Administrators Rich 26 Posted March 23, 2012 Administrators Share Posted March 23, 2012 Hey guys Got a big puzzle here with the Multiplex Easyglider Pro... Set it all up, tested EVERYTHNIG, and it all worked perfectly, tested on full power, all fine, range tested it, perfect again, everything doing exactly as it should, but, soon as it was launched, it wanted to roll heavily to the left. Full Right stick stopped it from completely tipping over, so I did a left, left, left and landed it... Tested it all again on the ground, everything working as it should. This is also not a new build, its a used model, previously flown exactly as-is, same motor/esc/prop etc, I changed nothing at all. I did set airbrakes in my 10CG, to 1 switch, but that had no affect on its normal operation when tested.. For the life of me, I cant figure out why it rolled to the left so heavily, and it happened again when Leon tried it, only with kamikaze outcome of a busted fuse where it rolled right over and became a lawn dart on the second attempt. Anybody ever experienced something like this with a glider (1.8m span) as I cant think of, or find anything that caused it to roll so violently, nor could Leon... Both a bit puzzled I will likely glue it back together and possibly try again, but fear the exact same thing will happen again.. I should add to, it left the hands straight and level, not thrown up at an angle Link to post Share on other sites
arun 0 Posted March 23, 2012 Share Posted March 23, 2012 Caveat - I'm speculating below, but maybe it will help... What motor/prop have you got in it - recommended setup or something hotter? The roll could be a result of torque in which case, go gently on the throttle during launch. I've seen this same effect in a few flying wings I built where you had to ease them into flight on low throttle. Only other thing I can think of is if one of the winglets has got bent and is at a significantly different angle to the other. But seems unlikely if you and Leon gave it a thorough check... You could go back to basics with a piece of string and measure the distance from each wing tip to same point on rudder etc. and make sure everything is perfectly square. A really "out there" explanation is that the wing is not centred on the fuse and therefore one side is producing more lift than the other causing the roll... Link to post Share on other sites
Administrators Rich 26 Posted March 24, 2012 Author Administrators Share Posted March 24, 2012 Hi Arun Indeed, Dave reckons it may well be torque roll, which I still cant figure how such a big model with a little motor could manage, but I guess anything is possible... Hopefully will have it glued back together to try it Sunday... Will bring a black bag with it too, just in case.. Link to post Share on other sites
arun 0 Posted March 24, 2012 Share Posted March 24, 2012 Try putting your ESC into 'soft start' if it isn't already. It may be the motor is coming on very suddenly which is 'jerking' the model into the roll. On a side note, since I know you have kit that supports this, I've found a throttle curve helps a lot with electric throttle response: A good starting point is (0,0)%, (25, 50)%, (100,100)%. E.g. 50% power at 25 % throttle and linear between that point will be OK -- however, using a curve like this while giving you nicer more linear throttle will mean even smaller application of throttle stick to stop the torque roll inducing since small movements early in the throw will have a bigger effect. Link to post Share on other sites
Administrators Rich 26 Posted March 25, 2012 Author Administrators Share Posted March 25, 2012 Cheers Arun, oddly enough, it seems to already have a steady throttle curve by default on all models, for every plane... Throttle seems linear on all models, and always has been on my radio I've got it all fixed now, busted rudder servo replaced, fuse sort of straightened out best as possible and glued back together in about 8 places, but had to put a lot of washers into the motor mount to get it out of extreme left thrust.. Upon refitting the canopy, its now about half an inch too long on the front, so the squashed foam factor is now visible when you put the canopy on... Ready to go now, so will try it again today, only this time, half throttle on take off like Dave advised Link to post Share on other sites
arun 0 Posted March 25, 2012 Share Posted March 25, 2012 I believe all brushless ESCs would have some concept of a "curve" built in - so probably for your ESC that curve is a good match with your particular motor. I think the main argument I can see for using the Rx curve is that you can tweak the shape of the curve in a way you can't on the ESC. This definitely falls in the fine-tuning category well after the model is trimmed nicely Link to post Share on other sites
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