This tip is for GALM users which how to calculate final reduction ratio.

First, you need to calculate primary(Spur Gear, Pinion Gear) and secondary(Diff Pulley, Center Pulley) reduction ratio. For each calculation formula are show on below.

Primary Reduction Ratio

Secondary Reduction Ratio

Let's calculate how is the standard GALM primary and secondary reduction ratio. Here is standard GALM each gear and pulley.

Spur Gear : 92T

Pinion Gear : 23T

Diff Pulley : 39T

Center Pulley : 12T

Primary Reduction Ratio

Secondary Reduction Ratio

Now, you can see each reduction ratio. Then, next is calculation for final reduction ratio.

Primary Reduction Ratio × Secondary Reduction Ratio = Final Reduction Ratio

then this is going to be,

4.00 × 3.25 = 13.00

So, the final reduction ratio is 13.00.

Also, here is calculation when using Gear Drive Set.

Secondary Reduction Ratio for Gear Drive

And here is standard gear drive set ratio (Diff Gear : 54T, Counter Gear 27T).

And the final reduction ratio is,

4.00 × 2.00 = 8.00

Calculation is pretty simple so please make use of your machine setting.