Official Luthiers Forum!

How do you guys put pickguard material? The few time I've tried it the edges just melt and ball up and it's a total mess.

O-flute bits.

http://www.onsrud.com/xdoc/SuperO = one such bit.

Blessings,

Kevin

ABS is a soft plastic with a low melting point.
SFM for plastics generally ranges between 200 and 500
I believe SFM is lower for ABS than other plastics because of the low melting point.

Your cut is likely too light.
Try decreasing your spindle speed if possible and/or increase your feed rate.

Take more than one pass, you'll almost always melt plastic when trying to go through in one pass unless everything is right. Taking a rough and then finish pass means you only have material on one side of the cutter on pass two, and that means a lot less chips to melt together. When I machine slots or outside profiles in acrylic, for example, I generally run the exact same pass twice and the second one clears out all the welded on chips and other fuzzies.

Correct me if I'm wrong, but I think what Peter means is that your feed is too light, rather than your cut. And he is quite correct on this: you will want to use a feed that seems aggressive. Feed rate would be something like 100 IPM at 10K RPM for a 1/4" cutter, so if you have a 20K spindle then you want to be doing 200 IPM. With a smaller cutter, you still want to be cutting fast, so even for a 1/8" cutter I'd be trying to get up to 120 IPM at 20K or 60 IPM at 10K.

_________________
Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services