Thread: Trim Wheel Idea?
09-22-2009, 01:51 AM #1
Trim Wheel Idea?
I'm designing the C206H Pedestal.
I'm using this tutorial as a guide.
From the looks of the yoke control there is a motorized trim for the elevator.
From the C206H POH..
I'm thinking a small electric motor hooked up to the yoke control could drive the trim wheel if geared. I wanted to add gears to the design so that the wheel has a fine trim on elevator. I'm thinking it's not a direct drive in the cessna.
So a few questions if I may.
1 - Is the trim wheel similar to the flap selector where the wheel sets the position of the trim that a motor then moves the surface too?
2 - Is the trim wheel direct drive? Or does the trim wheel act as a fine tune device (large movement = small surface change) geared down so that the trim moves slowly when wheel is being turned?
3a - Does the autopilot physically move the trim wheel and or the indicator on the pedestal?
3b - When autopilot is disengaged. Does the autopilot...
- Return the trim back to neutral
- Return the trim to the previous position before the autopilot was engaged
- Leave the trim alone (allowing movement of trim by the other two ways)
I'm thinking if the trim is connected to the autopilot then movement is motorized so the selection is done by..
a) Physically moving the trim wheel
b) Pressing the buttons on the yoke (see above)
c) The autopilot making that movement automatically to fine tune the altitude hold.
It's a shame there isn't a electric manual trim control on the yoke for the rudder trim. I know the heavies have such a selection on the yoke to go from elevator to rudder trim. I'm thinking the elevator is more important to trim as it's also tied into the autopilot to maintain altitude.
Some kind of gearing mechanism shouldn't be to hard to figure out and give some resistance to the manual movement of the trim wheel.
Should be cool to make one as it's a control that controls another control that is tied to the aircraft flight. Don't quite know how to connect it to the autopilot though or if that is even possible? To get that happening I would probably need a servo instead an electric motor and a way for that feedback to be sent back to the computer to know where the trim is if I turn the autopilot on
When I started this idea it didn't seem that complex but looks can be deceiving.. I'm determined though hehe
If anyone has such a setup already or other advice would be great as any help would be appreciated.Up Up and away in my beautiful my beautiful - Amphibian
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