Chip breakers for plastic

[alsinaj]

Anyone know how to break the chip when lathe cutting plastics that produce long, stringy chips? The "bird's nesting" is a PITA.

[Bruce Griffing]

If you can, score the work before putting it on the lathe. Or cut a groove in it.

[armedandsafe]

If you can, score the work before putting it on the lathe. Or cut a groove in it.

Suggestions for when one is threading, where a longitudinal score or groove would not be desirable?

Pops

[Black_Moons]

vacuum cleaner right behind the cutting tool, suck the swaff up as its made.

[macona]

Pretty much forget it.

Depending on the plastic you can get it to chip with enough of a cut and fast feeds. But you really have to be aggressive to do it.

This is what my lathe looked like after doing a bunch of delrin, this was with about 3/4" off in a pass:


IMGP6526 by macona, on Flickr

[j.bain87]

What a mess, ya should have taken a more aggressive cut, then you'd only have had half that mess.

mark

[beanbag]

Anyone know how to break the chip when lathe cutting plastics that produce long, stringy chips? The "bird's nesting" is a PITA.

You don't. Best you can do is set the right DOC, feed, and chipbreaker to aim the string somewhere convenient.

[garagemark]

Good lord, is there really a lathe under that mess?!

At least it's not too painful to clean up. It won't cut you like a razor blade.

I have never found a way to break the string. I simply try to guide it off to one side of me.

[dockrat]

I seem to have solved the string problem when I switched to a CCGX AL H10 insert designed for cutting Aluminum. It didn't break the string but it no longer piled up ahead of the cutter in a big mess. It shot the string off to the right where it landed in a big pile. One time it was shooting over my right shoulder and landing in a pile on the floor beside me so I put the garbage can there. It just shot right into the can.

[strokersix]

Second the shopvac. Works great.

[bob_s]

If you can cool the plastic to below its ductile to brittle transition temperature it should form chips rather than stringy crap.

[Spin Doctor]

You don't. Best you can do is set the right DOC, feed, and chipbreaker to aim the string somewhere convenient.

I always tried to get the swarf to land right in the circular file

[Peter N]

If you can cool the plastic to below its ductile to brittle transition temperature it should form chips rather than stringy crap.

May be a bit tricky Bob - the Tg (Glass Transition Temperature) temperature of the (probably) 2 most commonly machined Polymers, are -60degC for Acetal and -90degC for UHMWPE.
Nylon by comparison is much easier, as you only have to get that below 50degC.

[bob_s]

Liquid nitrogen

[toolznthings]

Hello,

+ 3 on the shop vac. Works great !