V bit "outlining"

[Jerry In Maine]

Just cut a project that has letters raised in relief. Used a v care tool path with clearance tool path run first to do most of the work. Clearance path came out as expected, but when the v bit tool path finished I had a faint thin outline around the perimeter of the letters, done by the v bits tip.

I don't know if there was a zero-ing error when I ran the vbit of if something else might have caused it. Project otherwise looks great.

Any ideas as to how I might avoid this in the future?

[Oldmanofgf]

How are you setting your z height. I used to have problem with bit depth when I was setting the z by hand.I now have a touch off probe hooked to the controller computer and ever cut is the same. You don’t have to be off much to see a line between tool changes.
Glenn

[scottp55]

Jerry,
It's important to Z-zero in the same exact spot with both bits...preferably in a spot near the edge(or a clamp) where the material won't shift as much as stress is relieved as you remove material. Either a pencil mark on the material, or writ co-ordinates down, and move to that position before zeroing.
I've found personally, that doing the VCarve toolpath first, gives me less chipout and material movement, THEN do the clearance toolpath.
Maybe give it a try on the next one?
scott

[Jerry In Maine]

I'll give these tips a try. Likely it's just a z-zeroing issue.
Thank you!

[LittleGreyMan]

I've found personally, that doing the VCarve toolpath first, gives me less chipout and material movement, THEN do the clearance toolpath.

This makes sense, especially with wood. That's the difficult part: think of the process, and consider what will physically happen on the machine. If the toolpath are correct, the screen preview will always be perfect, whatever the order of toolpath is. Pixels are not chipout or distorsion sensitive

In the real world, that is not the case and avoiding glitches often requires machining in the right order and sometimes breaking toolpath in several chunks to run the right operation at the right moment in the process.

Scott obviously demonstrated this with a perfect cut without chipout.