X,Y and Z axis stuttering

Hi, just wondering if anyone would know why all three axis stutter when trying to setup the machine in easel? I put the machine together yesterday and last night and this morning x and z were working fine and the right side of y wasn’t keeping up to the left side but now when I run the setup all axis are just stuttering. Any help or advice would be amazing, thanks

DeCator: I had the same problem until I saw that the movement in x and y was set to 1. That’s 1mm per minute, I think, so it seemed like it was just stuttering. As soon as I set the movement to 10, for example, all was fine.

I also had the problem of the y axes not keeping in sync. I re-did the wheel set up and checked the motor wiring, and that solved the issue.

Thanks gwilki for your reply, the movment is set at 10 still stuttering, and the wheels and the wiring have been double checked but in all honesty I don’t know if the left and right y axis are still out of sync since it just stutters and barely moves lol, I know it has to likely be something simple but this is my first CNC machine and I’m just learning and apparently not very well lol

Like you, DeCator, I’m brand new to this. The guys here have been great in addressing my problems, so I’m sure you will get more informed advice than mine.
That said, if you simply measure from the x axis gantry to the ends of the y axes rails, you will know if the x is perpendicular to the y, as least withing a very small margin. If they are out - and mine were - you can just go through the steps of installing the lead screws on the y axes all over again - which I did. I just undid the couplers, removed the lead screws, move the x axis all the way back to the back of the y gantrys, then reinstalled everything. After that, all was well.
Now, clearly, if whatever glitch that got them out of sync in the first place is still there, they will get out of sync again. In my case, adjusting the wheels and making sure the motor wire plugs were all the way seated did the trick. YMMV

Hey guys. Rather than go thru all of the coupler undoing/doing, run the X-axis back until one side is back as far as it goes. Then turn the other ball screw by hand to get it all the way back. The when you power up they will be sync’d.

Sure, take the easy way! :grinning:

I assume that you mean to run the Y all the way back, yes?

Thank you guys for your replies, I have tried them and it’s still stuttering I was just wondering if it could be the power supply, I don’t know if anyone elses power supply does this but everytime I try to jog the machine the green light on the power supply goes out and as soon as it stops trying the green light comes back on which seems to indicate to me it’s loosing power, any thoughts?

I had this happen as well, triple check the the connectors are plugged in properly. I had a couple that I thought were pushed in all the way - unplug them and replug them in all the way till they latch. Then check the motor side .

My Z axis would like rapidly change direction randomly - it was b/c I had bumped the cable a little loose.

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There have been a couple of faulty power supplies appearing in the hand of some customers. If you want Andy or I to call you then send us an email because sometimes the issue is elsewhere. If the stuttering is happening in all axes and the power supply light is flickering then my first guess would be that we should go ahead and ship you a new one.

Thanks Chris, I got a new power supply but haven’t had a chance yet to try it out, I will keep u posted, greatly appreciate your reply, thanks

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Guys easel does that. Its the way the program works. Its nothing wrong with the machine. I thought something was wrong too until I went back to UGS to cut something else and it worked normally. Went back to Easel it stuttered again. Try cutting something in UGS or at least moving the machine around in it first before sending an email. I bet its just the easel program.

Also found both Y axis motors stuttered and one did not keep up with the other. Turned out to be the DC power supply connector and motor connector wiring. While I initialled “tugged” at all wires (together) to ensure secured, I went back and tugged at each individual wire. Three wires popped out. Once secured, CNC ran like a charm


Hey everyone, just wanted to post an update about the issues I was having with the longmill, the new power supply works perfectly and thanks to posts from others about the stuttering of the Y axis it turned out to be a loose wire on the one harness and as soon as I got that back in place it has worked flawlessly. I just wanted to update and say thank you to everyone that replied to my post and everyone in the community that posts and helps people troubleshoot the issues we are having makes me glad to be a part of this community for sure and thanks to Andy and Chris for your replies as well greatly appreciate all the help from everyone :blush: