Shuddering x carriage - No movement

Long storey short: I got my x carve in the summer, got it all set up and mostly tuned but ultimately burnt myself out on the project. Everything was running and moving just fine, though I was having some issues from incorrect motor current, to low. Over Christmas I started getting back into this and upgraded to a dewalt spindle.

I fired the machine up and went to adjust the current, Y axis moved just fine, but the x carriage just shuttered on the axis. I nudged the current up but no change. I checked the wheel adjustment and everything was fine, just able to spin the wheels. It still just shuddered. Turned everything off and the carriage moved smoothly and easily. I could feel the toothed wheel spinning when moving. Belt tension is tight.

I loosened all the wheels off so they spun freely, just in case I had things to tight. Fired it back up, tried again, no change. I’m stumped.

I had a similar issue with the Z, but it would move maybe 0.1" when told to move 1". But that worked itself out after bumping up the current a bit.

BTW, I have the 1000cm with nematodes 23s. I’ve attached a video showing it… which I’ll upload later when I get back to my desktop.

Check pulley set screws.

dumb question but are the motors wire opposite of each other? so one is spinning in the opposite direction to the other?

I just had a very similar experience with my x axis. In the middle of a cut it just stopped (by the way I run my machine pretty much daily) I then tried to move it using the controls in easel and it just shuddered and sounded horrible and barely moved if at all. I checked the usual wheels and belts and pulleys bit, then based on a recommendation from Inventables I switch the y and x wires at the g shield to see if it was isolated to the x motor. With the wires switched the x moved perfectly and the y was jerky. Bad g shield. The replacement seemed to take care of that issue, but I am now having new ones. Looks like another call into Inventables tomorrow. Oh, the joys of having an x-carve!

Video is here …

Ignore the fact that I was surprised that the Z axis worked. I Forgot that I’d tweeked the current for it.

Video is shot while the v wheels are loose, but it behaves the exact same with the wheels snug.

@ErikJenkins It’s funny you mentioned that, because I had my hand on the pulley as I was moving the carriage by hand, to see if it would turn, and I didn’t think to check the set screws.

@GlennCoates My issue is on the single x carriage motor, not the 2 Y axis motors, but thank you.

@JosephCompton I hope it’s not an issue with the shield. Does the movement look similar to what yours was doing? I’ll try swapping the wires tomorrow if it’s not the pulley set screws, which at this point I’m hoping it is, would make like so much easier if it were.

Yeah, Jeff, that’s pretty much the same sound and disfunction. Changing the wiring on the g-shield really isn’t that difficult and would tell you a lot. Good luck!

Ok, so I swapped the X and Y cables tonight, and … It seems worse. I turned it on and told it to move, and it did a time or two in both directions, then instead of moving 1", it moved probably less then 0.25" a time or two, and then just stopped all together.

Definitely not what I was expecting.

I took a video after it stopped. I could hear some electrical noise coming from the machine as well after it stopped. You can kind of hear it in the video around 0:22 - 0:24 and then again at 0:32, it wasnt a constant noise but pulsed on for a moment or two, and then off.

I had the same issue and found that one of the wires from that axis had been pulled out of the connection at the GRBL shield. Double check your wiring where it connects to the GRBL and insure that they are in the correct order and secure. Solved my problem.

Best of luck,


Got it fixed!

Thanks all for the help/suggestions.

Took a bit to figure it out. I think originally I had a wire loose/poor contact that I didn’t notice.

After my first problem I’d forgotten that I started messing with the trim pots for the current and had turned them up a bit. Well, it turned out I’d turned them up more then I had thought and forgotten about them. So that when I swapped the x and y axis, I eliminated the loose/poor connection, but was then sending enough current to the motors to stall them, forgetting that I’d been messing with the pots.I’d spent for what feels like forever going over every connection trying to find something wrong, only to randomly remember the pots when I almost put my hand onto the controller. I turned them down, and everything worked perfect, just with the x and y swapped.

Now to adjust the current.

Thanks all again.