Machining acrylic

[rgollar]

Could some one please give some suggestion on a speed and feeds (sfm) and chip load per tooth on a two fluted endmill for machining acrylic. I have never machined acrylic before, so does it chip real easy during machining? Thanks in advance for the input.

[Henk]

Alu-Tools with an coating

Speeds and feeds like Alu

Coolant On

[Goldorak]

it was long time ago

 

if my memory is good , low rpm and medium feed and lot of coolant

 

acrylic will melt if it's too fast n and break if it's too slow !!

[gavetta]

Try sfm 400-600 with sharp carbide and a chip load of .006 for say a 1/4in cutter. Smaller cutter, smaller chip load.

And yes it will chip. HTH

 

edit: yeah and what the other guys say about melting and using coolant too.

[jeff]

Yes definitely use coolant.

And if the part doesn't have a high tolerance, you can use a torch with a slow flame to "polish" it also...works like a charm.

[dgriffiths]

Check out Onsrud. They have some "O" Flute solid carbide single flute cutters that work great on both FF and GP Acrylic. I second the flame polishing of the edges if your tolerances will allow it. I have also used some downward spiral flute cutters in the past with success. Just make sure there is somewhere for the chips to go under the part. HTH.

[Tom Dorgan from American Precision]

Depending on thickness, I use Onsrud 63-724 O flute at 175IPM @ 24000 RPM for 1/4" or thinner. Much faster and you get a dime finish on the edge.

[Thee Dragracer1951]

I've also had to use HSS cutters as they are generaly sharper.

Yes it will chip

[Snaglpuss]

I second the motion for Onsrud carbide "O" flute bits.

We dry cut lots of acrylic on a router. Peck it down if you are cutting stuff thicker than .25" and in all cases take a .015" clean up pass.

Check the Onsrud web site, they used to have a lot of info on cutting plastic.

By the way if you have a choice cast acrylic cuts nicer than extruded.

[billystein]

when drilling make sure that you take a fast enough to throw the chip off the drill. if the chips ball up it will melt the top of the part.

[rgollar]

Thank you all for the info. much appreciated.