Engraved (carved) letters get concave edges

Mostly Printed CNC - MPCNC Troubleshooting
1

I have been using my Primo for sign making lately. I purchased a carbide engraving/signmakers bit for my router.

However, the letters do not come out exactly square at the edges. The edges of this “n” and “t” should be just 90 degrees - instead the router makes this little concave shape and small rounded points at the ends.

Any suggestions to how I can avoid this? The machine is dead accurate, so I suspect it has something to do with the tool setup.

This didn’t happen with my old V bit, even though it had a blunt point (offset), and this new bit has a sharp point.

Anyone using a similar bit that could share their tool profile, perhaps?

Using Estlcam for gcode and Repetier host for machine control. I use the “carve” function in Estlcam.

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2

One possibility: This behavior is what would happen if the angle on the physical bit was different than what is defined in your CAM. If the angle on the bit is stepper than defined, the bit will pull away from the line as it cuts deeper.

1 Like
3

Thanks, I’ll check the settings, and perhaps try with the tool settings of my old V bit. I’ll also check the physical angle of the bit.

4

It kind of looks like it’s missing the finishing pass.

5

Those corners are always the last thing that happen when carving letters, there isn’t a finishing pass for those.