Winch speed and torque

[Lester]

I've produced a spreadsheet which should help figure out what kind of winch torque would produce what kind of sheeting speed, at

http://www.onemetre.net/Build/Servo/Servo.htm

Comments welcome!

[Olivier Cohen]

Hi Lester,

Great job, as usual!

Just a word : For an armwinch, you can't do the calculations with a constant radius.

The torque applied to the winch by the sheet line at each position is the line strength x armwinch radius x sin (angle between the arm and the sheet line) x 2 with the block on the arm

That's why with an arm winch it's often hard to sheet in downwind, but you get a "smooth" response when sheeted in, and a great strength.

[Lester]

For an armwinch, you can't do the calculations with a constant radius

Bonjour Olivier

You are right, but I think the very simple calculation is fine to estimate maximum torque required and hence the worst-case sheeting speed.