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Elevator Trim Servo Wire/Jackshaft Interference Issue?

Greetings All!
Drawing 4, which details installation of the electric trim servo shows routing the trim servo wiring through the snapbushing in the elevator with a note to position wires so they don't interfere with the servo jackshaft. The servo jack shaft will extend into the snap bushing through it's normal travel.
This looks pretty lame as inevetibly the jack screw will rub against the servo wires and that's not cool! :eek:
Anybody else notice this? Did anyone route their wiring differently to avoid this? :confused:
 
Interference Issue Solved

I did drill another hole. slightly above the existing hole for the wires. Itworks great! I get a little uneasy drilling holes in a structural member to resolve an issue. I would have thought Vans would have corrected this by now. It's obvious the plane was designed for manual elevator trim. The electric trim was not thought out as well.
It's always good to get other peoples thoughts for some assurance. It also helps others to see a problem that can be created if you follow the plans blindly. Thanks!
 
I drilled a second hole for the servo wires too, it's an obvious and easy improvement.

Ted, as you build the airplane you'll find that the over all design is pretty good, but a lot of little details like this were not thought out well. Van's doesn't seem interested in fixing things like this even when it's pointed out to them. Their usual answer is "just build it per plans". Now that's pretty lame if you ask me. But fortunately, a lot of these things can be fixed very easily by us, so just go ahead and fix em. And consulting the group is always good (usually more useful than consulting Van's). Chances are others have noticed the same problems and have found good solutions.
 
Instead of drilling you can also run the wires through the relief at the inboard part of the elevator rib. The relief is in the corner. Its a little tunnel that comes out onto the elevator shaft that you riveted to the elevator spar. Its a little tunnel waiting to be used for those wires. Unfortunately it is not exactly round. Instead of a grommet you'll have to get creative. Proseal works great. Clean the area around the relief, run the wires through, jam some proseal around the wires and the relief, tape the wires down..and let it set. It will not come loose! From there you can run it along the tube. You can secure it to the tube by different means but a nice fillet of proseal works great if you prep it. We do this with instrumentation on test aircraft. We're always looking for a way to get stuff like this done without drilling. It sounds a bit strange, but it is a preferred method where clamping cannot be done.
By doing it this way you will not have any wire flopping around chafing against anything. You can always drill another hole. Thats acceptable...and you will need to in many other areas anyway.

Drilling is just as good. Make sure you back it up with a grommet. Bring the bundle as close to the pivot point of the elevator as possible before coming off and heading up to the connection point. This point will be near the center of your horizontal. This keeps it from making large sweeps as your elevator moves.

John
http://experimentalrv7.com
 
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