Not a Laser but HPC CNC - 1mm End Mills

[DavidJHolmes]

Is it possible to cut acrylic with a 1mm end mill? On any setting the acrylic is melting round the mill and then causing it to snap. I've tried alsorts, high RPM with low, medium, high feedrates, low RPM with low, medium, high feedrates. I'm getting a build up a melted plastic which stops cutting and then the bit snaps.

[PhillyDee]

What depth of cut? You need to try and reduce the temperature at the cutting edge, this and a build up of swarf is causing the edge to snap. I have never seen them, but tweakie is the one to ask! My speciality is in metal machining . Plastic is far too soft for me!

[DavidJHolmes]

I was doing three passes at 0.55mm cut. Problem was by the time it was coming round to the final stage of the first pass it would break. I stopped the machine a few times to clean the end but it was gumming up too quick and didn't cut then snapped.

[magman]

Hi,

I think that you'll find that the acrylic you are using is 'Extruded acrylic'
which is a softer acrylic than 'Cast acrylic'
you will find that the heat generated from your cutter will melt the acrylic rather than cut it whatever speed you use.
The melted acrylic, sticks to the cutter and backfills what has just been cut
this stops the cutting of the acrylic , which is why your cutter snaps.
this does not happen with cast acrylic as long as your cutters are sharp

Is the work you need to do so fine that only the 1mm cutter will do ?? a bigger cutter will also help a bit
when we have work that is so fine and precise, we use our laser cutter

extruded acrylic is cheaper than cast acrylic, but by the time you add on all the costs for the snapped cutters.....
cast acrylic maybe the cheaper option in the long run.
95% of the acrylic we cut on our cnc's is 'cast'
if we have to cut extruded acrylic with our cnc'c (because it is too big for our laser)
we use a water soluble oil mist spray to help cool the cutter as it's cutting,
but it does mean there is some wiping clean/dry when you have finished cutting

(be carefull if your machine is not geared up with a mist spray system as water and electricity do not mix)

[DavidJHolmes]

Cheers for that. I did need a 1mm bit to do the work but I've given up. Sticking the 1/8" bits for cutting acrylic so no small jobs. I'll invest in the laser for the small jobs!