pitch trim indicator

[skonie]

I have searched the archives and have not come up with anything yet so i thought I would ask. Has anyone made a different pitch trim indicating system as yet? I am not a huge fan of the coil spring and the cable as if the cable binds there goes any trim. All I think would be neccessary is a proximity switch that turns on a green light on my panel to tell me the trim is set for takeoff. Anyone have anything like this installed?

I hate to have to reinvent the wheel if someone ahead of me already has and can tell me where to get parts etc.

Thanks

[jtpitkin06]

Read my post of 5 days ago. Pictures included.

http://www.teamkitfox.com/Forums/showthread.php?t=2580


John Pitkin
Greenville, TX

[kitfox2009]

Hello Skonie
I find on my Vixen that I never use the cockpit trim indicator. I have an arrow indicator on the root of the vertical stabilizer that shows "take off trim position" and on my pre-flight inspection that gets checked. The Vixen has a jack screw that adjusts the fixed portion of the elevator so it is easy to visually inspect. The "in-flight" adjustments are so small, I doubt if any gauge would be accurate enough to be reliable. Just my thoughts.

Don Hudgeon

Vixen 912UL IVO IFA.

[jtpitkin06]

My $25 trim position indicator system moves full scale when the stab moves from full up to full down. It is sensitive enough to register stab movement of 1/8 inch. The scissor link has almost zero lash. Repeatability is highly accurate.

Because the trim motor is a bit fast for my taste I am wiring up a pulse width modulated speed reduction to add to the trim motor circuit. That should make the trim a bit less sensitive in cruise and still give near full torque to the trim motor. (If one were to add a resistor to simply drop the voltage, the motor would lose too much power.)

I agree you should have a reference stripe on the stab/fuselage to compare with the gauge on preflight. Once the gauge is deemed accurate, you can reset the trim for takeoff using the gauge when you do full stop landings and depart again.



John Pitkin
Greenville, TX

[kitfox2009]

Hi John

Good idea on slowing down the pitch speed. In cruise I can barely touch the switch without going too far the other way. Let us know how it works.

Don

[Dorsal]

I used a 3.3 ohm resistor and it works great. I also use the trim indicator on the dynon which I find helpful.

[hansedj]

http://www.teamkitfox.com/Forums/showthread.php?t=172 Here is a thread on pitch trim