B-737 rudder trim encoder

[Philb737]

Happy Holidays to all,
I'm looking for a spring to center encoder(MOM) Center (MOM) for the(B-737) rudder trim knob, any ideas?I was able to locate a rotary switch from Mouser electronics part# 690-E3G0603N-2 (http://www.mouser.com/Search/ProductDetail.aspx?qs=Cey2prYh4C8BxqXJ9E1Rkw%3d%3d) , I'm not sure if this is the switch that I'm looking for! :roll:
http://www.mouser.com/Search/Refine.aspx?Ntt=690-E3G0603N-2 (http://www.mouser.com/Search/Refine.aspx?Ntt=690-E3G0603N-2)
Cheers

[Michael Carter]

I don't think that's it. You need a pot, not a switch.

That has two positive stops both sides of center. You need a smooth continuous motion.

[Philb737]

Thanks for the info Michael,
I guess I have to make my own pot:p. I have an old joystick with few 10k pots that I can use to make the (MOM) CTR (MOM) encoder. I'll post my results.

[Michael Carter]

I am not too familiar with the rudder trim on the new NG's. Doesn't it use a trim knob just like the 727?

You can still use a continuous-turn encoder, but I didn't think the rudder trim worked the same way as the elevator trim located on the yoke; momentary up/down.

Once the trim knob is turned it stays there until you turn it back. Same with aileron trim.

I still haven't worked on this in my sim and I even have the gear ruduction on the real trim knobs. So much to do and so little time. :roll:

[Philb737]

The old B737 had the cable and pulley mechanism, but the NG B737 trim knob works just like the Alirons trim with a switch.

[Michael Carter]

I see. Then it uses a similar momentary set-up just like the elevator trim switch?

I guess you had the right switch after all. Sorry.

[Jackpilot]

Phil

The one to use is a rotary, spring loaded to make it return to center, with two momentary positions left and right of center.
I managed to get two (Janco )
ref 79-2257 9617.
I can probably spare one but they were not exactly cheap! PM me.

[Jackpilot]

Here it is: about one inch max diameter. Aviation grade.

[Philb737]

Thx Jack,
Check your PM!:D