Low RPM Diamond Grinder

Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.

Moderators: GlennW, Harold_V

Post Reply
User avatar
tornitore45
Posts: 2077
Joined: Tue Apr 18, 2006 12:24 am
Location: USA Texas, Austin

Low RPM Diamond Grinder

Post by tornitore45 »

I built myself a slow speed diamond grinding attachment for my lathe, to sharpen brazed carbide bits. Wheel is 6" dia.
The lathe in on a VFD so setting the optimum RPM is no problem other than knowing what it should be.
Is not flooded but get repeated squirts.

It seems to work fine but is hard to assess since I have never experienced better solutions
Slow progress and seems to require higher pressure than expected compared to steel on Al Oxide

My main concern is how to deal with diamond grinding the steel shank. I do snag as much as possible but inevitably some steel gets ground.
I know that at high temperature the steel "suck" the carbon out of the diamond hence the slow speed option. Heat seems to be no problem, cool to the touch.
What is the tribal wisdom on steel touching diamond?
IMG_0434_rotated.jpg
IMG_0433.JPG
Last edited by rmac on Fri Nov 18, 2022 10:13 am, edited 1 time in total.
Reason: Photo Orientation
Mauro Gaetano
in Austin TX
User avatar
tornitore45
Posts: 2077
Joined: Tue Apr 18, 2006 12:24 am
Location: USA Texas, Austin

Re: Low RPM Diamond Grinder

Post by tornitore45 »

Thanks to the nice guy that turned the picture right and removed the note.
Mauro Gaetano
in Austin TX
User avatar
Bill Shields
Posts: 10459
Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
Contact:

Re: Low RPM Diamond Grinder

Post by Bill Shields »

a very elegant solution

how do you grind a tool when you need to -> and you have work in the lathe?
Too many things going on to bother listing them.
User avatar
tornitore45
Posts: 2077
Joined: Tue Apr 18, 2006 12:24 am
Location: USA Texas, Austin

Re: Low RPM Diamond Grinder

Post by tornitore45 »

Sharpening is a batch processing job. The apparatus gets mounted probably once a year to sharpen all that need.
Brazed carbide are standard shapes of which I have several copies so I can set the dull aside and use a similar one.

To grind an HSS tool I have a regular bench grinder. HSS is where the special shapes you realize you need when you have work in the chuck.
Mauro Gaetano
in Austin TX
User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Low RPM Diamond Grinder

Post by Harold_V »

Assuming that the area in contact with diamond doesn't get up to red heat, I suspect that grinding on steel shouldn't create any issues. What is important is that you provide enough fluid to flush the resulting swarf free from the wheel. A loaded diamond wheel resists cutting and requires much greater force to cut. That may be why you're experiencing grinding only under extreme pressure.

Note that slow surface grinding speed is also a limiting factor. Diamond wheels perform very best when operated at elevated speed, for obvious reasons. That, of course, then changes the dynamic of steel in contact with the wheel.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
User avatar
tornitore45
Posts: 2077
Joined: Tue Apr 18, 2006 12:24 am
Location: USA Texas, Austin

Re: Low RPM Diamond Grinder

Post by tornitore45 »

Noticed the cuts goes faster when there is a "wave" of fluid rolling on the top edge. Nedd to squirt more often during cut and wash spinning weel when not cutting.
All in all I got about 50 tools sharpened, that will last years of work at my machining rate.
Mauro Gaetano
in Austin TX
Conrad_R_Hoffman
Posts: 440
Joined: Wed May 24, 2006 8:40 am
Location: Canandaigua, NY
Contact:

Re: Low RPM Diamond Grinder

Post by Conrad_R_Hoffman »

Nothing beats an Accufinish slow speed diamond grinder and I suspect you're setup is very close to that, maybe except the wheels. I've sharpened HSS tools on the Accufinish for 20 years and there's no problem with the wheels. I do add some clearance to brazed tools so the soft steel doesn't get ground too much on the Accufinish, but that's just for speed, not for any concern about grinding the steel with diamond. (Sadly, Glendo doesn't seem to make the Accufinish anymore, or I might have bought one for home.)
Conrad

1947 Logan 211 Lathe, Grizzly G1006 mill/drill, Clausing DP,
Boyar-Schultz 612H surface grinder, Sunnen hone, import
bandsaw, lots of measurement stuff, cutters, clutter & stuff.


"May the root sum of the squares of the Forces be with you."
User avatar
tornitore45
Posts: 2077
Joined: Tue Apr 18, 2006 12:24 am
Location: USA Texas, Austin

Re: Low RPM Diamond Grinder

Post by tornitore45 »

Nothing beats an Accufinish slow speed diamond grinder and I suspect you're setup is very close to that,
Good to know
Mauro Gaetano
in Austin TX
Post Reply