Roll Trim Servo install Q

[Gyrodoug]

I'm curious about installing a Ray Allen roll trim servo to replace the manual one with spring tension.

How hard is this process? Pros/Cons?

Thanks!

[Raymo]

I helped my hangar neighbor upgrade his RV-7 recently. Not a simple job but not difficult either. Primary reason for upgrade was to have auto-trim tied to the AP. We're also going to replace his old stick grips with Infinity grips for additional buttons/functionality.

Assuming RV-6 as in your profile:
You'll need the roll trim kit from Vans for your plane and a trim relay.

Drilling the mount holes required a 90° drill and associated drill bit sizes (#28 for #6 mount screws) and step drill for snap bushing installation for wires to pass through the side of the center section seat support. If the pitch rod needs to be disconnected for access (likely) you want a special tool for reinstalling the shim washers on each side of the rod end.

[Jpm757]

I have the manual aileron trim and rarely use it. Most autopilots don't really need aileron trim as the control pressures are so light.

[Raymo]

Originally Posted by Jpm757

I have the manual aileron trim and rarely use it. Most autopilots don't really need aileron trim as the control pressures are so light.

I rarely use aileron trim but my AP almost always does to compensate for cross winds. YMMV

[Gyrodoug]

Originally Posted by Raymo

I helped my hangar neighbor upgrade his RV-7 recently. Not a simple job but not difficult either. Primary reason for upgrade was to have auto-trim tied to the AP. We're also going to replace his old stick grips with Infinity grips for additional buttons/functionality.

Assuming RV-6 as in your profile:
You'll need the roll trim kit from Vans for your plane and a trim relay.

Drilling the mount holes required a 90? drill and associated drill bit sizes (#28 for #6 mount screws) and step drill for snap bushing installation for wires to pass through the side of the center section seat support. If the pitch rod needs to be disconnected for access (likely) you want a special tool for reinstalling the shim washers on each side of the rod end.

Thank you! This is the sort of info I was hoping for. I'm interested in roll trim when stick flying, no so much when the autopilot is flying.

I'm not much of a builder - hence the question in the first place

Thank you.

[airguy]

For normal flight it's really not needed - at least not electric for sure. For those with fuel outboard of the normal main wing tanks, either extended leading edges or tip tanks, it becomes a lot more desirable. Burning fuel from farther out on the wing makes a big difference in producing a heavy wing on the other side and 2-3 gallons imbalance is noticeable.

I have 15.5 gallons in each outboard wing leading edge, and when flying with fuel out there I don't need my Dynon Skyview reminder to "switch tanks" at 5-gallon intervals where I have it set - because the roll trim callouts will be coming from the autopilot long before then. If you are running the AP control module with integral auto-trim, this could be problematic because if you are not paying attention to it the machine may run full trim to the stop one direction unless you are switching tanks earlier than usual.

Gotta be at least 10% smarter than the device which you are attempting to operate...

[Jpm757]

If you keep it simple and go with the manual aileron trim, JD Air makes a nice trim wheel to replace the stock lever.
[Screenshot-20200415-153548.jpg](https://postimg.cc/BXY9hqcc)