Uneven pocket depth

I’m using Easel to mill a pocket to hold a 2 x 3" single-sided PCB in place. I’ve got the X and Y dimensions coming out right, but the bottom of the pocket (Z depth) is uneven. The right side of the pocket is always just slightly higher than the left side (by ~0.5mm–left side is perfect), which is enough to screw up my traces. This issue is consistent across multiple materials so I’m sure it’s not a problem with the depth of the material itself. I’m thinking the X-Carve is out of whack somewhere but I’m not sure where that problem lies.

So my questions are:

  • What might be causing an uneven Z depth? My Z axis is level (if that matters) and my table/material is flat.
  • How can I ensure that I get an even Z depth when carving pockets?

Thanks for any help!

Here’s what comes to mind for me:

  1. If it’s carving from left to right, maybe the collet is slightly loose and the bit is being pushed up inside.
  2. The right side of the table is lower than the left OR the X and/or Y axes are being pushed up slightly as the X-carriage reaches midspan. If you haven’t fortified the X and Y axes, this could be a definite possibility, especially going from the left to the middle. It could also be the reverse is true, the X and/or Y axes are bowing down slightly from spindle weight, going from middle to right.

What modifications have you made to your X-Carve, and how do you know your table and material are flat?

For what it is worth I had a similar issue when trying to do shallow pockets in coasters… I found that my spoil board was sagging in the middle by up to 1.5mm in places. I shim’d it in places and sorted the issue out mostly. I think evenly I will use a planer bit to flatten the properly.

Simon

Thank you both for the ideas. It seems my Y rails are slightly uneven between the left and right side. I’ll try some adjustments today. FWIW, I haven’t done any mods to the X-Carve (pretty much brand new with about 6 hrs. mileage) and I used a level to check that the work area/material was even, though I’m sure there’s a more accurate tool for that type of measurement.

If you have a dial indicator, you can make a jig to hold it in the M4 holes on the side of the spindle. Then just ride front to back and left to right enough to identify your low spots. It’ll also give you an idea how much flex you have in your system just from pressing on the various axes.

Where is a good place to start troubleshooting uneven Z depth? I also am having issues and would like to read up before asking for specific help.

I am trying to cut out large parts on my 1000x1000 that half of the part is not cutting the full depth of material and the other half is fine.

I would make sure your wasteboard is level to your spindle. I would take a small piece of scrap, move the spindle to the area where it was pocketing to the full depth, place the piece of scrap under the spindle and lower the spindle until the bit just touches the wood (don’t have the spindle on, you can actually do this with the entire machine powered down). Then without adjusting the height of the spindle, move it to where it wasn’t pocketing and place the scrap underneath it again, and I imagine you’ll see a gap.

You can try to shim your wasteboard to get it square, or you can just buy a spoil board cutter (make sure it’s shank size fits in your spindle), and just run it over the wasteboard to level it for you.

Thank you @PJTX for your response. @Gumcontrol I hope you got your Z sorted and I am not intruding on your thread…but didn’t think starting a new thread was needed.

I recorded a quick video of my very crude measuring. Towards the center of the waste board and far right side…it is actually less depth there meaning it should be cutting deeper by .5 - 1mm (eyeballed) in those areas.

HOWEVER, at the end is a photo of a long rectangle I cut out. Near the center of the waste board it left about 1-1.5mm of material in the final profile cut but cut out the part entirely towards the bottom of the screen. I am perplexed as this is opposite what I was expecting to find.

Now what?

Thanks!!!


I have been using Aspire and Chilipeppr. So I decided to do a test cut of a rectangle in Easel and into my wasteboard for visual reference and experienced the same results. Before this cut I did bump up the Z axis Pot just a little bit. I am unsure how far I can turn it. The difference in depth seems like it may be a little less…but still unacceptable.

Photo below is my waste board. The rectangle in the center of the board was my latest cut from Easel showing the bit did not go through part of the material.