Thorp Air Command - T18.net

Does anyone have any ideas of a good way to limit flap travel to 30 degrees with this sort of actuator? There is no limit switch on this motor anywhere. In the up position, it is limited by the travel of the actuator, but I'm trying to think of a good solution for the down limit.

I'm guessing I'll need a mechanical stop somewhere in the linkage, but where is the best place? Any good methods from anyone else's experience?

I attached a larger picture also if it helps.

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Marty G
N50LE
YouTube Channel
martygrosse@yahoo.com

I would think if you used a mechanical stop that the motor would continue to run as long as you had the button pressed, even though it had hit is mechanical stop. That may not be a big issue if you had the top of your flaps marked at 30 degrees so you could see it from the cockpit. Then you would know to stop pressing the flap button and lessen the risk of burning up the motor.

Maybe you could wire in a limit switch, mechanically connected to the bellcrank (or the actuator arm) to shut off the motor when flaps got to 30 degrees.

Ryan,

Thanks for the reply. The flaps are currently marked in that way, I just thought about a runaway switch event that would put them all the way to 40. I may just work up my own limit switch as you suggested.

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Marty G
N50LE
YouTube Channel
martygrosse@yahoo.com

If possible, lengthen the bell crank arm to give thirty when the actuator reaches its limit.

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Bob Highley
N711SH
SN 835
KLAL

If it can’t be rigged to stop at the desired location then use lever or micro switches to cut power where you want it. It would be set up exactly like the trim switches I have seen.

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Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

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