Coil Chip After CNC machining of 316 Stainless

[boknose4]

PROBLEM: Our current CNC process is leaving a coiled chip onto the OD of finished part. Part material is 316 stainless, part is threaded on one side and blank on opposite side. At the end of the finished part process, 40% of parts require physcial removal of this coiled chip. The first solution is to eliminate the machined coil from the process. Cutting tool should have a chip breaker to eliminate the string coiled chip. Any recommendations on the correct tool bit that does not leave a string coil? Additionally, is there a parts cleaning machine that can both clean these parts and remove the coiled chip automaticall?

Bo

 

[berkshire]

On the parts cleaning machine, the answer is " it depends." Vibratub machines can remove a lot of corner burrs, however if the chip is too big, the machine will round off the coiled chip and leave it looking like a wart on the corner of your part.
B.E.

You are judged not by what you know, but by what you can do.

 

[MikeHalloran]

The chip breaker alone will probably not be sufficient, especially if the produced chips are ductile. Coiled chips suggest that the surface speed is too low, probably by a lot.

Try doubling the spindle rpm, and doubling it again, until you get indications that the surface speed is too high, then back off a bit. Ideal chips are short, frangible/ brittle, severely distorted, and _hot_ when they fly away from the workpiece. For low carbon steel, ideal chips are orange/white when they fly by, even when a lot of coolant is used. Stainless is a little tougher to deal with, but cutting tools and parameters can make a huge difference.

Don't take my word for it. Call your cutting tool supplier and ask him to send a field engineer to observe your operation in person and make recommendations.



Mike Halloran
Pembroke Pines, FL, USA