Custom

[secretweaponevan]

Of you lathe users that grind your own bits, do you do so by hand on a bench grinder, or mount a grinding wheel in the chuck like this guy?
METALWORKING HINTS AND TIPS

Seems to take some of the art out of it, but if it is a much better idea, I just might do it.

Thanks.

[Motorhead]

By hand using a bench grinder & tool rest.
320 grit standard wheel for High speed steels, Silicon carbide wheel for the carbide & high cobalt content cutters. Diamond hone for radius dressing.

[Railgun]

Using grinding wheels anywhere near your lathe is NOT a good idea. The wheels abrade as part of their use and the grit flies everywhere. This extremely abrasive grit will wear your bedways prematurely in short order unless you take great pains to sheild your machine with plastic or some other way of avoiding any chance at all of any grit getting onto the bedways.

There's also toolpost grinders used for grinding operations in the lathe. Again, on the rare occastions that no other method is practical I'll move heaven and earth to shield my lathe bed and then vacuum the dust away before removing the shields.

Now on the other hand grinding HSS or carbide lathe tools is a common and frequent occurance. I'm sure as blazes not going to pause my operations long enough to anally compulsively sheild my entire oily lathe bed just to simply grind a tool.

I've got 4 grinders in my shop. One of them has a soft friable medium grit white Aluminium oxide wheel for grinding HSS and woodworking tools along with a gree silicon carbide wheel on the other side for carbide tools. Keep the grinding area at least 10 feet from the machine tools or provide for a barrier if they must be closer. A GOOD barrier. That grit flies like the wind. Especially when you need to dress the wheels to restore the aggresive cutting action to them. A wheel that looks blackish or, heaven forbid, has visible metal embedded in the face badly needs to be dressed.

[Deus Machina]

I squeeze a bit blank in some vice grips and grind with that. I've gashed my fingers a few times when I loosen my grip and it kicks out.

I do have a set of bits with inserts, but for anything not that standard, I make my own. My internal threading bit works well enough, for instance, but it took forever to make.

[kidneythief]

A VERY knowledgable member of the Home machinist group put together a nice complilation covering the grinding of lathetools a while back. Take a peek at the links. If your a machininst and not a member of this forum...you are doing yourself a large in-justice.

The Home Machinist! :: View topic - A grinder for HSS toolbits

The Home Machinist! :: View topic - HSS Right Hand turning tool with chip breaker

The Home Machinist! :: View topic - Grinding chip breakers on HSS toolbits

-Jake

[Phantom Power]

I'm with Railgun on this one, keep the abrasives away from the ways of your lathe as much as possible. I have my bench grinder set up a few metres away from the lathe, facing in the same direction so any grit thrown from the wheels ends up on the other side of the shop.

[Emerald Wolf]

Originally Posted by Railgun

A wheel that looks blackish or, heaven forbid, has visible metal embedded in the face badly needs to be dressed.

You'd just crapped if you could have seen the grinding wheel in our shop at work after one of the other guys got done grinding plastic switch covers with it. (it has the stock 150 grit or so wheels)




I don't know what it is about that place up there. I worked there with a different crew a couple of years ago and the same thing happened (different plastic, it's was nylon bushings that time) on an old crappy "grinding station" they had.

Catchya on the Flip Side.....

Emerald Wolf -- man...

[secretweaponevan]

Originally Posted by Phantom Power

I'm with Railgun on this one, keep the abrasives away from the ways of your lathe as much as possible. I have my bench grinder set up a few metres away from the lathe, facing in the same direction so any grit thrown from the wheels ends up on the other side of the shop.

Thanks for the advice. I must remember to wear gloves when grinding bits (though, not turning). Was at it for about 2 minutes when I gashed the crease of my trigger finger.

[kidneythief]

DO NOT WEAR GLOVES near any moving peice of machinery. Instead of that little cut you may have lost fingers or had your entire hand broken or worse. There was a similiar incident on another machining forum I frequent...where his leather work glove got caught up in a band saw...which cut a Z shape directly across his right hand. A grinder may wreek serious havok on a tangled hand.

-Jake

[secretweaponevan]

Originally Posted by kidneythief

DO NOT WEAR GLOVES near any moving peice of machinery. Instead of that little cut you may have lost fingers or had your entire hand broken or worse. There was a similiar incident on another machining forum I frequent...where his leather work glove got caught up in a band saw...which cut a Z shape directly across his right hand. A grinder may wreek serious havok on a tangled hand.

-Jake

Thanks for the advise.

I was trying to visegrip my bit while grinding and it kept twisting in the visegrips. I tried to move it back, I slipped and got cut.

I was trying to grind VarmintAl's workhorse bit as pictured:

Any suggestions as to how to do this? 15 seconds at a time by hand is going to take hours, and it is twisting in the visegrips.