Cutting Acrylic

[Gujustud]

I'm starting to do more acrylic work at the shop, and was wondering whats the best way to cut acrylic? Mainly sheets, anywhere from 1/4" to 1".

I'll be doing this on either a Haas VF2, or VF7. Btw, I should be more clear when I say cutting, but milling parts out of the sheets.

Thanks in advance!

btw I wasn't sure where to post this, so please move the appropriate section if needed.

[Rekd]

I moved your thread here from the announcements section.

Cutting acrylic is not too bad. Use sharp cutters, avoid excessive heat, (melted plastic built up in flutes makes for nasty burrs! ), and try to cut into the material to avoid chipping as the end mill breaks out.

HTH

'Rekd

[KingPANO]

Make sure that your acrylic/plexiglas is a cast plastic not extruded. Extruded is noted for the melting and wrapping around your endmills. I cut cast acrylic with a 1/16 bit 30-40ipm rough with 15 ipm smooth pass. I get great results.

Bill

[marvinstov]

I don't know much about acrylic. How do you tell if it is cast or extruded?

Marv

[KingPANO]

Originally posted by marvinstov I don't know much about acrylic. How do you tell if it is cast or extruded? Marv

75%-90% of the time if the paper on the acrylic has writing on it is extruded...ie. the cheaper version of acrylic. I've ruined more bits by using extruded plastic. Cast is the more expensive but worth the .50-.75 extra per square foot. I have a good relationship with my local plastic fabricator and he gave me the tip.

Most of the plastic places will have a scrap bin that they will let you rummage through for a dollar a pound.

Bill

[Gujustud]

Originally posted by KingPANO Make sure that your acrylic/plexiglas is a cast plastic not extruded. Extruded is noted for the melting and wrapping around your endmills. I cut cast acrylic with a 1/16 bit 30-40ipm rough with 15 ipm smooth pass. I get great results. Bill

Good call (on cast vs. ext).

1/16 at 30-40ipm? How deep?

[KingPANO]

I cut about 0.1 each pass. The smooth pass takes off 0.02...with great results.

I've never cut wood or aluminum on my machine...only acrylic and HDPE. I'm entertaining an idea of making a collet out of aluminum for a larger router than my rotozip.

Bill

[Laff Riot]

May want to take a page from new hermes book and use a large laminate router with a 3" wheel on the end - they transfer the rotation using a rubber belt to the small spindle head increasing the rotation at the spindle by 2x the router speed.

I like this system as the bits are the only thing that get sacrificed when you bite into something. If the bit gets lodged the rubber band will break or spin freely without damaging the router.

If you need pics of this lemme know soon - I am getting the NH machine out of my shop in exchange for a laser. Will only have it for another cpl weeks I hope.

Like Rekd said cut into the material - commonly this is done by reversing your curve in your generation program or selecing climb cutting if you have the option. This leaves all the melted chips on the side of the waste substrate not your cutout piece, you will still have some flecks that need to be knifed off but the final edge can be cleared again using an oxygen torch and light passes.

[boxwood]

Hey guys what material for lithopanes, I had read acrylic so bought some on ebay called called plexiglass acrylic (clear) but when I cut the picture doesnt look anything like a lithopane! shoulf it be colored? what color, also read corian is good but isnt that stuff solid color so no light gets through and its thick from what I saw at HD any in put would be greatly appreciated

[DareBee]

I have not milled acrylic but am familiar with polycarbonate, I find it works best with coolant. Considering you are doing this in a VMC maybe you could give it a try and then it won't matter if it is cast or extruded.

[ger21]

Corian is translucent, the thinner you cut it the more light will show through. It would need to be backlit, though.

[miljnor]

I like this system as the bits are the only thing that get sacrificed when you bite into something. If the bit gets lodged the rubber band will break or spin freely without damaging the router.

For this to work right don't you have to have some mechanism to stop the forward Feed of the machine.. I don't think most machine tools care if the cutter is there or not (Ba$tards ). An overload sensor or something?