At 01:24 PM 3/24/2013, you wrote: >If you built the horizontal stab per plans to be only 5/8" thick, >I'm not sure if the MAC servo will fit inside either h/s or >elevator. It'll be a tight fit, for sure. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
My horizontal stab and elevator are built to plans and the Ray Allen trim motor is mounted in the elevator, right next to the elevator spar. The very short run from the motor to the tab is very rigid with zero movement in the trail edge of the tab. A quick look at the Ray Allen site indicates the servo is 1 inch thick. I measured the elevator spar and it is right at 1 3/4 inches thick. I had removed the original setup with cables that are indicated in the plans because I didn't like the slop in the system. My indicator quit working after just a few flight hours but I've never bothered to replace it. The final approach trim setting seems to work just fine for departure also. Anyway, you don't trim to a setting on an indicator, you trim to eliminate control pressure so who needs an indicator anyway. As I recall, I hogged out some foam and glued a small piece of ply to the foam for the base, then used short small screws to mount the servo. Don't over build the assembly as the forces are not that great. The hinge in the plans, tube in a tube, is very light and works well. Just make sure the epoxy used to mount the stationary tube doesn't get inside the movable tube. Don't ask me how I know. Just start over and try it again. :-) Something like Vaseline on the end of the moveable tube might work. I made a quick trip to the airport and took a few photos but couldn't get them to down size under 100K so if anyone wants some photos, e-mail me off net at flesner at frontier.com or if someone wants to post them I'll e-mail them to you. Thanks.......... Be advised, If you mount the unit in the elevator, or any movable surface, it may / will effect control surface balance and could change flutter characteristics. In my case my elevator is balanced. Larry Flesner
