a Y and my aileron servos to also utilize a Y. So I knew I had one cover to rework.

da Rock

Reworking one of their somewhat soft servo covers is easy. They are like coins with a bulge along one side. You simply trim the bulge away from the coin as if you were going to use just the bulge. Now rotate the coin 180* to cover the opening above the servo well. The side where the bulge was now is oriented to the servo arm and pushrod side of the servo well. Use a glue like canopy glue and glue the bulge down to the coin and you've just turned a left into a right.... or a right into a left.

It looks pretty good. Not perfect, but it's under the wing and out of sight.

Bobhend

My Feedback: (1)

I just ordered one, Espirit models has 10% off for next 48 hours. The shipping is only $13.50, no tax. I rounded up all the parts to finish it with zero additional cost. Thanks for your help, I am sure I will have a few more questions,like where is your CG ? Hmmm ... did I just put a top quality 2.5 m ship together for $ 279 ???

da Rock

Their 2 sheets of pictures might not spell out things for you, but they've got an excellent couple of pictures of the balancing and it includes a rather exact range. Stay in that and you'll be good to go.

With gliders, we've got an excellent way to check and trim for CG. Hand glide the sucker.

Hold the fuselage right about where you've got the CG located. Walk briskly directly into the wind. Feel what the glider wants to do in you hand. Adjust the elevator trim if needed so it feels good in your hand. Now jog into the wind. Still feel good? Adjust until it isn't trying to lift off or push your hand down. Once it's neutral at a jog.... Walk back to the downwind edge of your field and jog into the wind again, only this time push it forward and let go. It's going to be trimmed at landing speed but might need a click or two to get max distance. Be prepared to walk aways to where it touches down. Don't do this in your front yard.

Bobhend

My Feedback: (1)

The Avia is due in tomorrow and I am planning the servo wiring. I am going to wire all servos to their own channel so I can program any mix I want. What wire gage do I need for the aileron servos ? My servos are not high drain so I am thinking 24 gage. The flaps runs are shorter but the current is higher so 24 ga again. Since the connectors don't fit thru the tubes I am not clear yet on how to do it. I'd like to run the 4 extensions direct to the receiver and not use the multiplex connectors. I would take an extension, remove the socket pins, cut and splice it onto the servo, fish it thru and re-assemble the connector that plugs into the receiver.If a servo fails it means reversing the process etc.

ps My buddy is probably going to use your idea to prevent wing shift, we agree there is not enough strength for his pins. I am still trying to convince him he can't use a Y cord on the elevons so we are on a learning curve here.

[MUCH LATER THAT SAME EVENING] I ran into radio programming issues and decided to use Y connectors and reverse mount one flap servo. I got twisted 26 ga "litewire" from Servowires.com. Had to order 4 Hextronix HXT 900 from HK, that was $15 with shipping. yawn......

da Rock

The instruction pictures show soldering irons, a roll of servo wire, and some scissors on page 2. Look at the top of that page. What they suggest is actually the best way to deal with getting the servo wires through those wings. If you cut the existing servo lead and solder an adequately long section of wire to the servo, thread that through the wing, and then solder the original end you cut that has the connector, that works well.

If you have a crimper and replacement connectors, that makes an even cleaner job of it. You'll discover that it's worthwhile to have just enough connector/wire hanging out of the wings. Where they can get into the fuselage has restricted room in that area. Wire splices cause a bit of problem when stuffing the wire in where the two elevon servos are and where the back of the LiPo might need to be for balance. The Avia is made to purpose and some things take a backseat.

As for the elevons. No, Y connecting the two servos won't work.

BTW, about the elevon pushrods..........

da Rock

I wasn't thrilled with the extremely fine elevon pushrod wire. It might have been the absolute lightest for the job, but seemed way too flexible for a plane I intend to last for awhile. They seem to have made every choice lean toward 'ultimate contest' construction at the risk of longevity. I've got the contest gliders that competed for me in the 80s. They have the trophies to show they were light enough and nothing has failed or worn out. I'm not sure their pushrod wire isn't so thin it won't cut through their circuitboard horns.

So I up-sized the pushrod wire to something like .037". That's still smaller than I've ever used. I had some plastic tubing it fit with a lot less slop than the OEM wire/tube. I guarantee the extra weight isn't extra weight. In fact, don't plan of your LiPo riding where their pictures show it. Mine is just about as far aft as there is room. Which puts it back where the wing connector wires need room for stowage btw.

