Whippy Chips

[Ed McDonnell]

I've been turning down the heads on some grade 2 steel 5/8-11 bolts and the hexs on matching nuts. The chips on the bolts turn into these long (12" - 24") writhing snakes that are making me a little nervous. I stand back from the lathe, but eventually I have to use the controls. I don't like having to move my hands in towards the controls with these things jumping around. A quick wrap around a finger or wrist and people will be calling me stumpy.

I've not encountered this with other metals (aluminum, brass, 12L14 Steel and T-303 stainless). The nuts don't do this. The chips from the nuts break off when they are about an inch long. Plastics will have long chips, but they usually just wrap around the work and are only a minor nuisance. But the chips off these screws are something else.

Adjusting speed and depth of cut hasn't made much of a difference. I'm using HSS indexable cutters. The lathe is a 7x16.

Any suggestions on how to kill the snakes?

Ed

 

[Haynie]

I've gotten these before. Don't worry they are usually hot enough to cauterize the wound when they lop off a finger.:biggrin:

If they are getting unruly I just stop everything and clip them off. That is the cool thing about a metal lathe. If you stop it, then start it again, it picks up where it left off. Most of the time I just let it go until the cut is done.

Oh yeah. I also will wear a glove sometimes when I clip the swarf off. Those things can be nasty sharp and damned hot.

 

[ironman123]

Ed, when I get those with some steels, I hold a 2 inch wide brush over the tool and most of the time they will deflect and break off at 5-6 inches.

Ray

 

[Ed McDonnell]

Hi Ray - I'll give the brush a try on the next one. Thanks.

Hi Haynie - I had tried stopping and starting the feed. It worked, but my little 7x16 has enough flex when cutting steel that interrupting the cut leaves a faint mark. I guess the marks wouldn't matter on the roughing cuts, but having to constantly stop and start the feed really slows things down. I'm going with Ray's brush idea, but thanks for the suggestion.

Ed

 

[Haynie]

Ray has a good idea then.

 

[Ed McDonnell]

Ray has a good idea then.

I hope so.:biggrin: I won't get a chance to try it until tomorrow.

Ed

 

[SteveG]

You are using indexed cutters, but if you were willing to use standard cutting tools, I think there is a way to grind the tool bit to cause the coils you are producing to instead break up as very short pieces. I am not experienced enough to describe the grind to use. I am just passing along a bit of information that I believe to be true, but have no first hand experience.
Steve

 

[cwolfs69]

You are using indexed cutters, but if you were willing to use standard cutting tools, I think there is a way to grind the tool bit to cause the coils you are producing to instead break up as very short pieces. I am not experienced enough to describe the grind to use. I am just passing along a bit of information that I believe to be true, but have no first hand experience.
Steve

yes you can grind a chip breaker into the tool. if you have the right grinder you could actually grind the chip breaker into the indexable tool. don't try it with carbide however.

 

[Paul in OKC]

Grade 2 bolts ore some pretty gummie metal, hard to break a chip with those anyway.

 

[Ed McDonnell]

Using a brush to break the chips works some of the time but not enough of the time. I tried a metal ruler and that worked a little better to break the chips. My wife came out to the shop and saw me swatting at the metal lathe with the ruler like I was in some kind of sword fight. I can imagine what I looked like. I don't think she had her camera with her.....hope not. :redface:

I went with grade 2 bolts because I thought they would be easier to turn. Would a different grade be less gummy?

I didn't use aluminum because I don't want issues with thread galling. I didn't use brass because of the cost. I'm not cutting my own threads in better steel because I don't have any way to cut internal threads and 5/8-11 taps and dies are pretty pricey. It wouldn't cost much to buy a different grade of steel bolt if that would work better.

Ed

 

[ironman123]

Ed, sorry the 2" chip brush didn't work for you. Hope you get it worked out. Let us know if going to a different grade of bolt solves the problem if that is the way you go.

Ray