Problem with centring on Atlas DS095 FMD.

[andyharrold]

Please excuse my lack of knowledge but this is my first mouldie. I have recently bought an F3F airframe secondhand.I am pleased with my buy, but have run into a minor problem whilst setting up the model on my FF8 transmitter.With a fresh model memory being used on the tx,  the left aileron, Ch 7 is not centring correctly. In order to get to a position where both ailerons are flush with the wing I am having to use full subtrim on Ch7, opposite subtrim on the other aileron and almost full aileron trim! Not ideal.Having removed the servo covers I can see that the two servo arms are symmetrically rigged WHEN the ailerons are level. The servos are epoxied into the wing.I have tried 3 types of tx module/rx.  35Meg Futaba, FrSky 2.4 and FrSky 2.4 Telemetry. All identical. My options as I see it:It may be possible to rig up a tool,( space is tight) to enable me to slacken the servo arm, rotate it one spline , and retighten with the servo still installed.I guess i could remove the servo, and do the same as above. I buy,steal, borrow a usb servo programmer. I have looked at the manual on the hyperion website, not sure it likes windows 7.Buy a new servo. Any thoughts? Have I missed something obvious! Many thanks,  andy h

[Andy_B]

make up a tool to unscrew the servo screw and recentre the servo arm ......................going to be alot less hassle .....try cutting down an allen key and just grind flat onto the end of it ................

[satinet]

it doesn't sound like the servo is not centring properly. That would be if it kept moving to a different position.Ask the person who you bought it off what type of TX they are using.

[Feefo]

If you reset all your sub trims to neutral, what position are the servo arms then? Is 1 pointing to the trailing edge and 1 pointing to the leading edge of the wings (i.e. 1 aileron up and 1 down) or do both ailerons point up (or down)? If both ailerons are up or down I think you need to either adjust the control rods accordingly (ailerons up needs shorter rods, down needs longer) or make some new ones if there's not enough room for adjustment. Or I may be drunk.....

Edited September 4, 2011 by Feefo

[Jerry Lunt]

Your OP reads to me like you know what you need to do  i.e., take off the servo arms, set trims to neutral and replace the arms on correct splines.  Ensure all lengths are equal and trim as necessary.If you cain't get the arms off 'cos there's too little room, you may need to spring the servo off.  Easiest way I found is with a rightangle flat blade screwdriver positioned under the output shaft and lever gently against the wing skin.  Good to grind off any excess epoxy up the side of the servo first if you can. HTH.  Jerry

[andyharrold]

Tom, Sorry if I confused you. When I said problems with centring, I meant problems with the centre point.I did speak to previous owner, he had no problems, was not using Futaba. Feefo,  rod lengths are fine.with all trims at zero, one arm is at 10 degrees toward TE and aileron is flush. the other is at 90 deg and the aileron is up by 5mm. andy, thanks, i will try the cut down allan key. That was my preferred option. cheers, andy h

[Andrewmawr]

A thought occured to me while reading this thread Andy,if the screw is steel,it might be wise to attach a small magnet to the allen key,this would magnetise it and minimise the risk of losing the allen screw inside the wing.Might save you some hassle

[satinet]

It's not confusing. what I am saying is that the problem probably lies with the previous owner using a different type of TX which has different servo centres. It could well be that the only answer is to reposition the servo horns. Unless there is some other programming issue on the radio.

[andyharrold]

Problem sorted. Thanks for everyones input. It was  decided that one spline on the servo would be too much in the opposite direction so I have just lengthened the rod to zero the aileron so i am no longer requiring subtrim.