Need Help!- Machining Teflon

[yaji63]

Can anyone help me with suggestions to CNC machine (Milling) Components out of Teflon material ? I have used sharp tools but the material melts into the tool and welds itself inside the flutes. Does anyone know of the cutting speeds to be used and the feed per tooth and depth of cut ratios for machining Teflon material ?

Thanks a ton !

[Geof]

Try using two flute high helix cutters with a chip load of maybe 0.005" (0.15mm) per tooth and 5000 rpm for a 3/8" (10mm) diameter cutter, depth of cut about 1/2 to 3/4 the cutter diameter. Maybe reduce the rpm if you still get melting.

The idea with plastics is to have a fast feed so that most of the heat generated is carried away quickly in the chip. Four flute cutters do not have enough space for the chip to clear out and you welding packing and melting.


EDIT: Yes I forgot to mention an air blast, very good idea.

[pgtech@xplornet]

Use a high feed rate & blow air to clear your chips problem is from recutting your chips that melt & tick to your cutter. WD40 sometimes helps usually no problem in teflon but nylon is worse

[yaji63]

Originally Posted by pgtech@xplornet Use a high feed rate & blow air to clear your chips problem is from recutting your chips that melt & tick to your cutter. WD40 sometimes helps usually no problem in teflon but nylon is worse

How am i supposed to apply WD40 during cutting ?

[yaji63]

Originally Posted by Geof Try using two flute high helix cutters with a chip load of maybe 0.005" (0.15mm) per tooth and 5000 rpm for a 3/8" (10mm) diameter cutter, depth of cut about 1/2 to 3/4 the cutter diameter. Maybe reduce the rpm if you still get melting. The idea with plastics is to have a fast feed so that most of the heat generated is carried away quickly in the chip. Four flute cutters do not have enough space for the chip to clear out and you welding packing and melting. EDIT: Yes I forgot to mention an air blast, very good idea.

Would aliminium grade ultra sharp 3 flute cutters work ? I have these with me right now and i would prefer to use these if it does work

I have a 14,000 RPM machine. Will higher RPM hurt and melt the material while cutting ?

[Geof]

Originally Posted by yaji63 Would aliminium grade ultra sharp 3 flute cutters work ? I have these with me right now and i would prefer to use these if it does work I have a 14,000 RPM machine. Will higher RPM hurt and melt the material while cutting ?

Those cutters should work just fine if they have not been used on metal.

Take some cuts with a nice healthy feed and you should be okay.

Don't go too deep, maybe 1/5 cutter diameter and 1/2 cutter diameter for step over to give plenty of room for the chips to eject.

[pgtech@xplornet]

Yes spray just a little as you go it will keep from welding to the cutter

[mc-motorsports]

2 flute HSS only in my opinion. I used to make quite a few parts out of teflon years ago. Another bit of advice, if you ever need to tap a hole, only use HSS taps and run them through a piece of steel first! Tap out 2 or 3 holes minimum in carbon steel before running that tap into teflon, the material(teflon) is too soft and brand new sharp taps will just rip the material out... Teflon is expensive, especially when it's 3" thick plate and mistakes are costly.