gboulton
Posts: 1862
Joined: 5/28/2005
From: La Vergne,
TN, USA
Status: offline
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Well, since the wheel pants arrived, I was motivated to go out to the shop and look over the damage from Sunday's maiden. Here's the full scoop:
1) Need a new set of axles...hopefully one I won't cut off IN the flat spot this time. *heh*
2) Gear will need remounting. No problem, but going to put a 1/8" light ply doubler on the fuse this time, and tie the mounting plate in to that, as well as F2/F3.
3) Found that the LE bottom wing mount, while still intact, was going to go pretty soon...TE mount already had at one side. So, fuse will get 1/8" light ply doublers around the wing saddle as well, and wing mounts will be redone to tie into those.
4) Prop i, of course, shattered. New one will be on the way from Bob's Hobbies soon.
5) Spinner took a minor ding to the paint...no physical damage however, so a quick touch up will be fine there.
6) Flying wires are fine...just apparently either THOUGHT I put Loctite on the turnbuckles and didn't, or the Loctite wasn't enough. In either case, replaced the turnbuckles, and will CA them next time, which should hold them, but still allow them to be "broken loose" if needed.
Obviously, none of those things are big deals...in fact, no more than a day's work for the lot.
The one truly disappointing thing is that there's a TREMENDOUS amount of slop in the elevator halves now. I'm having a great deal of trouble tracking it down, but at least SOME of it is in the HiTec 5645MG servos back there. it also looks like some of it may actually be in the linkage, despite the use of VERY high quality components, including Titanium pro links, Dubro Ball Links, and the Dubro 866 Heavy Duty Control Horn rigs. I am, frankly, kinda disgusted with this problem, as i specifically went with those components to AVOID any slop.
In any event, I've put a couple of JR 8611's on order, figuring I might as well just bite the bullet, and will be redoing the linkage from servo to surface. Will keep the ball links on the servo side, and look for a way to go to ball links on the surface side as well, and eliminate as many 'connections" as possible.
Finally, the more I think about it, the more I think that the airplane IS a bit tail heavy, despite my original assessment that it wasn't. Initially, it wanted to climb a bit on me...few clicks of down righted that no problem. However, it would pitch up rather significantly whenever power was cut, and was quite sensitive in pitch on the landing approaches, but not during normal flight.
I had originally thought there was some down thrust in the engine, despite my attempts to set it 0-0. That would certainly explain the pitch up when power was cut. However, so would tail-heaviness. the pitch sensitivity is probably explained by the fact that I had MASSIVE expo in the elevator, and had trimmed some down elevator...during cruise flight, those two factors would combine to make it less sensitive in pitch, but as power was reduced and speed fell, the down trim would be less effective, and the longer elevator movement required would have pushed out of the "expo zone" so to speak...
That being the case, as part of the repairs, I'm going to remount some equipment. Smoke pump, its battery, and the Rx batt were all about 6" behind the CG. Since the gear are off, and the tank area easily accessible ANYway, I'm going to go against my initial thinking, and go ahead and move all of that equipment up into the tank area, directly under the CG. The tank tray will be remounted higher in the fuse, so the new "smoke/batt/servo" tray can go below them, with a safe couple of inches between the two. Next, the choke and throttle servo, which are currently about 18" rear of the CG, will come up there as well...figuring that since I have a bunch of radio components up there ANYway, might as well put as many up there as I can. Finally, I'll probably move the motor another 1/4" out. All of these things combined should make at least a "notable" difference....and it wasn't IMPOSSIBLE to land before, just difficult.
So...there you have it.
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The free man will ask neither what his country can do for him nor what he can do for his country. - Milton Friedman
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RE: Jim LeRoy Pitts Bulldog - Scratch Buil... - 
