Mixing of engine and rudder ?

[appy2day]

Hi All,
I have a 1/4 scale cub with a ST90 engine and would like advice on using a mechanical mixer between engine and rudder. Anyone used this before to add rudder at higher power? Or would I be better of mixing in the computer radio?
Regards,
Paul

[Mike Smart]

Paul,

I would suggest that you are best mixing the rudder with engine manually. There are likely to be varying conditions between take-off and flight where a mix may be inappropriate. I have yet to find a better computer set than the human brain:)

Mike

[jbourke]

Usually this sort of thing is accomplished by setting up the engine with right thrust. It has the same effect but is much easier to set up.

Jim

[appy2day]

Thanks for your input Jim and Mike.

Paul

[Tony Oliver]

If you need it purely to keep take off in a straight line, there's no substitute for manual rudder. As in full size the amount of rudder input varies on how much offset the wind direction is, airflow speed over the surfaces etc.. Full power is being used but the variation in rudder continues so auto-adjustment depending on throttle position will not work.

The only mechanical linkages I know of were in some obscure twins before WW2 when an engine failure automatically put in rudder to compensate.

If you want it to solve varying yaw problems dependant on speed, it would be far better to find the cause and trim it out as already suggested by thrustline adjustments and/or removing warps, misalignments.

Tony