Z-Axis Wobble

I’ve got a noticeable issue with my X-Carve 2.0 1Kx1K machine. The Z-axis is constructed correctly and I’ve been trying to remove a wobble that shows up during Z+/Z- movements. Everything from the Z-wheels out “Wobbles”.

No matter how much I play with the eccentrics, it’s either too tight or too loose, but the wobble remains. The Acme screw was recently changed out because the original was bent.

As far as I can tell it has to be the wheels themselves not riding the rail guide correctly. Maybe to much slop, that I can’t even get them to ride clean.

See this video and see for yourself. You can see the router and holder wobble as it makes moves up and down…

Z-Axis Wobble Video

I’ve already contacted support.

Steve Nordahl

What is that clicking noise?
It coincides with the wobble.

I only hear the stepper motor making noise, sort of a pulsing sound. I’m not hearing any clicking.


it might be possible that a v wheel is out of shape. I had this issue with a wheel on the y axis… but it didn’t result with wobble, it just lost contact. But i could see the z running into wobble with a mis-shaped wheel. try spinning the wheels against the rail to see if there is a noticeable odd shaping.

Misaligned thread block and a wheel assembly allowing the axis to wobble?

The wobble coincide with the rotation of the threaded rod, not per revolution of the wheels. That to me indicate that the issue is with the thread block/rod.
How does it behave if you loosen the thread block and let it ride loosely/not seated fully?

its interesting because Z motor makes a loud growling noise when it raises up.
and it cannot get to the limit switch without help with me pushing it.
However, I don’t have the wobbling problem.

MY Z motor

Here is what I would try.

  1. take the router out.
  2. loosen the V-wheels with the eccentric spacers so there is side to side play (V-wheels not touching the makerslide, or at least very loose
  3. loosen the fixed V-wheels
  4. tighten the fixed V-wheels
  5. make sure that the eccentric spacers fit in the mount slots properly.
  6. adjust the eccentric spacers to get smooth up and down motion by hand (should be tight to the makerslide with no perceptible movement when twisted or pressed side to side). V-wheels should not turn if you try to turn them with one finger. Should be able to turn them with two fingers.

Test up and down movement under power without the router. If it’s solid put the router back in. If not, repeat the above steps.


I didn’t mean to hijack Stephen’s thread.
But it kind of sounds like we may have the same problem.

Larry…Whose post are you replying too? Jan’s or mine??? If mine I’ve already done that and there was no change…

To everyone else… Please keep this thread about the Z axis wobble issue only…!!!


What did they say?


My thoughts run to bad V-wheels/bearings or bad makerslide

The Acme screw is running dead straight. I just installed the complete replacement kit for that acme screw 2 weeks ago. The one that came in the kit was really bent and was visable to the naked eye. Today, support has agreed to sending me overnight a complete set of new V-Wheels/Bearings, bolts, spacers, eccentrics, washers, and cap nuts for the Z-axis. The Z-Axis makerslide appears to be good at this time. TBD

I’ll have more information once I install the replacements tomorrow.


Check the pulley on both the motor and the Acme screw to see if there is any slipping. Use thread locker on those little slugs so they do not vibrate out.
This would only cause the z to loose position and prevent it from getting to the limit switch. Your problem sounds like the eccentric nuts are not set correctly. They are a pain as they can ride out of the hole and prevent the rail getting tightened where the v-wheels engage the slide tightly.

In my mind there are two things going on:
1 - V-wheels not tight enough to hold the carriage in place, allowing it to wobble. (symptom)
2 - Delrin block not fully straight relative to the z-axis rod and energize the wobble due to uneven resistance. (cause)

Hope you get it sorted out :slight_smile:

Hi @StephenJ.Nordahl,

I watched your video and can hear a ticking sound when the spindle is moving up that is not really there when it is moving down. From the side view at the 30 second mark, it looks like the pully on top of your lead screw is not flush. This could be part of your wobble issue if the screw is being pushed to the side by the pully.
If the pully on your lead screw is crooked, try removing the spindle, loosening the belting from the motor to the pully, and then loosening the pully on top of the lead screw. Get it to sit flush, then tighten down the nut on top, and then the set screws on the pully. Then put the belt from the motor back on the pully.

Take a picture or video from the side, so all you have is a profile showing the spindle, wheels, lead screw, and Z axis. Check if you have front-back motion, or only the side-side we see in your first video.


EDIT Changed the autocorrect “bully” back to “pully.”

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You said your Acme screw was bent. Did you try to use it? If you did, could you possibly have damaged the little caraige (threaded part that rides the screw) somehow? Maybe the threads got stripped or cross treaded??

As I said above the the original was bent, the Acme screw assembly has already been replaced with a complete changeout.


I def hear a clicking on the way up. It’s hard to see but it does appear that you pully is not straight. Did you replace that as well?

Remove the Dewalt. Lossen the screws holding the lead nut. Is there a space between the lead nut and the router plate? If so, try some shims under the nut.

I think SteveLittlepage is onto something, the thread pulley do wobble in the video.
The clicking sound is very noticable and is more pronounced when lifting vs plunging.

I stand by my initial comment earlier, something (delrin block or thread pulley or a combination) is seeing uneven tension/firmness during rotation - otherwise your Z-axis would not wobble as it does in the video. If it was the wheels alone the clicking frequency would be lot less.
The clicking noise occur several times per revolution of the wheels - but I suspect it “click” once per revolution of the rod?