Melting Acrylic/Plastic

[Ger21]

I'd go down to about 12,000 rpm and 2000mm/min. I've used similar numbers on acrylic in the past.

[JAZZCNC]

I'd go down to about 12,000 rpm and 2000mm/min. I've used similar numbers on acrylic in the past.

Last Cast acrylic I cut was 10mm thick and I cut it single pass with 8mm spiral upcut cutter at 24000rpm and 1200mm/min and it left a lovely finish but I thought these figures might scare him. . Lol . . . . Funny stuff acrylic and I find the larger the cutter the better finish I get.!!

[Dwayne Dibbley]

lower spindle speed seemed alot better here are some test results @ 9K 700-800 x 2mm ( im increasing slowly :) )



Thanks for the tips

[JAZZCNC]

lower spindle speed seemed alot better here are some test results @ 9K 700-800 x 2mm ( im increasing slowly :) )



Thanks for the tips

Try increasing the DOC and see if that helps often does. Have the tool under engaged is one the most common reasons for poor finish and excess tool wear.

[m.marino]

Jazz is correct on increasing DOC. Also as Jazz posted you really want to work with Cast not extruded. Cutting a lot of acrylic for sign folks and the best I can suggest has for the most part been stated. The only thing I can add is that you want to stay with either two flute or single flute for the best finish. Also doing a finishing pass in the opposite direction will aid greatly in the quality of finish you get (this does include areas where you have not cut all the way through). The only exception to the second pass I have found is when cutting with a V carve bit, than it is one pass and the job is done. -Michael

[Dwayne Dibbley]

Can you easily tell if the acrylic is cast or extruded by looking at it? ( no it does not have a label on it :) )

Thanks

[cropwell]

With a bit of Internet searching……
.
How to tell whether its extruded or cast:
"Burn a piece , extruded burns silently and will drip molten balls , cast burns with a crackly/smokey flame and wont drip. "
.
"Another point worth mentioning is that extruded stinks when it's cut but cast has an almost sweet smell."
.
And on this forum, from John S in Feb 2013
.
"Extruded has white backing on one side and clear on the other.
Cast has clear backing on one side and white on the other."
.
.
Personally, I would only trust John.

[m.marino]

Can you easily tell if the acrylic is cast or extruded by looking at it? ( no it does not have a label on it :) )

Thanks

Normally Cast has a white film on it and extruded has a clear film on it. Notice I say normally, I have seen otherwise on more than one occasion. That and ask for cast only when you buy it. Be careful though as some will say it is cast over the phone and you will get extruded. -Michael