"Steve" wrote in message
...
The linear drive I finally located (haven't purchased yet) is non-marine.
Rather commercial, industrial for gates, wheel chair lifts and positioning
appliactions.

I is presently available from Surplus Center

http://www.surpluscenter.com/item.as...&item= 5-1474

I'm anticipating that I will have to give some attention to marinizing the
unit, but that's what DIYs do.


The other thing you may need is some sort of a clutch to decouple it
whenever the autopilot is not in use.
I know that the raymarine use a sort of a magnetic affair that energises and
locks (by friction) two plates together whenever the autopilot is switched
on.
God knows how you will build that into it!!

garry