Poorman's grinding tool for vertical mill

[evil monkey]

Items you will need: 4.5" depressed center grinding disc with 5/8" center hole , 3/4" round stock about 6 " long , 1 1/4" or 1.5" round stock, a 5/16 nc tap ,5/16 socket head couter sunk screw , washer that fits the ID depression of the depressed center grinding disc, a counter sink or center drill for the washer.
I will share this idea assuming people on this site, still typing, have common sense , most of their fingers and at least one eye .
Drill your 1 1/4" or 1.5 stock for 5/8" to a depth of about 1/2". cutoff a spacer about 1/4" thick, face one side. You can cut it thicker , this is not critical, you will face the other side later. Turn your 3/4" 6" stock down to a few thou over 5/8", for a distance up the shaft 1/4" plus the thickness of your grinding disc center depressio. You want a snug fit on the grinding disc center hole so take some time here. Relocate items to welding table. Slide the spacer on the shaft with faced side to shoulder and tig or stick weld in place. About three tacks around the shaft with good penetration. Return to lathe and face the side that will face the disc. A good facing job is necessary. . Check fit for disc and washer and either face a little more off the shaft or the shoulder so the grinding disc sits flush with the end of the shaft. If you faced the outside shoulder carefully and the disc is snug on the shaft you are ready to drill the center and tap for the 5/16"NC screw. Assenble the disc , washer and screw. Counter sink the washer so the screw fits flush. Everything on this side should be below the grinding surface.
Run your verticle mill clockwise so it always tightens the disc screw while grinding "because you won't like the taste of grinding disc running it counter clockwise". I use a moderate to slow speed and limit grinds to about .003 max. Moderate speeds and low feeds will give a mirror finish . I have run coolant during a grind without any problems other than it's messy. This doesn't replace a surfce grinder but it works well on vise jaws and similar width projects .

 

[john.k]

Dont get grinding grit and swarf in the precision slides of your mill.

 

[DDoug]

Items you will need: 4.5" depressed center grinding disc with 5/8" center hole , 3/4" round stock about 6 " long , 1 1/4" or 1.5" round stock, a 5/16 nc tap ,5/16 socket head couter sunk screw , washer that fits the ID depression of the depressed center grinding disc, a counter sink or center drill for the washer.
I will share this idea assuming people on this site, still typing, have common sense , most of their fingers and at least one eye .
Drill your 1 1/4" or 1.5 stock for 5/8" to a depth of about 1/2". cutoff a spacer about 1/4" thick, face one side. You can cut it thicker , this is not critical, you will face the other side later. Turn your 3/4" 6" stock down to a few thou over 5/8", for a distance up the shaft 1/4" plus the thickness of your grinding disc center depressio. You want a snug fit on the grinding disc center hole so take some time here. Relocate items to welding table. Slide the spacer on the shaft with faced side to shoulder and tig or stick weld in place. About three tacks around the shaft with good penetration. Return to lathe and face the side that will face the disc. A good facing job is necessary. . Check fit for disc and washer and either face a little more off the shaft or the shoulder so the grinding disc sits flush with the end of the shaft. If you faced the outside shoulder carefully and the disc is snug on the shaft you are ready to drill the center and tap for the 5/16"NC screw. Assenble the disc , washer and screw. Counter sink the washer so the screw fits flush. Everything on this side should be below the grinding surface.
Run your verticle mill clockwise so it always tightens the disc screw while grinding "because you won't like the taste of grinding disc running it counter clockwise". I use a moderate to slow speed and limit grinds to about .003 max. Moderate speeds and low feeds will give a mirror finish . I have run coolant during a grind without any problems other than it's messy. This doesn't replace a surfce grinder but it works well on vise jaws and similar width projects .

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[michiganbuck]

Grinding machines are designed to keep gravity-directed and work-directed abrasive grits out of precision places. Most early-made common lathes and mills are quickly destroyed by using them as grinders.

Evil Monkey Joined on Feb 5, 2023, and has only 3 posts so he/she may not be qualified to give Master or Journeyman advice.

Likely I could put a flapper on a surface grinder and use it for a shaper..

 

[eKretz]

I'll just say: you do whatever you like on your machine. I'd be real careful with doing that except in a pinch, once in a great while. And I'd be taking whatever precautions are possible to keep grit contained. And preferably using someone else's machine...

 

[reggie_obe]

Perfectly acceptable when done on any machine with the Grizzly label on it.

 

[rons]

I got a suggestion about making a holding fixture for woodworking planer knives and using a mill with an abrasive cup wheel.
Tried it out. After that I went back to a Hitachi wet grinding wheel.

 

[SeeFair]

John Grimsmo does this on (of all things) a Kern. He goes to some lengths to keep grinding dust out of the coolant. I am not qualified to judge whether it's a risk to his machine or not, but I sure wouldn't do it on my old mill.

I think this is the video that describes his provisions for filtering the coolant, although I did not go back through the vid to make sure.

 

[evil monkey]

Not something I do daily and the ways have covers . I also cover the table .

 

[evil monkey]

Dob't get too wound up , it's just an alternative if you need one . Hopefully no one felt obligated to build on the idea .

John Grimsmo does this on (of all things) a Kern. He goes to some lengths to keep grinding dust out of the coolant. I am not qualified to judge whether it's a risk to his machine or not, but I sure wouldn't do it on my old mill.

I think this is the video that describes his provisions for filtering the coolant, although I did not go back through the vid to make sure.

Grinding is a risk even if everything is covered but you can minimize the risk with common sense.

 

[CarbideBob]

Most people say do not grind a B-port style vertical mill.
So lets look at a Harig 6x18 surface grinder.
Hmm.... seems the left/right table ways are oil coated and just as exposed as my B-port left/right ways.
So now we are down to the in/out and up down.
Even if not used for grinding way covers are for sure your friend.
This leaves the quill but have not seen that used very often in grinding applications.

VMC mill grinding and coolant.
Way covers not water tight so some consideration of where they drip inside if doing production.
The coolant coming off has fines in it so filtering the coolant in is not a solution as too late but one does not want an abrasive slurry going back in.
The filtered coolant back in is more for surface finish.

Toolpost grinder on a lathe. I think this is common. You need to rig something to catch most of the bad stuff or over time this bad.

I will go with my standard response on a open machine. Cardboard, duct tape, and shop vac.
I grind on B-ports, VMCs, and Lathes. Some steel but mostly carbide. The problem on all these is size control down in tiny small numbers
I'm sure tungsten carbide grit is not abrasive against steel ways so no worry there.

Interested to here real world work by others where this has torn up the machine tool and made it scrap.
I know of one member here doing carbide grinding on a Hass 3+2 or maybe a five and beat it to death over a long time. I think he bought an Anca and showed it?
A well respected name out of California and by all calls a great shop. Do not see him much around .... maybe the busy little beaver which I do hope for him.
Bob

 

[eKretz]

Lotta work that most don't do... You could put a Ferrari engine in a Yugo too...

But like I said, in a pinch and with as much of that protection as you can muster. Preferably on someone else's machine.

And I'd be mostly concerned with the saddle ways and the knee ways, where stuff is just gonna run down. With the Harig or other surface grinders at least you're most likely going to have flood coolant catching most of the airborne grit. And most of the better grinders have a nice drip edge set up so that the coolant doesn't get to the underside of the ways. I still like Buck's idea with the tape strip though.

 

[Scottl]

Many years ago I used something similar on a drill press, with sheets of typing paper added as the "feed". The work was passed under the cup wheel by hand. Have also done woodworking chisels that way, mounted to an angled wood block.

There is the right way, the wrong way, and what you do sometimes to get it done.