Posts: 209
Joined: 9/10/2003 From: Mount Joy,
PA, USA Status: offline
I use four Hitec HS-85MG's in the wing, two standard servos for rudder and tow release. For ailerons/breaks, I use Z-bends for the servo side and the threaded side for the control surfaces. I replaced the steel push rod for the rudder with a carbon rod to save nose weight. For the elevator, I use a Futaba S3150 together with a servo frame. The servo is attached to the frame with screws. In case I need to replace the servo, it is an easy fix:-)
The connection between the elevator and stab could have been better on my Discus. I had a lot of slop. I used some plywood, sanded it, and epoxied it into the gap between the inner side of the rudder and the aluminum part where the elevator is attached to. There is still a little slop but I can live with that - considering what I have paid for. For the linkage, I used a fully threaded rod. After adjusting it, I glued one end to the clevis using CA. Here are some simple instructions in case you did not see these yet: http://www.amdhobby.com/images/discus.jpeg
< Message edited by joedoe -- 12/30/2007 5:02:12 AM >
Thanks. the control throw and CG as per instruction worked well? My stabilator had a lot of play as well in all directions. Needed to shim it with teflon tape to reduce the play. The video is fantastic to say the least. Hope my bird is as good. Will post video.
Maiden the plane this morning. The 80 mm cg was too far back for my likings, A little twichy first flight, also the condition wasnt ideal. Landed a little had. Moved cg to 77mm, second flight was much nicer. Because of the weight, it was a little slow though. Second flight was a revelation. Went further than I ever dared before with my 2.6 meters. This bird really poses an out of range possibility
It was fun, however the weather deteriorated, landed nicely, pack up and went home. Will try again tommorow. For the price, I think this deal is almost too good to be true. I have 3 japanese made scale gliders, they are a little better made (not much) but cost 2 times it price and half its size with 5 times the work required,( need to build the wings up). The only dissapointment with the plane is the swivelling saddle for the stabilator, has way too much play in it. I had to shim it with teflon tape before it was acceptable. I would recommend that the unit be stripped and modified to carry a needle bearing assembly for effective and accurate control.
At the rate the chinese are improving, we will be seeing european standard kit soon. The best thing with the kit are the wings, even though the coverings are a little sub standard, but they are well made..a little too well, they almost dont flex, giving a "V" look as oppose to a "U" look. The blue canopy tint looks good in the air, The rudder is very effective so is the stabilator. The aileron seem a little sluggish though particularly on approach when speed is slow.
There you have it. A quick and almost instant gratification project that is easy on the pocket and gets everybody talking and wondering at the same time....it is a big bird, not the biggest but certainly stands its ground. Good platform to start flying bird gliders before ordering from ICARE or Tun Modelbau...
Posts: 1
Joined: 6/19/2005 From: Lampasas, TX, USA Status: offline
Hey guys, I am getting ready to order this plane myself, it is just too good to pass up. I was wondering if anyone has given this bird an electric drive yet and if so what you used .
Posts: 268
Joined: 6/3/2003 From: SIMPSONVILLE, SC, USA Status: offline
There is quite a few thread entries on the powered installations. I'm in the end stages of electrifying mine. I am using a 5505 motor with an 80 amp esc. don't know the battery configuration yet. stuffing this motor in it presented a real challenge. the more popular way is to use a motor with a planetary gear drive so it can be mounted further back and a smalled cann, can be used.
Posts: 174
Joined: 5/12/2004 From: Little Rock (via London Eng.),
AR, USA Status: offline
A flying buddy told me a friend of his has one of these planes NIB and wants to sell it because it's too much plane for him. He's looking for $150. I am interested, but concerned about the wing "pop" mentioned earlier. The other odd's and end's that require re-fits are not so troubling, but a wing re-do is an issue, I think. Anyone else had wing problems?
Keith
< Message edited by kwmtrubrit -- 1/8/2008 8:09:06 PM >
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I just had one of those wing pop. I had mind on the grd when we were trying to see how much the wings can flex. after that mysterious sound that was obviously something breaking internally, I dismantle the wing and found later that I could not get the joiner into the wing again. Further investigation, we found no. 3 or no. 2 rib has fail and blocking the joiner from reaching the further structural section that takes the load. That rib is balsa and the first few ribs are non load bearing. We concluded, when the wings flexes, the root section gets the most flexing, due to the geometry and non structure member of first few ribs, they pop.
Been flying it since with no further problem. The wings are built very stiff, as such they dont flex much to relieve stress, all the stress seem to concentrate at the root.
Unlikely I think, because the failure is cause by the wing flexing against the wing joiner. I think its no big deal, its just a case of misdesign, as it is not a load bearing structure, it is of no consequence. (hope I dont find out I am wrong the hard way.) I have yet to pull excessice G, no loops yet. If it passes the loop test, it should be fine, Loaded it to 3 Gs on grd, seems all OK.
I have since strip the stabilator saddle apart and modified it to carry 2 sets of ball bearing. I found the hole on the saddle pivot was drilled oversize, as
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RE: 157" Discus Glider - 
