Cutting Acrylic

[Britannicus1]

I'm looking to cut out shapes from Acrylic and also to engrave some text on the shapes -

I have a simple 25 degree engraving point - 1/8th inch diameter and a 1 mm flat milling tool with my CNC when it arrived, would these be adequate for the job?? - what speeds and feeds should I look at to prevent melting ?

My CNC is a fairly basic generic 3020 which I got from ebay - but comes with little advice or recomendations

Should I order different bits - which would be good bits to get

cheers

[ngwagwa]

I engrave with a 30 degree cabide tool at 22000RPM and 300mm/min and for cutting I use a 2mm tool 2000RPM and (of the top of my head) 300mm/min.

[cropwell]

Hi,

Especially with small cutters, you need to cut fast enough to avoid rubbing and have open architecture end mills (like the one for ali - room for the chips to fly out). Single flute seem to work OK.

The pattern was done with a 10deg 0.2mm engraver DOC 0.2 total depth 0.5mm speed 12,000rpm feed 10mm/sec 66% stepover. I use a spray bottle with 75% deionised water 25% isopropanol and a splash of dishwasher rinse aid to kill surface tension. Lettering was done with a 90deg 4 flute V cutter, similar speeds and feeds, but with a more DOC as the bit is stronger. My general rule of thumb for acrylic and wood is DOC = diameter of cutter.


Infill is Humbrol enamel.

Hope this helps.

I am thinking of making a 'wet bench' so I can pump my cutting fluid over it and recover and re-use it. I will post results if I do it.

Cheers,

Rob

[ngwagwa]

This is the sort of stuff I have been engraving

[cropwell]

If you can, always get cast perspex, the extruded is a different formula with a softer structure and can gum up cutters more readily.