I’d like to know also.

Using the planetary stage reduction formula (R/S) + 1 for each stage, where R is the number of teeth in the ring gear and S in the number of teeth on the sun gear, and counting the teeth as follows:

First stage S = 21, R = 59, second stage S = 13, R = 59, output stage S = 13, R =59,

I get motor stage reduction = 3.8095:1, second stage reduction = 5.5385:1, output stage reduction = 5.5385:1, so the overall reduction is the product of these, or 116.855:1, which agrees closely with the published figure 117:1. The published free speed is 81 +/- 7 RPM

Veselin, did you remove the first stage and replace the motor pinion with a 13 tooth one made from the first stage planet carrier? In that case you’d get overall reduction 30.675:1 for a new free speed of about 310 RPM.

Or did you remove the second stage, giving a new overall reduction of 21.099:1 for a new free speed of about 450 RPM?

Will someone please check my analysis above?