PUTTING IT ALL TOGETHER
The axis motors have 3 sets of compound gear arrangements with the final stage consisting of a single gear.
The plastic wheel is the worm wheel which is set up in a compound gear arrangement.
The 25 Teeth of the Worm Wheel are driven by the Worm attached to the motor shaft. (Still need a decent picture of worm profile - assumed double start)
Stage 1 - Compound Gear (Worm Wheel plus gear)
Compound Stage 25/10 Teeth
Stage 2 - Compound Gear
Compound Stage 35/9 Teeth
Stage 3 - Compound Gear
Compound Stage 29/18 Teeth
Stage 4 - Single Gear
Single Stage 37 Teeth
Now we can cascade the gear ratio’s to work out the overall reduction ratio from the input shaft of the motor to the output shaft of the gearbox
Reduction Ratio = 25:2 * 35:10 * 29:9 * 37:18
Reduction Ratio = 938875: 3240
Reduction Ratio = 187775: 648
Reduction Ratio = 289.776: 1 [Input to output shaft relationship]
This means that the Input shaft will rotate 289.776 times for one rotation of the output shaft.
This calculation aligns with those previously calculated in this thread
The encoder coupled to the motor shaft is the ET-MY37 and has a resolution of 7ppr (7 Pulses per revolution) and uses quadrature encoding as per the diagram below
Using both Channel A and Channel B we can actually extract 7*4 = 28ppr because each transition is a distinct place in the signal. Multiplying this by the gearbox reduction ratio of 289.776 gives us a final output shaft resolution 8113.728 pulses per revolution.
Kind Regards Stuart