Chip breaker not working, why not?

[HMF]

I take a cut on my lathe, and am left with a bird's nest of swarf.

Obviously, the chip breaker on my tool or insert is not working properly.

What are some causes and possible solutions of this?

Thanks,


Nelson

 

[Tony Wells]

There are approximately 1.7 million causes. The most popular are: Feed to fast, feed too slow, spindle speed too low, material too soft, tool height incorrect, lead angle too positive, chip breaker geometry incorrect for material type.

Much depends on the material type. Tools generally need to be exactly on center and neutral lead. After verifying these parameters, slowly increase feedrate. If the chips come off too hot from too high a spindle speed, they are soft enough to deform through the chip breaker part of the edge without breaking. Slow it down a little and continue increasing feed. If the chips are too thick, they will not break. Slow the feed rate and start increasing in small steps.

Some insert manufactures can supply approximate values for speed and feed. They are only starting points, however. It takes a little experimentation.

 

[Conrad Hoffman]

OK, I admit it- I haven't ground a chip breaker on a tool in decades. There's no doubt they work and are valuable in a production situation, but for the home shop it seems like a losing proposition. There are always better things to be doing than figuring out why my chip breaker isn't working. If I'm hogging material I just pause briefly every now and then so the chip ball doesn't get out of control. Hopefully it falls down to the chip pan. Then I'll do the finish cut and usually not worry too much since there isn't that great a volume of chips. Yesterday I was making some parts out of mica filled Teflon. Didn't matter much what I did, the spindle and part ended up hidden underneath a big ball of Teflon string.