Motor control problems?

My package arrived in Chicago yesterday!!! (Order #5648). While waiting for the kit I have been playing with Easel and building some files. My shop is 200 miles away, and we are not going there for a few days, so now I am setting up the electronics & Z Axis, installing the firmware, and messing around with ground control.

Running the “Test Motors - Encoders” routine, all is good, each motor smoothly doing a cycle in both directions.

Playing with the Z axis control, the Z Axis motor turns, but, while not turning, the Left Chain Motor “throbs” and vibrates… wouldn’t seem like that motor should be getting any kind of signal.

Playing with the Sled Movements, Left or Right right jogs cause both chain motors to rotate to the left or right in sync, but again, the left motor throbs while turning. Up and Down, both chain motors rotate in opposite directions like expected, still with the left motor throbbing.

So, I switched the wires to the chain motors, and the throbbing moved the the other motor, making me think that at least the motors are OK.

Is there a problem with the Left Chain Motor control, or is this “throbbing” normal? I suspect that if the motors were mounted to the frame this throbbing/vibration might not be noticed.

Am I overthinking this?


Welcome to our group. What version of the Software and firmware are you on?

This is not as odd as it sounds at first. The Motor controller chip for Z and one side is shared. I know there was some change in what internal clock was used to address this. The version will possibly change the noise I don’t think it has been eliminated.

Thank you

Ground Control V 1.09, Firmware v 1.09

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To be clear, I am pretty happy that everything seems to have loaded and installed correctly. One of my main concerns was having to fight with the Firmware/Software installation, as this area is not a strong point for me.

Thanks for your quick response… I am relieved that this stuff is working to spec.


Based on the conversation it sounds like it is working. There still could be issues not uncover. Seeing it move on the frame is the proof in the pudding.

I’m here to help. I’m happy to help. I collect a lot of information and over time it becomes useful works I write up. We normally release updates Bi-Weekly. V1.10 will be out this coming Wednesday.

I have a Website dedicated to helping improve the Maslow communities experiences over at:

Accounts are free. It helps if you set up an account there we end up with information to support you better.

If you want to try v 1.10 early it’s available over here:


Calibration Issue

I also have a wiki with some “cliff notes” here:

Thank you

What you are seeing is the motors are tuned to expect the weight of the sled and so they are really twitchy without the sled there. The PID tuneing expects to see more resistance so they are overcompensating.

I’ve noticed that the left motor seems to do it more too, but I’m not sure why. It’s on my list of things to dig into, but it doesn’t seem to be causing problems so it’s not on the top of the list. It probably has to do with which pins are used.

Basically that sounds normal, but I’m glad to hear you see it more on the left too because that’s what I see also


Thanks Team!

I will hopefully be up and cutting by Easter, and will have a follow up then.

Bee, I will sign up on DisciplesofCNC tonight. I will do the Firmware update on Wednesday.


I am glad that you experienced the throbbing or pulsating too! I was calibrating my chain and both sprokets would pulse back and forth. I get decent movement out of the five degree adjustements, but not the one degree adjustments. There is also alot of nose with just the chain on the motor. Isn’t it reasonable to have PID tune values be different for the chain only calibration movements? I think that calibration would be necessary for each object that is made on the Maslow.

Could you possibly find a way to reduce the motor torque needed to turn the sprocket and allow it to be turned by hand? I am not sure that I would volunteer, I am more of a maker of other’s designs instead of a coder or designer.

Turning it by hand is a really cool idea. I had a test setup at one point where you could move the router around the sheet by hand which was fun. The controller just gave the motors enough torque to overcome the weight of the sled.

If you wanted to open an issue for that idea it would be more than welcome. I probably won’t mess with it until we get everything super stable. It seems like every time we add a new feature we get a new bug also


not possible, it’s not motor torque, it’s the 291:1 gear ratio and the worm
drive that prevent you from turning the gear by hand.

A dual shaft motor would allow for manual adjusting, but you’d still need 291 turns per sprocket revolution.

It’s a feature, not a bug, and herps the router from moving and losing position when it’s not under power. That’s any time it’s not moving since these are brushed DC motors rather than steppers.