I managed to make several different tiller drivers. I used windshield wiper motors and winch
arrangement, ballscrews and lead screws. You could probably use two or even 4 windshield wiper motors in parallel to get much more power in a winch arrangement, or possibly drive a ball screw using one of these motors and get an incredible amount of torque. Typical stainless ball screws use 440 grade which does rust much more easily.
If you have a wind vane
for when the wind
picks up, the motor
does not need nearly as much speed or force to be effective in light wind
, so I would imagine using a single
with ball screw would be cheap
and effective drive for you.
Your concern of prop wash on the wind vane
oar only verifies that you have an inefficient drive system. Propellors if they be used at all should be much larger than this, or 4-5 feet in diameter in your case turning slower than 100 rpm
. Moving a small stream of water
very fast is inefficient and wasteful. There is a reason my sculling oar is 16ft long on 27ft boat, and a regular paddle is much less efficient.
I would suggest you use the sails
. If you disagree it is likely you need to try a little harder to catch the wind. I found this always works and it's possible to sail everywhere. I often watch people motoring when I am sailing going the same speed, but when they see me and try to sail, they fall behind and start the motor again because they just didn't set the sails
correctly. The concept
of motoring for extended periods is a poor one.