Inventables Community Forum

Best practice to a perfect depth setting?

Just want to figure out either what I’m doing wrong here, or if something is slightly out of whack on my X-Carve. Here’s what I did:

Took a 1/8" thick piece of wood, measured it with a digital micrometer for thickness, entered all info in the easel software, Zeroed out the X and Y coordinates, set Z to where the spindle was barely touching the wood. Cut a skull out of it.

Took a 1/4" thick piece of wood, measured it with a digital micrometer for thickness, entered all info in the easel software, cut a spot in the wood for the skull to sit in. Zeroed out the X and Y coordinates, set Z to where the spindle was barely touching the wood. Used the measurement from the ‘skull wood’ to set depth of cut in Easel.

Well, it’s about 1/16" too deep. Still looks cool, but this was one of those things I’m measuring before I go crazy with projects - how accurate can I get things. And this isn’t very good IMHO.

Can someone recommend a better way to do this? Or an adjustment to make? Size of item was pretty small too - 2.75" diameter circle with a 2" x 1.5" or so skull in the middle.

Can you measure the amount the Z axis moves if you jog it 1 inch (with spindle off)? Check to be sure it actually moves exactly one inch then repeat the measurement a few time to be sure it works every time. Also do this test with the Z axis moving on different portions of the threaded rod to be sure some parts are not binding and causing it to miss steps.

Also be sure the set screws on the Z motor shaft are tight and the pulley is not slipping (use a sharpie to draw a line across the shaft and the pulley so you can see if it slips any)

When you cut out the first piece, did it cut about 1/32" into the wasteboard? If so, that’s a good indication that you need to calibrate your Z-axis. If you have a dial indicator, you should be able to make a mount to attach it to the tapped M4 holes on the side of the spindle. That will allow you to check how much it’s actually traveling, and let you calibrate the number of steps/mm.

Did you cut both parts on the same spot on your wasteboard? I’ve noticed a .050" height difference in different areas of mine, so that may account for a little bit of error on yours as well.

Beyond that, @AllenMassey’s post has some good ideas about how to check for problems that may cause it to lose steps. They may not help since you went too deep instead of shallow, but it’s worth looking at.

When I need everything to be super-precise on a woodworking project, this is what I’ll do: First, put down some scrap, then make a pocket in it to hold down my workpiece. That way I know that the pocket is 100% level with regards to the router.

Second, I’ll do a surfacing pass on the workpiece once it’s in the pocket, so that I know it’s now an exact thickness, and the top will also be level with regards to the router.

That’s assuming that your machine is dialed-in and giving you repeatable results.

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Appreciate the info everyone. Took some scrap and made a level pocket in it for smaller pieces, for large stuff I’m not really going to worry that much about it. Everything was nice and tight on my X-Carve, it’s just my waste board was off by a fraction on one end and also had a very small (maybe 1/32nd) hump in it. For the size of the board, it’s not horrible.

Pete,

One thing I just learned is it also depends on the BIT size. I ran a project similar to what your talking about. I figured since it was “detailed” I would use at 30* v-Bit. I set the depth of what I wanted, but it was still cutting DEEPER than I needed - the reason is the width of the pass necessary to achieve the cut.

Here is a link to a video on Youtube https://www.youtube.com/watch?v=JGG0yTPih4w&t=1080s that kind of explains it - dry in some areas - but watch what he’s talking about in the “O” section. You will see what may be the problem of using the narrow bit vs a wider bit.

It wasn’t something I hadn’t really paid much attention to until it really counted - and then I had to re do it again… and then again, and then finally looked up the mistake to finally do it the las time LOL…

Basically what it shows is that to obtain the “width” it needs to go deeper with narrow bit.

Hope this helps

Another suggestion for monitoring slippage, you can use “slippage mark paint” which is extensively used by the military. Real easy to see.