The Avia really is a 'serious' glider, at least its design leans that way on everything.

da Rock

Don't know if I've mentioned this, but pay attention to the incidence when attaching the V tail. That single screw wasn't adequate for mine. The fit wasn't 100% solid so I backed the screw up with canopy glue. Turned out I relied on the shape of the saddle and stabs and wound up with some positive incidence. The saddle didn't match the glued together stab shape perfectly. Their fiberglas fuselage is excellent. It is beautiful work, something you'd expect on a full blown, top competition capable tool. But the saddle is just a touch 'generic' and not spending a bit of extra time back there bit me. I eyeballed attaching the tail and have a degree or two of positive incidence. Elevator trim solved it easily, and it's so minor it's not obvious to any but the competitive types.

da Rock

Any of you considering the Avia, it's not a beginner's glider. But it's an awesome weapon. I setup the flaps as recommended, with 3 positions. I'm still adjusting all 3 but that's just tuning them.

The top switch position aligns the flaps with the wing. Obviously that's for hunting. The sucker is FAST at that setting. The middle switch position moves the flap TE 2mm or 5mm (it's not clear from the picture labels) down for "thermik" flight. I expected that to be hard to identify in the air but you can definitely see the bird slow and the few thermals I've encountered so far, there was an obvious benefit. The bottom switch position drops them babies for landing or coming down out of a thermal. They suggest you drop the TE 35mm for "pristani/Landing" for that 3rd position. It definitely slows down.

Like I said, I'm still fiddling around with the top two flap positions. And did I mention that the Avia is fast with the flaps up???

Bobhend

My Feedback: (1)

My buddy is having problems keeping the motor wires off the rotating motor in his Avia. What is the best trick to fix that ?

da Rock

It takes talented hands and some tape. Actually, small hands are all that needed, but the small hands around this house are talented as well.

I noticed that problem when I first slid the motor in to check the fit. One reason I bought the Avia was because I already owned an AXI that was one specification removed from TopModelCZ's suggested motor. Seeing how it fit was one of the first things that triggered my idea they designed the sucker for competition. There is close to not enough room for the wires, right?

You will need some serious tape to hold that wire flat against the inside of the fuselage. And you'll probably need to clean the inside to give the tape a good enough start. Bending the wires to match the contour is required as it will push the tape off the fuselage if there is any memory in the wire that doesn't match the inside contour.

da Rock

I got a question about hinging the Avia and thought it would benefit everyone to hear how my hinging is working.

The manual has pictures that show how to apply hinge tape. My experience with the tape I've used so far has been good and bad. I decided to hinge this high performance bird with what I've had the best luck with on long, very precise hingelines. That would be Ultracote. The pictures in the manual show a 2 step application of tape. That's the same order I ironed on my Ultracote strips.

The surfaces are hinged quite securely with the Ultracote. They don't shift and that's something I've had happen with tape. The Ultracote won't go slack to allow a shift. I'm quite pleased with the tight hinging that resulted.

As for comparing one material to the other, I won't. I'll just say that I know Ultracote hinging works excellently well. It turned out to be easier to do than my last shot at taping long hinge lines like are on this bird.

Bobhend

My Feedback: (1)

Here is my deluxe Hobbyking propulsion system , the KDA22-15M motor and a 25 amp ESC. Net total cost is maybe $30 and shipping is fast and cheap , $4-$10 range. I had a question or two: First, does that canopy retention work ? Second, the V tail retention does not look "robust" I was thinking of making a small 120 degree aluminum spreader plate [a V shaped washer basically] to go under the screw. That and I think you added canopy glue between the V tail and fuselage ? My motor mount was done as follows: filed the aluminum motor mount slightly to fit inside nose. Drilled and tapped the fiberglass mount 4-40 4X, cut out the fiberglass to clear the motor, CA'd the fiberglass to fuse with aluminum motor plate acting as a spacer, mixed JB weld and applied to reverse side of fiberglas ring, installed 4-40 cap screws with 1/8" of threads running into the JB weld before it hardened. I am going to permanently solder the ESC to the motor and use an extension to reach the receiver.

da Rock

The design for the V-tail is it is held down by that one steel screw. The screw goes through a hole into the fuselage. Inside, they provide one small plywood plate that spans the fuselage to support a T-nut for that screw.

