Machining ABS plastic

[cropwell]

Hi,

I have a plastic project box, which is probably ABS. I have tried to cut out for the various panel items (32 switches, for a start), but the cutter (1mm single flute spiral) just keeps gathering melted chips. So I rejigged the Gcode to cut 1 switch at a time, to let me clean the cutter - PITA and my Acrylic coolant (de-ionised water 75% isopropanol 24.5% and a dash of rinse aid) seemed to have no effect.

Now I have changed the design and intend to replace the rather messy front panel with an engraving laminate, so I need to hog out the plastic. That can be a larger cutter. Any suggestions on feeds, speeds, cutter geometry and coolant that might avoid the claggy mess?

Ta folks !

[spluppit]

lower the rpm or increase feed. The problem you are having is heat generation so you need to remove that heat, The main way to do this is by removing a large amount of material that carries the heat away more effectively. You will also travel more distance which spreads the heat rather than concentrating it in a smaller area.

An air blast will obviously help to keep swarf away and help with some cooling but the main cure is feeds and speeds. It's also important to make sure you have no melted plastic residue in the flute of the cutter, if you have new swarf will have a bigger tendency to re stick that that plastic coat as its thee same substrate. Make sure you are removing all the old plastic residue. You are using the right cutter using a single flute, the quality of the cutter can have an effect the better the finish in the flute the less sticking you will get. It's a similar principle to more ductile aluminiums (not gummy, no such material property) Give it a go and see how you get on. I machine a lot of molded abs electrical boxes and its not a problem if you know how to approach it. Many business struggle with abs so its common problem for many, mainly because they try to treat it like a metal.

[cropwell]

Job done with a 2mm 2 flute Straight fluted cutter. cut like a dream at 6,000 rpm feedrate of 900 mm/min 1mm DOC. Then to ice the cake, the cutout piece dropped and caught the cutter. Snap, load next cutter

Cheers,

Rob-T