I am trying to program a DX6i and bind it to a FMS 1400mm CJ3 Cub. I programmed the TX according to instructions in the manual with the aim of making the Cub easier to fly for a beginner. I made the minimum dual rate 70% for Elev, Rudd and Aiel and set the EXPO at plus 15. I took the Cub out for a test flight and immediately after lifting off from a grass runway it became extremely difficult to control with the result that I crashed and am having to replace the landing gear. I can fly an E-Flite Apprentice set on beginner mode and I can fly a Mini Micro T28 fron Hobby Zone so I thought I could fly the cub at those settings but I was wrong. Please tell me what the Dual Rate and Expo setting s should be in order for me to be able to handle the airplane. Also any other programming I should do to the DX6i ? Thanks

You really can't set your dual rates at a #, the manual should have a measurement like 12 millimeters. Set the # for you dual rate at the measurement that is in the manual, it could be less just because it will depend on where it clevis is on the control horn. As for the expo I use 30% 15% is too little for my taste. Also check your CG point, make sure it was not tail heavy. FMS planes tend to be very scale so most fly that way.

Also check that you are setting your Expo correctly. Novices will sometimes set the Expo with the wrong polarity ( e.g. plus instead of minus or vice-versa ), and they end up with a plane that is far more difficult to control.

I set my EXPO at + 15. I am going back and raise it to + 30 as advised. is + the correct polarity in this situation? I will also look for control surface settings in milimeters. Thanks

I foorgot I made sure CG was correct before I flew it.

for a Spektrum, yes, you should use + expo rates.
personally, I'd recommend not using dual rates at all. you don't want to be fumbling around looking for a dual rate switch while you're flying.
(you mentioned the airplane was 'difficult to control' ... was it difficult as in TOO sensitive? (you just touch the stick and the airplane immediately heads in the commanded direction) or was it difficult to control 'not sensitive enough'? )

edit, you DID check the CG.

yes CG was correct. I didn't have time to determine what was causing the control difficulty. It took off , got about 6 feet off the ground then went into a long turn trying to roll to the right. I managed to get it back down safely but the second flight it hit the ground hard enough to shear off one side of the landing gear. The second take off also went into a sharp turn to the left i think this time. To the best of my knowledge I just had some up elevator and full power on. No aileron or rudder input. the cub took off very fast and very quickly. Maybe I should try less throttle to begin with so it will be traveling slower when it leaves the ground.

I didn't answer your question. I think the controls were much too sensitive. Maybe I accidently had a little aileron input at take off but it couldn't have been much. I may disconnect the ailerons next time and fly it with rudder only and see what happens.

I just realized on your apprentice, you fly it on beginer mode, you may want to put the cub up for a while and concentrate on the apprentice until you can fly on advance mode. But I wouldn't disconect the ailerons, just turn them down, one thing I learned for me was to set the travel for the control surfaces 1.5 the thickness of the surface or 1/4 inch.

Thanks Hawk 131. I have already come to the same conclusion. I repaired the damaged landing gear and hung the Cub back up for a while. I also have a Multiplex Fun Cub that I haven't flown. It has flaps and can take off and land at a very slow speed so I might set the travel way down on the Fun Cub and give it a try on a calm day. I can fly a micro T28 without any problems but I am hand launching it rather than taking it off from the ground and that may be the difference. I accidently set the Apprentice on intermediate one day and almost wrecked it trying to land so I agree with you. I need to back up and get better before I tear everything up.

Sounds like a good plan, like I said FMS makes there scale birds fly like the real things and a cub is not a beginner plane for rc, I have a Carl Goldburg .40 size and it took me about 10 tries to get the take off down pat. Once master the apprentice try the cub, it's a good plane to learn how to use a rudder.