v-carving help

I’m testing the v3.1.17 development version for its vcarving functionality.

My vcarving bit is as follows:
tip dia: 0
v angle: 90
flute length: .5"
depth per pass: .25"

For scale, the box in the lower left corner is 1/2" square.

The spiral pocket operation generated shows the following;
Cut sequence:
32 cuts of 0.3937 in
and 1 cut of 0.1016 in
The tool may not be able to cut this deep

What am I doing wrong?

In the V carving operation, what is your maximum depth? I guess it is probably 5" which is much deeper than your cutter can cut.

What is your step size set to? It should probably be somewhere in the range 0.001" - 0.010" for your drawing. Looking at the toolpaths it is probably much higher than this.

Note that you need to use a tool other than your V cutter for the pocket. Trying to cut a flat bottom with a 0" tip diameter cutter will take a very long time. In your example you don’t need the pocket operation anyway because your cutter is never reaching maximum depth. The pocket is only needed if you hit max depth in the V carve operation. This is probably a bit confusing so reduce your max depth to something like 0.1" to see what the pocket is supposed to do.

*edited to add
I turned off “make pocket” and changed step size to .01 which helped a great deal.

Is the new and improved

My step size was .25" and my maximum depth was .5"

  • end edit

I must fundamentally misunderstand the implementation.

My understanding of and primary purpose for vcarving is to create signs like this.

No flat at the bottom, and with letter widths chosen such that the cutter won’t plunge through the workpiece.

My secondary purpose is to create halftones; engravings using different-sized circles carved with a v-bit to emulate light and dark areas in photographs.

I searched the help file for “vcarve” but didn’t find anything helpful. Did I miss it?

A step size of 0.25" is way too high. Step size controls accuracy. Decreasing step size improves accuracy but takes longer to calculate and produces bigger g-code files. A maximum depth of .5" is fine. I am not sure why the pocket operation appeared to be set up for 5". I’ll have a play with the code and try to find out what went wrong.

I must fundamentally misunderstand the implementation. My understanding of and primary purpose for vcarving is to create signs like this.

No flat at the bottom, and with letter widths chosen such that the cutter won’t plunge through the workpiece.

That is one way of using it. As long as your characters are narrow enough you don’t need the pocket. However if your shapes are large you may have to leave a flat on the bottom. This is where maximum depth and the pocket operation come in.

I searched the help file for “vcarve” but didn’t find anything helpful. Did I miss it?

No, V carving is too new to be in the help files yet.

I turned off “make pocket” and changed step size to .01 which helped a great deal.

That is much better. If you play around with the detail reduction slider you may improve the S. Decreasing the step size ever further may also help.