Z-Axis works with "Test Motors/Encoders" but not with manual movement

Problems with the z-axis when I’m manually jogging but when I use the “Test Motors/Encoders” it moves fine.

I’ve set the “z-axis steps per revolution” to 700.8 per the link where I bought it.

I’ve checked my cable with an ohm meter and it checks good.

I’ve ensured the wiring is correct multiple times. The hall effect sensor 5V and Ground are in the correct pins per the spec of the motor and my board.


The video shows me hitting the “Test Motors/Encoders” first which works, then I hit the manual jog on the Z-axis which makes a noise and I can see the z-axis motor quiver/trying but doesn’t turn. What am I missing?

notes: When I hit “Test Motors/Encoders”, sometimes I get a fail on the right or left motor but never the z-axis. You might notice that in the video, a lot of times I get a full pass on everything.

Windows 10 HP
Firmware 1.20
Ground Control 1.23

Each of the two encoder channels put out 16 purses per rev of the motor, and we use both the rising and falling edge of each pulse of both channels. So we see 16 x 4 edges per rotation of the motor. Try using 16 x 4 x 43.8 = 2803.2 for the ‘steps per revolution’, let us know if that helps.


Good news: that worked
Bad news: Stall Torque: 18kg.cm isn’t enough when the going gets tough. It’s rated at a whopping 6.5A stall current for 12V but I believe I need a higher gear ratio.

It stalls trying to overcome the bind on the Rigid router on the way down. I’ve tried numerous bungies.

Anyone got a link to a Z-axis motor that’s not sold out? I don’t need the whole Maslow z-axis kit just the motor.

I’ve bought motors from these folks. Theirs are 64 ppr (16 x 4) as well.

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@blurfl I’m thinking the 70:1. Do you recall which one you bought and your thoughts on it’s torque and speed balance?


I bought the 131:1 but it seems a poor match for the Ridgid mechanism which wasn’t designed for high speed motions. The one you mentioned would probably be better.

@blurfl I bought the 70:1 motor.

The page says the following " 64 counts per revolution of the motor shaft, which corresponds to 4480 counts per revolution of the gearbox’s output shaft" but I’m not sure if Ground Control should see this differently. What should be my GC Steps Per Revolution? Thanks.


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Try 4480 steps per rev. we found on the main motors that the gear ratio was not
exactly what they said and so had to tweak the result.

David Lang