add-on chipbreakers

A

alinwa

oft dis'd member
I cut my thumb the other day, got hooked by a spiral off the lathe bit. DUMB, but the result of having a weirdly ground bit where I couldn't easily make a chip breaker.

Here's my question; HSS bits..... anyone played with chipbreakers NOT ground into the bit?

I've been clamping other bits like a tiny cutoff blade on edge on top of the cutter, running spring steel wire down to redirect or break the spirals, etc.

Anyone got a tried and true ADD ON chipbreaker for HSS cutting?

al
 
Have you tried grinding a small groove behind the cutting edge of your tool bit with a Dremel and cutoff wheel? That's about the best idea I can come up with. Billy Stevens went to pull a "wire" off a piece of work just about the time the work grabbed the wire and cut his finger to the bone. He doesn't do that anymore.

I realize you specified a chip breaker that was not ground into the HSS but to try to clamp another piece onto the bit seems to be a cumbersome way of doing it when you use small bits like I do.

I ordered some tooling from Arthur K. Warner Co. that uses HSS inserts that give a good finish. You get a little chip weld if you don't use lubricant but if the speed/feed is right you get broken chips. Have you heard of them?
 
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Al, interesting question........I've lost count of how many times I've cut myself with stainless steel string swarf.......I will be intersted in the answers to this.........Ian.
 
THIS IS NOT A SUGGESTION, NOR A RECOMMENDATION

You should never use your fingers to touch chips or swarf in a machine, even out of it for that matter.

In most all machine shops there will be a pair of long needle nosed pliers laying close to their lathes.

DO NOT ATTEMPT TO USE TOOLS WITHOUT PROFESSIONAL SUPERVISION
 
TRA said:
THIS IS NOT A SUGGESTION, NOR A RECOMMENDATION

You should never use your fingers to touch chips or swarf in a machine, even out of it for that matter.

In most all machine shops there will be a pair of long needle nosed pliers laying close to their lathes.

DO NOT ATTEMPT TO USE TOOLS WITHOUT PROFESSIONAL SUPERVISION
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You won't have to tell Billy Stevens twice. :)
 
Of course, nobody would question Al's ability or expertise but I have found anytime I get stringy swarf on a cut I can either slow the speed or feed down or take a little heavier cut and the problem is usually solved.
 
MColeman said:
You won't have to tell Billy Stevens twice. :)
Click to expand...

Yeahhh, I've been very careful up until now....... very very careful. A neighbor of mine had a run-in with swarf while turning a SS aileron driver shaft and just tore his shirt off, cinched it around the wad and walked to his own front door and leaned on the bell until he passed out. He lived, his hand even works OK when it's warm. Mine was much less dramatic but I remember him telling how the worst part was the doctors working to get the tiny blades free from his flesh without further damage. I finally got to find out for myself.

Yep.

It sucks.

al
 
Alinwa, Depending upon which type of tool holder you are using, it is possible to use either an HSS tool blank slid above your tool, or you can mill a piece of soft steel to have a "head" and thin body to clamp into your tool holder above your cutting tool. You can shape the top piece to any angle you want and it will make a fine chip breaker.
 
I won't touch any swarf if the chuck is turning... I handle some delicately when the lathe is off...

I saw a fellow once with both arms in a cast with pins in his fingers and a neck/chest brace connecting it all... he had been pulled into a drill press by chip and around with the bit before the power was turned off... what a mess and he was lucky to live.
 
Dennis Sorensen said:
I won't touch any swarf if the chuck is turning... I handle some delicately when the lathe is off...

I saw a fellow once with both arms in a cast with pins in his fingers and a neck/chest brace connecting it all... he had been pulled into a drill press by chip and around with the bit before the power was turned off... what a mess and he was lucky to live.
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I'm with you 110%....... this badboy hooked me with everything SHUT DOWN! I was coming back past it, I reached in to blow out the bolthead recess and just didn't see the stupid thing. It had that fine 'sting' just as I'd BARELY felt it tug and I knew I was friggin' had.

The only ones more bummed than me were my kids, three of them got an impromptu sermon right there, (I went and got them, they don't hang around while I'm working!) "SEE why I make you stay back???" "THIS is how wicked these things are, THIS is why you have to set 'wayy back on the stool....... if this piece had been moving I'd have filetted the whole side of my thumb off with barely a tug!"


I blame it on my water-cooled tool grinder, SHARP HSS bits make SHARP swarf, and really hard to break.

Mickey, thank you for the cutoff wheel idea!! I'm a dab hand with a powered handpiece ;) I WILL be trying that, WITH safety glasses.

al
 
As you can amagine, this is an ongoing problem in a shop such as ours where we cut thousands of pounds of shavings, a month.

Most tools that have built in chipbreaker capability are very dependent on RPM and feed, or the surface feet per minute. The depth of the cut can also come into play. Some insert have nothing but a little bump on the tool, that re-directs the shaving.

One of the problems with HSS is you often overcome the tools capabilities by the time you reach the optimum senario, in other words, it will not take the heat.

We have just about quit using HSS for anything. That old wives tail of not being able to get Carbide sharp is just that. There is nothing that I can do with with HSS that I cannot do with some type of insert. The main culprit is many of the small lathes used by the Hobbyist lacks the rigidity and power that allows inserts to work.

A good coolant system is the best defense against this stringy shavings, it seems the more heat, the more they will tend to string instead of curl.

The problem with a add on chip breaker is it gets destroyed pretty quick, as it is not as hard as the tool. The best bet is to grind it into the tool.

As for the safety, always remember. Anything that will cut steel will not even be slowed down by flesh and bone. Alas, something I have not remembered at all times, as my fingers, or lack there of, will attest too..........jackie
 
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