Cutting plexiglas (PMMA)

How To
21

The only experience I’ve had milling aluminum on the Nomad was some gears using 3 endmills from 2Linc.com
They were diameters of 6mm (19mm long), 4mm (13mm long), and 1.5mm (6mm long).

Others more experienced may want to comment, but fine detail that deep (20mm) I think may be hard to do in aluminum because of the vibration and flex of the end mill if you are trying to use something around 1mm in diameter.

Also, I did use Fusion 360 CAD and CAM to generate the toolpaths because in the case of a 2.5D gear, it was easier to create multiple well-controlled toolpaths using the 6mm to hog out initial material, then 4mm to trim that to finer detail, and then the 1.5mm end mill just to clean up the corners and gear teeth. That type of control on exactly where the tool is going and how fast isn’t something I know how to get meshcam to do.

Warren.

22

@mega128 I am impressed you managed to break the cutters!

I’m with Warba in cautioning against deep cuts with small cutters… you may want to take less aggressive cuts as far as depth-of-cut to decrease overall deflection forces on the tool and prevent further breaks.

As for feed-rates and plunge-rates, generally you want plunge to be 1/4th of your feed with a 2-tooth cutter, so with a 1-tooth cutter you may want to go proportionally slower at 1/8th of feed, just to ensure you don’t bog the cutter down since these aren’t drills with large chip-removal channels… An O-flute cutter may be able to deal with faster plunge though, I don’t know :confused:

23

OK, thanks everyone. I have a fair idea what to order now.