toolbit grinder fixture

[jimglass]

In the pic is a little toolbit grinding fixture. It is made to grind 3/8 square bits. Precisly grinds thread cutting bits and grinds 10 degree clearance and rake angles for turning bits. Not only are keen cutting edges obtained but coolant can be used. Saves the tool and saves the fingers
Jim

[Mr.Ed]

Yep, Smart solution.

The only "but" in this situation is, unfortunately i dont have a magnetic holder (correct word?) for this.

And secondly, grinding toolbits...Do you have any tips, tricks, websites etc etc on how to work those toolbits, what angles to grind etc etc ?

For the moment i dont use toolbits. I use replaceble hardened metal bits. But i was told to start using toolbits for a far better finish. I still have a lot to learn on that part.

Ed.

[rceebuilder]

This is my simple tool grinder . I can make engraving bits with it.

Rceebuilder

[pminmo]

Neat jigs, whay is the grinding wheel Rceebuilder?

[widgitmaster]

Look for one of these "Universal Vises" on eBay, they let you do compound angles!

Eric

[rceebuilder]

Neat jigs, whay is the grinding wheel Rceebuilder?

It is diamond stone. I think there is diamond dust inside. It gives very fine finish . I grind hard metal bits with it.

[Mcgyver]

this will give hss basic angles

http://www.metalartspress.com/Sharpe...0tool%20bit%22

unless your lathe is heavy duty enough to warrant carbides, you're better off with hss as the more acute cutting angle requires less force, you can easily grind whatever bit you need and its cheaper!

with a diamond wheel, remember two things - 1) don' use with steel, and 2) with carbide the resultant dust is a (serious?) health hazard , there should be extraction.

[rceebuilder]

Mcgyver , thanks for the info . Can you give more information? Is the diamond wheel dust hazardous or carbide dust?

[Mcgyver]

here's the msds

http://www.endmill.com/software/MSDS_C.pdf

on a scale of 1-10 how dangerous or risky this is, i don't know....but the pro's I know and anecdotes i read suggest they don't want to be around it and these machines need to have dust extraction.

with the cobalt binder exposure possibly being fatal - ouch - and the hexavalent chromium being carcionegenic, it was an easy sell for me

seems to be all from the carbide and what else is in the carbide, not the diamond, still don't use it on steel or you won't have it for very long!

[handlewanker]

Aww gee Mac, when the boss wasn't looking we always used a diamond cupwheel for getting into those hard to reach corners with out the stone wearing away. It wasn't too often but it made life a whole lot easier.
As a matter of interest any workshop dust,grit, oil contaminated metal dust is lung cancer inducing if you do it all the time. I worked in quite a few shops over fourty years, and the dust from small bench tool grinders was always hanging about in the air, when the sun shone through the windows. One of the hidden hazards of general shop work. The next time you're in a factory have a look on top of a cupboard and note the layer of dust.
As far as carbides are concerned, I wouldn't dream of turning cast iron with HSS. Too much tool point/edge wear.
I also have a set of brazed on carbide screw cutting tools for finishing a thread when you just want to get that last thou and polish it too. The tool angles are made to suit 60 deg and 55 Deg, left and right hand threads.
As they are only used for finishing the top is ground flat and this enables cleaning up both flanks of the thread.
The set I've still got were made in 1962 when I finished my 'prenticeship, sort of a send off present.
Ian.

[Mcgyver]

you point of it all being bad is taken. I remember seeing a pic once of late 19th/early 20th century knife grinders, they lay prone with their faces inches from 4' dia wheel. they had very short life spans, succumbing to a variety of lung diseases, so you're point of it all being bad is taken. some googling surprisingly shows we've not learned our lessons! http://www.rps.org/images/portfolios...fe_grinder.jpg

you're the voice of experience, I'm the weekend end warrior so mostly I defer to you guys....on the general grinding I agree, but my concerns are specific to carbide, not grinding in general. I've got a fair bit of grinding equipment and other than a paper mask for surface grinding, don't worry that much about it - its infrequent and for short durations. but the carbide grinding is another matter, the parts per million needed to be dangerous for the cobalt binders are very low...enough that its a different risk than grinding steels. I also use carbides for CI and use some diamond hones and a bit of water (nothing airborne that way) to touch them up

[Ken Stuempge]

Here is what I just came up with. A few more attachments coming soon.

http://thehermitsmachineshop.com/Grinding_Fixture.html

Ken