CNC cutting two different heights !HELP!

Hey there!

I have been trying to cut foam molds for a composite layup and have been running into some issues.
When I run the rough cut it gets rid of most of the material. However when I start the finishing cut its runs fine at the beginning, but half way into the cut its seems like the bit is higher and is no longer cutting the material away.

I am using an STL file to import the 3D model. I do not change the bit ( Just because the one I am using leaves a fine enough surface for my application). So i am not sure why its losing height when It is cutting. Any thoughts or tips? Feel free to ask question. I am trying to learn!!

Update: I have also attached some pictures to indicate my problems. A little more background. I essentially took a model of something and split it because the overall length of was took long to cut as whole part. It seems that the issue happen at the same spot on both cuts ( the centerline of the CAD file). I am not sure if that is significant or not to solving the issue. Just thought I’d note.

Can you share the file or project? The images are difficult to determine the issue since the foam is very monotone in color and taken top-down.

The fact that this is happening down the centerline of the project on both pieces is probably more than a little significant. If there is an issue, it will probably be with the file or its interpretation unless this exact issue occurs on every other piece that is placed in the exact physical location on the machine.


Brandon Parker

Hello Brandon,

Thank you for replying. I should note that this started to occur randomly. I have cut the same files about a month ago with no issues. Only changes was I had to change the homing switch for the z-axis. Also in the picture, if you notice there is a “rough” side and a “smooth side”. However that was a picture of the part after a completed cut, which baffled me. I cannot upload the file unfortunately. Also, would you recommend any other software than easel to use with the X-Carve?

Considering the three phrases you said above, why are you running a finishing pass? The finishing pass in Easel is meant for utilizing a smaller bit to get into places where a roughing bit cannot. It is not meant as a “spring pass” … Performing a Roughing and Finishing pass on the same piece with the same bit is frivolous, especially in foam. If you just want a “spring pass” performed on the part, you can just run the operation again with a Depth of Cut set to the max depth to be carved on the workpiece.

With respect the these sentences, you did home the machine and zero the Z-Axis prior to starting the cut correct?

As for the machine losing height halfway through, it could be several issues. Is this a regular X-Carve? Have you ensured everything on the Z-Axis is tight? Are all electrical connections tight? Is the bed of your machine coplanar to the travel of the X & Y axis (i.e. flattened the wasteboard with the machine itself)?

It’s not like you are putting any pressure on the machine cutting the foam, so you should not be losing steps in that regard.

For software, there are plenty of options out there and everyone has an opinion. For design, you can use whatever you would like that can output either GRBL compatible GCODE or a file format that can be converted to GCODE. For GCODE sender programs, the same applies; it just needs to be compatible with GRBL and many options exist there as well.

If you can’t upload the file, can you upload the GCODE or screen capture of what Easel is showing in the preview? I am just curious if anything changed in EASEL’s interpretation of the file and thus has changed the toolpaths between your carving adventures.


Brandon R. Parker

Hello Brandon,

Thank you for your reply!

I guess I am a little bit confused now. How is it that when I do a rough cut and finish cut, the surface finish is different even when i use the same bit.

With respect the these sentences, you did home the machine and zero the Z-Axis prior to starting the cut correct? Yes I did home the device.

Is this a regular X-Carve? Yes this is a regular X-carve with the upgrade kit (X,Y,Z stiffeners) from easel.

I cant upload the finishing G-code because the file is too large.

settings.txt (271 Bytes)

If you change the step-over, that makes a difference. I was not thinking about that part…

From what you have posted, I do not see anything that is obviously wrong. If you want, you can PM me and I’ll give you my email address to send larger files to. I can then see it live on my end and possibly carve it out as well.

The only thing that I think might be causing an issue (at the moment) is if you are in fact using a flat endmill and the direction of the toolpaths is causing steps. 3D contours are best carved with bits that are rounded on the tip…ball-nose endmill or tapered ball-nose endmills…IMO


Brandon R. Parker

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