McFly settings: how to avoid heat marks?

Use McFly for chessboards. With the settings from CC there are heat marks on the white squares. How to avoid those? I read another post saying the inner cutter blades do not do much more than producing heat. Can they be removed?

And: there are parts of the path that are mirror like smooth, and others are rather rough.

What would be the best stepover for a baby butt smooth surface?

Yes you can remove the inner cutters. I did some surfacing on a maple slab a year ago with one. At first I had the inner cutters on & got consistent burn marking in the surface. With the inner cutters removed, it worked way better.

Having your spindle trammed in is the most important factor for a really smooth surface. Beyond that I think possibly taking material off with the same directional movement can also play a part.

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The feedrate in CC for the McFly is very conservative. Instead of 60ipm, I run at 150IPM, and go up from there. Also, reducing the RPMs can help.

Burning is just “too much friction in one spot”, so anything that reduces that will help. Lower RPMs (less friction) and higher feedrate (don’t stay in that spot).

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I use my McFly to surface stock and inlays (wood and epoxy). I run 200 IPM, 18,000 rpm, and DOC of 0.01" to 0.04" if I’m feeling frisky! I haven’t heard of taking the inner inserts out, but that might have solved some issues I had this weekend. There will be some sanding after, but not too bad with ROS.

Make sure the waste board is level and the spindle is trammed.

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I’m not a user of the McFly but, in general, you can also “burn” the surface if you try to take off too little material. In this case the bit can act act as more of a burnisher.

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