truing bench grinder wheels

A

ADrummond

Hot Rolled

Joined

Aug 18, 2003

Location

Portland, OR

• Sep 7, 2004

• #1

I've got a bench grinder that's been sitting on the shelf for about two years, and it's time to get it down and start grinding some lathe tool bits with it. My problem is that the wheels wobble axially (they seem relatively true radially); how should they be trued? I replaced the cartridge bearings, and the horrible squeal they made went away, but the wheels still shake. I'm guessing the washers (stamped steel) are just wavy, and that I ought to turn new, flat, maybe heavier ones - is this generally the right approach, or is there something I'm missing? Could they just be junk wheels? I don't recall the brand, but I'll check everything out more thoroughly tomorrow when I get back to the shop. I searched the archive (no sense asking something that's probably been asked before), but surprisingly didn't come up with anything (though Forrest's post from 6/02 on the topic of wheel selection and dressing was very helpful). Thanks in advance,

Andrew

 

G

Gordo

Hot Rolled

Joined

Nov 23, 2002

Location

Oakdale, MN USA

• Sep 7, 2004

• #2

I have had some cheap wheels wobbled and I just tured up the sides with a diamond and the worked fine.

 

johnoder

Diamond

Joined

Jul 16, 2004

Location

Houston, TX USA

• Sep 7, 2004

• #3

Machined washers are a definite plus - be sure to relieve them per usual grinding wheel washer practice.

John

 

M

Michael Az

Stainless

Joined

Dec 16, 2002

Location

Safford, Az., USA

• Sep 7, 2004

• #4

Check the washers carefully. Not long ago I rebuilt a nice grinder and had the same problem when I mounted the wheels. I discovered the bore through the washers had very sharp edges and the turned shoulder on the shaft had a rather large radius so there was no way the washer could run true. I put a radius on the washers bore so it could seat flat against the shoulder of the shaft and problem solved. But maybe your washers just aren't true. A diamond is my favorite way to true a wheel.
Michael

 

A

ADrummond

Hot Rolled

Joined

Aug 18, 2003

Location

Portland, OR

• Sep 7, 2004

• #5

John, thanks for the reminder - do you know why grinding wheel washers are relieved? Is it to prevent damage to the wheel from pressure being applied right around the bore?

 

johnoder

Diamond

Joined

Jul 16, 2004

Location

Houston, TX USA

• Sep 7, 2004

• #6

ADrummond:

My take on the relief in the washer is that it is a stability issue. The relief insures that the maximum OD of the washer is working for you.

John

 

L

L Webb

Titanium

Joined

Jul 28, 2001

Location

Fullerton, CA USA

• Sep 7, 2004

• #7

The problem with a plain flat washer used on grinding wheels is that they deform and put pressure at the hole in the wheel.
That is a great way to have the wheel fail and come apart.

The use of the paper blotters is also a must.

There is plenty if safety information on Norton's website.

http://www.nortonabrasives.com/industrial/safety/tips.asp

Les

 

W

WJHartson

Cast Iron

Joined

Feb 13, 2003

Location

Pass Christian, MS, USA

• Sep 7, 2004

• #8

The relief in the washer is to get the load from the washer away from the center hole. Make sure that you use a blotter, thick paper washer, between the edge of the wheel and the washer on both sides. Make sure that the bore in the wheel is correct for the arbor.

Hope this helps.

Joe

 

D

dvice

Hot Rolled

Joined

Mar 12, 2004

Location

dutchess ny

• Sep 7, 2004

• #9

I concure that the washer is relieved to transfer the force to the outer dia of the washer...thus you need a hardened washer to keep from crushing the relieved part down to the wheel....now I guess you really dont need a lot of torque on the nuts , and really shouldnt be crushing a good thick washer....but you never know.... I have mounted many many wheels, and I dont think I ever remember a whelle that was not parralel.....if its wobbling, my money is on the way it was mounted...either in the washers, or the shaft or a combination of all of them.......of course it could be a tiawanese wheel and maybe I have never seen one of them.......in any case, you do you need to true up the side of the wheel on a bench grinder?......how smooth do you need it?........you could true it on a lathe , then mount it on the grinder.......good luck...bob

 

johnoder

Diamond

Joined

Jul 16, 2004

Location

Houston, TX USA

• Sep 7, 2004

• #10

Speaking of truing grinding wheels in a lathe - at Pratt & Whitney Aircraft during the apprenticeship there was one old guy that did nothing but. Just ran them fairly slow and carved them to shape. I think any old piece of iron will act like a cutting tool this way, of course it too wears away. When they mounted them on the grinders, they finish trued them in the usual way. I always wondered how the lathe made out.

John

 

matt_isserstedt

Diamond

Joined

Dec 15, 2003

Location

suburbs of Ann Arbor, MI, USA

• Sep 8, 2004

• #11

I wonder if cheapo wheels or deformed washers have crushed non-uniformly under the washer pressure?

Seems like I had this same problem with an elcheapo Delta bench grinder.

After loosening the nut and rotating the wheel relative to the washer, then retightening the problem went away. The idea was to get the high spot on the washer over the deepest gouge in the wheel.

Not that this is safe or ideal I think I chucked the grinder shortly thereafter.

-Matt

 

A

ADrummond

Hot Rolled

Joined

Aug 18, 2003

Location

Portland, OR

• Sep 8, 2004

• #12

As it turns out, it was the washers - they're nowhere near parallel. It's an older made-in-Taiwan grinder, inexpensive, but not garbage either. I expect the wobbly wheels are why I got it cheap. It looks as though there's enough material to skim a bit off the side of the washer with the small hole, but I'm probably better off making new, thicker ones. Thanks for your suggestions and observations.

Andrew