Cutting Nylon

[Phil Orenstein]

I will be getting in a job to machine 50 small parts in high temp nylon involving milling & turning. Never having machined this plastic before I submit to the knowlegeable opinions of my friends on the forum. What speeds & feeds, air or coolant etc. Any thoughts on the matter would be appreciated.

 

Phil

[mold100]

I use air and very sharp high speed steel. I run in pretty fast trial and error, I dont cut it daily but monthly.I will look back and see what my last jobs speeds and feeds were if I can find them. More important will the parts be rigid or flimsy, keepin em flat or straight can be an issue. (Oh you said high temp nylon, I dont know the differance )

[Surface]

Ahhh your in for a treat. Nylon is not hard to cut, but it is dimetionally unstable and creates burrs like crazy. Highspeed endmills work fine (they tend to be sharper than carbide). I generally cut dry or with air because the nylon will absorb the oil from your coolant.

[Harryman]

Always cut every feature with a cutting tool. No abrasives.

[Philcott]

Hey Phil,

 

I have not done much milling but have turned lots of nylon. The biggest problems have been with chips wrapping around the part and melting onto the part. Use coolant and try to position the coolant line to blow the chips off the part and tool. Perhaps a M00 to clear chips after roughing might be a good idea. Clamping can also be an issue as the material is soft and will distort with too much pressure. Watch for your part distorting after parting off or unclamping. You can use fast speeds and most any feed you need to create the required finish. Hi-positive cutters can sometimes pull the material put of you chuck or collet.

 

Good luck,

 

Phil

 

PS. oil absorbtion has not been concern for us.

[Phil Orenstein]

Thanks, my friends. Sounds like I'll be having a fun week except for the burrs or strings, maybe similar material cutting parameters to the polypro job I recently did.

 

Phil

[Oppiz]

I've cut nylon many times. Crank it up. A couple of thing to watch for are:

If holding it in a vise don't over tighten.

 

Tapping can be a pain. Chips get wrapped around the tap. I found that a standard gun tap works better than a spiral.

[George_Gerhard]

Phil

I have cut nylon many times on routers, do you have high rpm capability?

If yes then go 16-18,000 rpm Onsrud has a cutter 60-249 which does a nice job

 

rgds

George

[Chris Rizzo]

+1000 on the material instablitly when milling "billets". On thinner stuff I end up flipping it a few times when facing, so that equal material is removed from both sides...balancing distortion...

[Phil Orenstein]

That clarifys another problem with bending and warping when I was cutting thin Polypro parts. Fortunately the warping wasn't an issue and there wasnt enough $$ in the job to filp it a few times.

 

George, my spindle barely cranks out a measly 6000! It would be nice to have decent equipment!

 

Phil

[Tom Flyer]

Leave a fairly heavy cut for finishing, .025 or so on a side. You'll be most of the day trying to get .003 off the stuff, the rest of the day will be spend unwinding the string-chip off the chuck, workpiece, tool holder, etc.

Yuk.