Z Axis Going Wild

I am currently carving a sign for a customer and my X-Carve is cutting depths all over the place as it executes the design. I would liken the finished appearance to the Grand Canyon with certain random sections gouged almost all the way through my material and others barely scraping the surface.

The X and Y axis appear to be working properly overall with only minor areas of sloppiness. Can I attribute this to the fact that the Z Axis is taking on such a thick section of material at a time?

The the drill bit is securely in the router, screws on the Z axis are tightened and the wiring looks and feels secure.

Any ideas to solve this would be helpful.

Something is slipping. Either the belt is loose, the set screws are loose(causing the pulley to slip), the router isn’t secure(causing it to slide up and down as it goes), the bit isn’t securely locked in the router. The amount of unevenness side to side once it gets down into the pocket makes me think it’s the router, bit, or gantry…if it was the z-axis itself the insane depth disparities should stay consistent with the path it is supposed to be taking

Thanks, I’ve already checked a few of those but I’ll try going through that full list and post an update.

Try physically lifting the z axis up and down and see if there is any slop.
On mine the nut at the very top of the lead screw was loose and needed a really good tightening.

Also check the set srews in the Z pulley.

The problem lies with your wheels on the Y axis. They’re too loose causing the Z-axis and entire X-axis gantry to twist (lift). Tighten up the eccentric wheels on the side plates of the Y-axis; it’ll solve this problem.

@Traxxtar I’m interested to know how you are so sure this is the issue based on the information provided, please elaborate.

Who are you directing this question to?

@MarkA.Bachman it was in reply to @Traxxtar, i have edited the post

As the Z-axis descends and plunges into the material, it produces a rotational force on the X-axis due to the fact that the bit/router extends in front of the gantry a few inches. If your Y-axis wheels are loose, you can see the deflection in the Z-axis as it will allow the gantry to rotate/twist. It’s ever so slight, but can cause the exact problems you’re seeing.

That makes sense but is there no other way that this can happen, e.g. if the lead screw nut is loose (this happened to me and had a similar side effect)?

I had the same issue and found that the wires in the motor were loose. check your plug

This seemed to make a huge difference to the depth issue. Thank you!

Now the only issue that seems to still be there is that when I cut a square the sides are perfectly straight, but the bottom and top lines are at a slight angle resulting in more of a parallelogram than a square.

The depth issue seemed to be solved though so at least that’s a step in the right direction!

Every time you power up your machine you need to make sure that the X and Y axes are square.

To do this, I have 2 equal sized blocks that I place at the left and right sides of the machine between the front Y risers and the X-axis makerslide. I put these in place and pull the x-axis toward the blocks. These blocks should be the same size if your machine is square. You can check for square at this point by using a square between the X and Y. While holding the X-axis power up the machine. This will make the machine start up in a consistent state as close to square as you can make it.

This consistency is really important for multiple tool carves (even if it isn’t perfectly square).

Good luck

Precision 3-2-1 blocks are perfect for this.