The plate etc will be strong enough. It will, however, take some dexterity to get the plate glued in squarely. It might be worthwhile to glue the t-nut into the plate before trying to glue the plate into the rear of the fuselage. You can use the V-tail and screw to hold the plate in the correct location. Keeping the screw clear of glue is a challenge of course.

By their design, the tail is held down by just that screw. There really shouldn't be any major forces on the tail. It's not very large and is very light. However, the screw doesn't really match up to the tail over much area. I didn't trust something as important as the tail being held on by that single screw. If the tail fit into the trough more accurately, there wouldn't be a problem. But the two go together like oil and water. Let the screw get loose and you're in a world of hurt. Expecting the screw to draw the tail down perfectly aligned was a failed hope for me.

OK, I made a couple of triangular filler blocks and glued them to the top of the plate. Took no more than a couple of minutes. They're made out of trash balsa. Will have no real load on them. They're simply to position the plywood plate square. They will support the plate better in the event of a crash, but that's not their purpose. They make gluing the plate into that tiny tube easy. It could be a nightmare trying to get the screw into the plate without getting epoxy on it, trying to hold the plate in the right place and square etc etc. They also will provide a huge amount more gluing area than the plate too. And they helped keep the screw and t-nut clear of epoxy also. With them already glued to the plate, gluing the M shaped piece in, didn't need any epoxy near the screw or t-nut.

da Rock

The canopy retention illustrated by their diagram wouldn't work for me.

I tried to mock up the carbon fiber rod supplied for the task and failed to get it to work as drawn. I frankly couldn't figure out how to get both the front and back ends of that rigid rod to hold the canopy in firm contact. Notice in one of the pictures the rod is kinked? I would bet the original design used piano wire. Wire flexes. CF doesn't. So I cheated. I got the front to work as designed and cut off the rear. One set of rare earth magnets to hold the back on works like gangbusters.

Bobhend

My Feedback: (1)

The project got set aside for a year but now it is going together and I am using your ideas for the V tail and canopy.

I ran into one glue-clogged servo wire passage in one wing & had to cut into the covering. Kit was short 2 horns, other than that, it is really nice quality and design.
What do you use for CAMBER/THERMAL deflection ? I was going to start at 7 degrees. Initial CG will be 71mm. I am inclined to use as light a battery as possible.

I think it may need something to keep the wing from yawing [rotating] on the fuselage. Probably little wood blocks glued to the bottom of each wing at rear.

Bobhend

My Feedback: (1)

Today was the maiden flight and it went exceptionally well with the settings given in the manual. For anyone considering this plane, I highly recommend it. I want to thank DaRock for all his help. First, the maiden flight: the sun was out and I just got it up about 300 ft and shut the motor off and flew until my neck was tired [20 minutes]. Using a 3S 1800 , it still had 4.0 volts/cell . My "deluxe Hobbyking propulsion system" [see above] had perfect power, it pulls 20A with a 10x8 prop. It has a Turnigy 40A ESC [remeber you need one with BRAKE function], and the battery is way back with maybe an inch out into the canopy area. Weight is 36 oz with battery and a WCL of 3.3.. My other plane is a Phoenix 2000, an excellent value, but with a WCL of 5.3 it would have needed a lot of motor to stay in the game today. Now for the details of construction:
I put RTV under the V tail, plus the one screw; I used DaRock's design for the support of the M3 nut for the V tail; I used the stock 0.030" wire and pre-bent it 90 deg, put wires thru elevon horns and bent again to form a "Z". used 6 pcs Hextronix HXT-900 [these are about $ 3.00]; I hold the canopy on with rubber bands, the birds are the only ones that can see it ! I added a balsa cross bar to hold the motor wires away from the motor; I tried RTV but it came off. I programmed a 7 ch receiver so that I could eliminate 2 "Y" cords but really there is enough space for Y cords and the weight is minimal.
I bought the Avia from Espirit Model in Florida, the plane is made by Topmodel in Czechoslovakia. Their instructions are basic and accurate but take some studying. I will probably just leave the servo covers off, and so far I have not figured out how their decal works, but again, birds can't read.

da Rock

The servo covers that came with my Avia did not match my flap servo arrangement. My flaps were on a Y harness so needed identical covers. Topmodel of course supplied 2 pairs of covers. Each pair was for a left and a right. Flaps on a Y needs either two rights or two lefts, or a reversed servo. I made the effort to "remake" one of them to suit because my field can be quite messy and I wished to keep the grass clippings out of the wing, and wanted to shield the horns as well. You're welcome.