Reduction ratio about os-arm HOT 3 CLOSED

Because my harmonic drive is designed different than the standard, the formula above needs slight modification.

The number of teeth in my "flex spline" is irrelevant, instead what matters is the number of teeth on the input (circle spline equivalent) vs output (flex spline equivalent) sides of the housing. So the formula would be (68 - 70) / 68, which gives a reduction of 34:1. Note this equation results in a negative number, which means the output spins the opposite direction of the input.

from os-arm.

I would also need this information.
I tried to calculate it myself with the steps per rev and i got 1:29 but in testing it didn't quite work out.

from os-arm.

Looking at wiki You should see that the ratio is

or For example, if there are 202 teeth on the circular spline and 200 on the flex spline, the reduction ratio is (200 − 202)/200 = −0.01

from os-arm.