Can you put a mark on the inside of the housing that lines up with something on the movable plate and rotate the plate by hand until it stops. You should be able to use pi*(d/2) to figure out the degrees.
John, thank you for the help. I took the formula, substituted "x" for the asterisk and solved for "x". I will admit that I am rusty on my ritmetic but in transposing the formula here is what I came up with. (Pi) (x) (d/2) = 1
1 / (Pi) (d/2) = x If I imagine a 4" circle just for discussion,
1/ (3.14) 2 = x
1/ 6.28 = x
.1592 inches = x So, .1592" = 1 degree of rotation. And .1592" is almost 1/6 of an inch.
Seems to me that .1592" is going to be hard to measure. But if my calculation is correct it does give me a second checking method.
Did I get the ritmetic right? Thank you for your help.