New trim motor vs old...

[AKJeff]

I have a Kitfox Model 5 Vixen and the trim motor has developed a noise similar to a fork in a garbage disposal. It is time to replace the motor and I purchased a new one from our friends at Kitfox. After installing the new motor I found the downward travel (trim up) went a great deal farther than the original motor and bent some sheet metal and traveled upward (trim down) not as far as the slot in the sheet metal would allow.
How do I adjust the trim? The rod end bearing on the new motor is approximately in the same position (length) as the old one. :( I believe I need to unscrew the rod end bearing to get more length and move the horizontal stabilizer travel up. What is the number of degrees up and down that the horizontal stab is supposed to move? :confused: I'm not the builder and do not have access to the build manual. Any other hints and tips for trim motor rigging will be greatly appreciated.
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[jiott]

Yes, you adjust the rod end up until the down travel just comes to the bottom end of the slot. This gives you maximum nose up, which is what you want. You will still have plenty of nose down.

[jiott]

This is not what the manual says, but many of us with the SS7 have found it to be best. You need all the nose up trim you can get to be able to trim hands off on landing approach with flaps.

[AKJeff]

Excellent. Thank you. Since we're covered in ground fog here in Walla Walla today, I'll go to the hanger and fiddle with the rod end adjustment instead of flying. :D

Do you happen to know the degrees of angle? I'm a geek numbers sort of guy when it comes to that stuff. (Retired Air Force we like numbers...)

[AKJeff]

Thanks for the tip. I adjusted the rod end bearing till I was just able to get a hair (technical term, half-way between a tad and a scosche) from the bottom of the slot.

I wasn't sure about how much thread was still left in the tube, since there are of course no witness holes, and went ahead and removed the rod end bearing from the trim motor assembly. And checked that out and didn't get a warm fuzzy feeling feeling about what I found. Note: The the jam nut is missing for clarity. I'll be looking for a rod end bearing with a little longer threaded section to make me feel better. I guess that's why they call them experimental.

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[jiott]

The rule of thumb is 1.5 diameters of thread engagement gives full strength.

[Mesteve]

The book says it should be set to .5" +- 1/16" from the longitudinal bar at full nose DOWN trim.

[AKJeff]

Thank you Steve.

[AKJeff]

Thank you Jim.