Model V Trim system help

[Bryan]

OK guys I am needing help with the trim system. What have all of you been doing with the allen set screw that holds the trim cable in place at the stab? If I am understanding the plans the set screw that is in the end of the bolt holds the trim cable in, which in turn holds on the castle nut, which attaches the whole thing to the horizontal stab. I am not sure I trust this little set screw to hold this all in place. This small of allen wrench does not allow much tightening. Any suggestions????? Thanks

[n85ae]

If you have the same "long" cable with a coiled spring, that mine had ... I would
figure out a way to put in an electronic sensor with an led display, maybe like
a Ray Allen system. Basically make your own stab position/trim indicator.

The cable system is a pain in the butt, it changes over time as the spring
tension changes. I didn't use the sticker, I just periodically adjust the indicator
with a rag with alchohol, and a sharpee marker. :) This is in turn calibrated
against a red triangle on the slot at the tail. I run the actuator so the tail
is at the red mark. Then verify the indicated position matches.

I will say I used the stock system, and my cable has never slipped though.

Jeff Hays
N85AE, Series 5, IO-240B

[Bryan]

Thanks Jeff, I believe I am going to try a double nut on this. Kind of like what is on throttle linkage at times. The little set screw just is a mess. The allen wrench slips in it and I have not even tightened it down to the point it will grab ahold of the cable.

[n85ae]

Hi -

It'll work, just if I were at that point building a plane knowing what I know now
I'd replace it with a sensor, wires, and an indicator. I've often wanted to change
mine but too much hassle to route wires with the fabric on. :)

That said, the factory system does work. :)

As long as you're back there, you might want to take apart the trim actuator
and clean the commutator, and brushes. Also leave an access so you can get it out later. Those actuators, in several planes I know of were gummy
inside and I know that several had to do that to get the Trim working
well.

I think getting the actuator motor brushes seated will help as well.

I ran my actuator motor at low speed on a bench (removed from the
actuator) for an hour to seat the brushes. Then recleaned, and reinstalled.
Have had not troubles since.

This after I had intermittent trim trouble over several flights til I figured it
out.

Another VERY usefull mod, would be to install a Pulse Width Modulator motor
controller so you can tune the actuator speed. OR you could just put in
a 2-4 Ohm 20W resistor with a bypass switch, so you have a slow/fast
trim selector. The pitch trim in level flight is VERY sensitive with the variable
incidence tail, and you'll spend the afternoon tapping the button trying to find
the sweet spot.

Regards,
Jeff

[Dorsal]

I use a 3.3 ohm, no switch, works well. There are a few nice designs for how to hook up a sensor, I lifted mine from Ken Birchard's build album, also works well.

[hansedj]

http://www.teamkitfox.com/Forums/showthread.php?t=172 here is a link for our ray allen trim indicator did not like the one that came with the kit at all. I think that kitfox might sell a kit now you might want to call and ask.