Modify a normal servo to wench servo on RC sail boat.
A RC wench servo required several turns, since GWS died, it's not easy to get one. Thunder tiger also have such servo before, but not any more. My first idea is to use step motor, with limit switch on belt(served to get first ), like the rail system in 3D printer. These ULN2003 + 28BYJ-48 5V is very cheap, but after testing, the torque does not seems promising. The motor is geared, so the holding torque is quite good, but the motor current is quite low, so the turning torque is low, and can be stopped by hand. with SW control with 2 phases engage, is still the same. The multi turn servo has a set of reduction gear on the VR, I came across on web with these toy gear, with 0.5M, I decided to make a reduction gear from out side. I took a metal gear servo, the gear to attached servo horn has a internal M3 threat, I put a very long M3 screw from inside, the the first 15T toy gear is fixed on it. 2nd gear is a 50-10 gear, the the last one(50T) is attached on VR. this give me a 7 tur