Micro end mills and tolerance - HINT

[etzz]

If you are running Madcam using very small cutters, and you are not getting toolpaths or very short toolpaths, you need to reduce your cutter tolerance. I set tolerance on a 0.005 ball nose to 0.00001 to get a toolpath to appear. Had be stumped for a while.
Eric

[Jason3]

Can I ask what others are using for the tolerance settings in MadCAM?

I've got the tolerance set to 0.005 mm in the Rhino options settings, and the cutter tolerance set to 0.01 mm in the 'select cutter' dialog, but although that makes the mesh very fine it's still clearly visible on curved surfaces after the finishing cut. The finish is very good, but I'm wondering if there's something I'm doing wrong that leaves the mesh visible. I can set the tolerance higher, but it's already taking a long time to calculate the toolpath (2.4 Ghz core 2 duo, 3 Gb ram, Vista OS).

Any suggestions?

Many thanks,

Jason

[JOM]

It is important to reselect the model for madCAM after you have changed the mesh settings in Rhino.

If you use mm, it will make smooth surfaces if the mesh in Rhino is set to 0.01.
The cutter tolerance should also be set to 0.01.
In some cases when using very small cutters (0.3mm to 1mm), the tolerance could be set to 0.005 or less if cutting cavities that are small due to cutter size.

Joakim

[Jason3]

Joakim, thank you very much! I cannot recall whether I did reselect the model on that occasion, perhaps that was the problem.

I found yesterday that my system tolerance under the 'Units' tab was actually set to 0.001 mm, would that account for the long calculation time perhaps? I'll double check all my settings and try again today.

Best regards,

Jason