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Extreme Flight Owners Thread

ryan_m

100cc
I finally maidened my MXS this evening, IN THE RAIN. wasn't none too pleased with the way it handled. Im hope'n that it was the servos. as far as just flying around it was OK. but harrier was a freakin hand full, as was landing and im pretty spot on when it comes to landing. to keep a straight harrier I had to give around 3/4 left stick, my other planes jump a bump of right stick. even at that it was very squirrely, unstable and unpredictable. I was flying nose heavy as I do on all maidens and first 15 flights or so. there is some play on the control surfaces when I try to move them by hand. elevator at center had no play but toward end of throws each way there was quite abit of play. ailerons seem to have alil at center. im gonna get some new servos and try them out. I really hope that's the problem.

the only other 3d I really tried was to hover and a few rollers. hover was pretty easy but I didn't have to be on the sticks all that much. rollers pretty much sucked but I usually have to get used to and really dial in the plane before mine look decent on those. did try a couple elevators but even with extreme throws they didn't drop too much like they should have. idk just hope'n its the servos. kinda sucks, wish my noobular self had somebody I could go to
First off - if you have play in the control surfaces you have a problem. Either worn servo gears, bad servos, loose screws in your linkages, something. That's purely a setup problem and will definitely make the plane fly worse.
Next - if you are really nose heavy lots of things will be harder. Harriers for one. And elevators won't drop vertically at all. Get closer to a neutral CG and your elevator will drop much more vertically.
 

wedoitall

Member
i was just a tad nose heavy, but i do think i have some servo problems. im trying to upload some pics now. i checked out the measurements on the stab and it looks good, but i did notice a small gap between the firewall and the balsa thats behind that on the fuse(dont know what the exact name is). dont know if this would cause a thrust issue or not.


View attachment 8819View attachment 8820
 
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skibum44

70cc twin V2
The servo problem isn't going to be the reason behind the 3/4 left stick. That gap will throw off your thrust but it appears that it would need right rudder, however if you trim at 3/4 throttle it may negate that effect at lower throttle settings. If you can't get that gab back in and glued, you should be able to offset with some washers. There is a check sheet I will try to round up and post.
 

Cmala

70cc twin V2
I don't understand 6, 7, and 10. Is there a throttle cut in there somewhere?

Also, I wonder how trimming per 8 and 9 would affect KE flight?
 

Steve_B

70cc twin V2
I read somewhere he is using a 24x10 because he is still breaking it in.

'Back in the day' if you were breaking a (glow) motor is the usual drill was to use a slightly larger than optimal prop in order to keep the RPM down. It's kinda the opposite to electric. On electric large props put more stress on the motor because they pull more amps but on i.c. as a general rule larger props hold RPM and power down and so put less stress on the engine.

Maybe the thinking is different these days with gas engines?
 
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wedoitall

Member
The servo problem isn't going to be the reason behind the 3/4 left stick. That gap will throw off your thrust but it appears that it would need right rudder, however if you trim at 3/4 throttle it may negate that effect at lower throttle settings. If you can't get that gab back in and glued, you should be able to offset with some washers. There is a check sheet I will try to round up and post.
what i was kinda thinking about the thrust because that is pushing it back to the left alil . but i do wanna try and fix it and worse case correct it.

when i trimmed the plane out yesterday i had to give quite abit of right trim to get it to fly straight and level. i did trim at 3/4 throttle but i dont think i gave and rudder trim at all. but i didnt do any down or upline test. I need to try and fly again this evening. Ive only got to fly it once and that was late late yesterday evening, was getting hard to see.

ah, thank you thank you. i just printed and lamenated that, it will stay in my radio box.
 

Steve_B

70cc twin V2
Cross trimming between rudder and aileron can also cause some strange handling. As a first pass visually check that the rudder is lined up dead straight, adjust if necessary. In flight you can check for cross trimming by setting the plane up to fly dead straight then roll inverted.
  • If when inverted it turns right then add a touch of left aileron and a little right rudder trim
  • If when inverted it turns left then add a touch of right aileron and a little left rudder trim

Keep adjusting until it flies straight both upright and inverted. Also check lateral balance (one wing heavier than other), though it would have to me miles out in lateral balance to make any significant difference.
 
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