Toolpaths and Z-Axis Issue on Walnut Valet Tray Project

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1

Hi everyone,

I’m working on my first 3D cut and could use some advice. I’m making a 5.5"x11" walnut valet tray for my sister’s birthday (tomorrow, 10/10/25), and I’m running into a couple of issues.

1. Roughing Pass Problem:
For the roughing pass, I used a Jenny Bowl Cut Bit. The pass depth was set to 0.125" in the Tool Database, but the pass cut over 0.5" at the center of the tray. The bit was howling loudly, and I was worried it might snap. I dialed back the feed rate, which helped, but I’d like to set multiple passes for the roughing instead of one deep cut. I’m not sure how to configure that in the 3D toolpath settings.

2. Finishing Pass Z-Axis Issue:
After roughing, I swapped to a 0.25" ballnose endmill for the finish. I reset my Z and previewed the run; everything looked correct. However, when I start the cut in gSender, the Z axis suddenly shoots straight up, hits the Z limit switch, and the operation stops. I’ve tried creating different toolpaths, resetting XYZ positions, but nothing seems to fix this.
It feels like a setting or setup mistake, but I’m not sure what I’m missing. I noticed that there’s a separate 3D Roughing and Finishing toolpath option—I used the 3D Finishing for both roughing and finishing so that the toolpaths are “connected”. Could this be causing the problem?

Additional Note:
I know I could run the entire job using the 0.25" ballnose endmill for the entire process, but that would take over an hour. Using the Jenny Bowl Cut bit cuts the runtime in half, which is important since I’m making two of these trays (twins).

Any guidance on how to set proper multiple passes, troubleshoot the Z axis issue, or just do this in an entirely different way that gets that job done would be greatly appreciated. Thanks in advance!

Tray Image
Tray Image1082Ă—494 29.6 KB

5.5x11x0.9 - Updated Toolpaths.crv (2.8 MB)

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@Tpoole1988 I looked at the file quickly. You have already guessed what some of the problem is. You have not run a 3D roughing toolpath at all. You have set up two 3D finishing toolpaths. In VCarve, the finishing toolpath overrides the Pass Depth setting in your tool database. A finishing tool path will always go full depth in one pass. Ouch!
You need to set a 3D roughing toolpath. That will take passes according to the pass depth that you have set for that tool. In that pass, leave a small amount for the finishing toolpath to remove - say .02". Then create the finishing toolpath. It will remove the .02" in one pass.
It looks like you have set a stepover of 18% for your roughing bit. I would increase that to 40%. You are going to remove any ridges that leaves with your finishing toolpath. Set the stepover of your finishing bit to 8%. It slows things down, but you get a very nice finish.
Also, speed it up. You don’t say what machine you are running, but since you will only be removing .02" of material at 8% stepover, you can easily run this at 120ipm, even on a Long Mill.
Finally, for your cutout, you have no tabs, so I don’t know how you are holding the final piece down. Increase your ramps. 1/8" is too short to make any difference. Go with 3/4" minimum.