Grind Wheels

[steam oil]

Hi
I have recently been given an old Wolf bench grinder by a neighbour who said he bought it in the sixties and has not used it very often. I don’t know what the life of grind wheels are but I don’t trust 40/50 year old wheels kept in a damp garage. As I use both HSS and carbide tipped lathe tools I am not sure what sort of wheel to buy. Could someone please give me some advice.

Brian

 

[steamer]

Well, I would agree that you shouldn't trust the wheels that are on her. A 60 grit general purpose wheel should do....though I am at a loss for what grade.....maybe a "J" wheel? Make sure the wheel is rated for the rpm of the motor!

Always use the paper blotters between the flanges and the wheel....this is very important!

and...

ALWAYS ring test a wheel before you mount it and ALWAYS stay out of the plane of the wheel for at least 1 minute after the wheel gets up to speed.

Some pictures would help me make sure you have all the safety components in place.

Dave

 

[Tin Falcon]

I worked in a grinding shop for a while. the machines were IIRC about 60 years old I would guess some of the wheels were that old as well. and the wheels were run with flood coolant all the time. so I would not worry about age or moisture. you should not use a wheel that one side has sat in water this can create a balance issue.
However it would be wise to dismount the wheels inspect ring test etc. if the wheels are cracked have chunks out of them or are otherwise abused discard them. Grinding aluminum or brass can damage a wheel.
It certainly would not hurt to upgrade the wheels with new ones.
Here is some info on grinding wheel selection.
TC 9-524 Chapter 5
http://metalwebnews.com/machine-tools/ch5.pdf

http://www.mcmaster.com/#abrasive-grinding-wheels/=gf3x0f

Alox is pretty much the standard for HSS. a green wheel will be needed for carbide.
diamond is also good for carbide.
Go with a brand name Norton and 3M are the standard here in the US. Saint Gobain owns Norton . I would Imagine it would be the brand of choice in the UK but other UK members can comment on this one.
Tin

 

[MarioM]

I worked in a grinding shop for a while. the machines were IIRC about 60 years old I would guess some of the wheels were that old as well. and the wheels were run with flood coolant all the time. so I would not worry about age or moisture. you should not use a wheel that one side has sat in water this can create a balance issue.
However it would be wise to dismount the wheels inspect ring test etc. if the wheels are cracked have chunks out of them or are otherwise abused discard them. Grinding aluminum or brass can damage a wheel.
It certainly would not hurt to upgrade the wheels with new ones.
Here is some info on grinding wheel selection.
TC 9-524 Chapter 5
http://metalwebnews.com/machine-tools/ch5.pdf

http://www.mcmaster.com/#abrasive-grinding-wheels/=gf3x0f

Alox is pretty much the standard for HSS. a green wheel will be needed for carbide.
diamond is also good for carbide.
Go with a brand name Norton and 3M are the standard here in the US. Saint Gobain owns Norton . I would Imagine it would be the brand of choice in the UK but other UK members can comment on this one.
Tin

Hi Tin, looking for some information I found this old thread. Could you please explain to me what is a ring test on a grinding wheel?? and what you mean with etc.....any more tests??

Thank you,

Mario

 

[jmshep]

Brian
Take a look at the following free download from UK Health & Safety Executive. I think it will tell you all you need to know and illustrate things like the correct use of paper washers (blotters), mounting and how to do a ring test etc.

http://books.hse.gov.uk/hse/public/saleproduct.jsf?catalogueCode=9780717617395

Re the old wheels - do get rid of them! You have no idea of how they have been used and abused and it is not worth the risk.

John

 

[Tin Falcon]

the ring test

When a grinding wheel is received in the shop or removed
from storage, it should be inspected closely for damage or
cracks. Check a small wheel by suspending it on one finger or
with a piece of string. Tap it gently with a light nonmetallic
instrument, such as the handle of a screwdriver (Figure 5-11inspect for visual damage. Check a larger wheel by striking it with a wooden mallet. If
the wheel does not give a clear ring, discard it. All wheels do
not emit the same tone; a low tone does not necessarily mean
a cracked wheel. wheels are often filled with various resins or
greases to modify their cutting action, and resin or grease
deadens the tone. Vitrified and silicate wheels emit a clear
metallic ring. Resin, rubber, and shellac bonded wheels emit a
tone that is less clear. Regardless of the bond, the sound of a
cracked wheel is easy to identify.).

found on pg 5-10 tc9-524

grinding wheels are like bells should ring clearly when suspended but will sound dull if on a solid surface or cracked.
the wheell should also be balanced.

inspect for visual damage.
tin