Machining plastic

Can you attatch the shop vac near the cutting tool?

we machine pu and as Half says have an industrial vac set up running through a 205 litre drum to draw off the swarf.

I'll bet you could break a chip by incorporating this idea.

BottleBob wrote in news:gcKdnaOcEfc369XVnZ2dnUVZ snipped-for-privacy@earthlink.com:

For me, a *slow* RPM and *heavy* feed works sometimes as the chip is thick enough that it breaks. Depends on material though.

In my own hack-machining operation, I sometimes stand at the lathe in autofeed, with a pair of long-nose pliers or channellocks ripping the ribbons off the work/tool as the cut proceeds. It is indeed a pita.

A reciprocating solenoid or air cylinder suitably mounted, with knife-edged hook of some sort, could proly be rigged to go back/forth over the work to pull/tear/cut these ribbons off the work.

I don't know exactly how this would be done, but I suspect a few electric air valves could be hooked up with a limiting microswitch or two to make this happen pretty straighforwardly. Ditto a solenoid.

Perhaps a spray coolant would help to keep the cut cooler, the chips more brittle, ergo more breakable.

Good strong shop vac attached to the cutting tool

Gunner

Thanks everyone, the next time I will try a strong vac. I'm hopeful, but I "almost" see the continous chip as having a evil mind of it's own when it comes to causing greif. I've even seen plastic continuous chips wrap around the lead screw until it was completly covered. Dixon

I can't share my best suggestion, but here's another...

Milling cutters have multiple cuting edges and make chips in pieces instead of long strands. (are the gears turning yet?)

Also consider different tool shapes. You could rough plunge the grooove first. You still get stringy chips, but it changes the nature of them.

We used the vacuum cleaner trick on a recent production job, and it worked great!

We machine LOTS of plastics and urethanes. Whenever I see someone say you can't machine this or that, I snicker.

forget all the suggestions about chip breakers and freezers, we turned a load of this stuff a few years back and the Hoover was the very best. Start the cut and guide the first tail of swarf down the nozzle and the rest will follow.

How elegant! I didn't initially envision exactly how a vacuum cleaner would help, but this is Da Bomb!! Also keeps the place clean!

I would imagine, tho, that at high enough rpm this might be a little touch and go, but still a great solution. Would be good for *any* ribbon-like chip, I would imagine, assuming suff. diam hose/nozzle.

One thing, when you go to pull the chips out of the steel vacuum drum wear rubber gloves. The damn static charge HURTS!

Gary H. Lucas

Drill a hole every 180 degrees or so in the center of where the grooves are going to go (perpendicular to centerline obviously). That will give you an interrupted cut breaking most of the rough chip. Use the biggest drill you can afford a margin of error in Z. Make a depth jig to not exceed the minor diameter. You will still have to deal with stringy finish chips though.