HDPE bit help 1/8 or 1/2?

[DarinB]

HDPE Help?

I'm working on a project in HDPE. It's .187 thick & I need to cut about 60 full depth pockets in it that measure 1.5 x 1.2. The only bits I have are 1/8" o-flute upcut(Onsrud 65-012) & a 1/2" low helix 2-flute bit for plastics (Vortex 4260). From what I've calculated, if I use the 1/8" bit the machine time is around 7 hours. The 1/2" is around 14 minutes, but at 500IPM. I have an Alpha Buddy, but I've just never cut anything like HDPE, especially that fast. The 1/8" numbers I am using are 60ipm @ 12k rpm & a cut depth of 0.05. The 1/2", I'm using 500IPM @ 9k rpm at 0.1 depth. Any ideas or suggestions?

Thanks
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[knight_toolworks]

you can do that depth in one pass with either bit. 60ipm full depth with the 1/8" is fine it is soft it wants to grab bits a bit so the parts want to move. usually I leave a onion skin on the part it is the only practial way to keep it in palce when you cut through. it is easy to clean up with a knife.

[EricSchimel]

I cut that stuff every week. I always onion skin it so the parts stay put. I use a deburring tool to make a nice clean edge on it when I'm done.

For feeds and speeds to with that 1/2" but. Do 18k RPM, full depth per pass, at 225 IPM and you should see good speed and quality. Using that 1/8" bit is nuts, that'll take forever!

[DarinB]

Will try that... Thanks.. Climb or conventional?

[EricSchimel]

I do climb. The stuff I do is production so it's usually to passes through 1/2" HDPE in the climb direction. If you wanted to clean it up nice if this is a one off, maybe do a pass climb with a bit of an offset, and then come back in reverse (conventional) and take a few thousandths off.

[guitarwes]

Did the inside profile toolpath not work that I recommended on the Facebook group page?

[DarinB]

Sorry for the delay.. Yes those feeds & speeds worked great!! Thanks for the help on it.. After a little cleanup, looks perfect.


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