3D Machining UHMW With a Tormach

[@tjkirkpatrick9451]

Great clip was the ball nose a particular rake style or regular style for steel ? Cheers Tj

[@williamclark77]

Plain old four flute ball endmill for steel. It was new and sharp. Ones that have been used before on steel don’t cut the plastic great.

[@tjkirkpatrick9451]

@@williamclark77 perfect thankyou for your prompt reply I have a job I need to get out the door today this is a huge help cheers Tj

[@williamclark77]

@@tjkirkpatrick9451 Any time. I do a lot of different materials. I just can't post a lot of it.

[@alabaska182]

What sort of 3/8" end mill is that? Such as flute count, straight or up/down spiral? Part looks fantastic, nice finish! I'm getting quite a bit of chattering even with a finish pass, so my chip load is probably incorrect.

[@williamclark77]

Just a regular 4 flute for steel. It was new and sharp. They MUST be sharp. They won't cut cleanly on this UHMW or ABS without a really sharp edge. This was one from Tormach I ordered. I just pulled the cut file. That was at 5100rpm, .14" radial,. 5" axial, and 50ipm for about .005" feed per tooth. It was finished with a 1/2" four flute ball endmill at 5100rpm, 90ipm, and .02" step over. I use mist coolant. I was getting melting/sticking dry. Must be a pretty rigid setup or it'll flex the material. That was my biggest issue finishing. These are armrests for a power wheelchair. I made several. The final finish was very smooth to the touch once I figured it out.

[@williamclark77]

Oh, the endmills were all regular 30 degree. Some of the 3/8" endmil roughingl was at 75ipm for .0073ipt. I can't remember what it was in the video.

[@alabaska182]

@@williamclark77 Awesome thank you for this information! I will try some of these feeds/speeds out! I have a 1/4" plastic cutting o-flute for UHMW profile cutting, but it's coated so maybe my polished/non-coated aluminum cutting end mill will work better.

[@williamclark77]

@@alabaska182 Good luck with it. Once I finally quit being scared to send it I got much better results and less overheating the material. I never tried any fancy specialty endmills. None of the oddball material projects I get are high enough in quantity to justify it. One of the worst I had was some ROUND parts from 101 copper with weird features and a deep 7/16-20 tapped hole in a thin wall.

[@multiHappyHacker]

Pretty cool idea.

[@ScotY808]

Cool! What is it?

[@williamclark77]

Some special armrests. I made several. Neat project.

[@RoboDriller]

Where did you source the material?

[@williamclark77]

McMaster Carr

[@RoboDriller]

@@williamclark77, they truly do have everything.. Garages, shops, garage doors, probably sell tombstones even.. I didn't think to look for uhmw at McMaster. Thank you for the reply!

[@williamclark77]

@@RoboDriller They do. Their pricing structure can be odd. They're competitively priced on a lot of things. Some stuff makes me think they have the decimal in the wrong spot. Can't beat their service though.

[@RoboDriller]

@@williamclark77, wow, that's an expensive peice of plastic!

[@williamclark77]

@@RoboDriller Yep. Had several of those to do too. Aluminum might've been cheaper. I didn't see UHMW that size anywhere else either.