Removing bench grinder wheel covers

[roombacurious]

I'm thinking to make a custom tool rest for my el-cheapo 6" bench grinder and was wondering whether I could remove the wheel covers - for good.
My understanding is that they are there protect the user from flying pieces of metal and prevent accidental contact with a spinning wheel. However, as I found out (https://www.ukworkshop.co.uk/forums/viewtopic.php?t=23055) although they do stop metal grounds flying they can also be dangerous. If the wheel catches your finger it can wedge it against the cover and grind it to the bone.

Do you think it is dangerous to take them off permanently?

I would think that if your hand comes into contact with the spinning wheel you'll certainly get a burn but in all likelihood the wheel will "kick it off" preventing anything more serious. As for preventing eye injury I always wear a full face mask when grinding. Using a tray with some water under the wheel should catch some of the grounds anyway.

What do you guys think?

 

[Racers]

Hi,

So instead of a small portion of the wheel exposed you want all of it in the open! what if something fell against the spinning wheel? Sounds like madness to me.


Pete

 

[HandyTim]

The covers are there to contain a wheel burst, please leave them on.
Fortunately I've never had one, but I can imagine lumps of abrasive wheel flying off at high speed is not very pleasant!

 

[gidon]

I'm not quite sure why you need to remove the guards - here's my tool rest - you don't get a lot simpler:



Nicked from Lee's sharpening book - except ran out of time - it should be able to slide back and forth against some outside pieces of wood - hence the slot in the middle.
If you make something like that don't use oak like I did . (Doesn't mix well with water and iron filings!) Bizarre thing is this is the second attempt at a tool rest - both made of oak - doh! (In my defence always seem to have convenient pieces of scrap oak for some reason).
Cheers
Gidon

 

[lurker]

Don't do it!!!!

All tool guarding is necessary and quite frankly some equipment available to the public is not adequately guarded, but I've yet to see anything over guarded.

I have some photos of the outcome of a wheel burst (bits embeded in walls) and the photos of the poor bloke having his face rebuilt (but not his eyes which were both destroyed) . they need a strong stomach to view.

I deliver training on abrasive wheels use and use these photos to shut up the class know all who thinks he needs no training.
When they start, I say nothing just switch PPTs and click through the photos. Ask if there are any one else who thinks they don't need advice and then get on with the course.

 

[Woody Alan]

Lurker

I have heard it said that if a wheel is going to go it will do it on initial spin up or wind down. Is this correct. What is the likelihood of a burst and how can it best be avoided.
I try to be safety conscious and use my machines in the proper way but none of them ..as far as I know are likely to self destruct other than through my incompetence.
If there is no absolute safe way to guard against this I will chuck mine out as there are other ways to skin a cat.

Alan

 

[roombacurious]

Convinced... :shock:

I hadn't thought about the exploding wheel scenario...
Put on balance I'd rather have my finger ground again rather than bits of wheel embedded in my face.

Thanks for the advice!!!

 

[Digit]

You are a fortunate man Tim! I was working on a mill one day and between it and the surface grinder was a Hardboard screen to catch any sparks.
The chap on the grinder need to dress the wheel and as he didn't want to wind the wheel down, it had no power feed, he clamped the diamond to an angle plate.
Unfortunately he forgot to turn on the magnetic base. Next moment diamond and lumps of wheel went clean through the hardboard and over my shoulder!
And bugger me but he did the same damn thing again a few minutes later!

Roy.

 

[dennis]

Lurker

One thing that I find odd that you may be able to answer concerning petrol cut off saws is that you need training and a certificate to change a blade,which is as it should be,but you do not need any training to use the saw.That is unless things have changed recently.

Dennis

 

[johnjin]

There is probably no tool in the workshop needing guards more than a grinder. You should check any wheel carefully for cracks before putting it on the grinder. Put a finger through the hole and give it a gentle tap with a spanner or something and listen for a clear ring. Never jab anything into the wheel, always approach it carefully and slowly. If you must use the side of the wheel use only the minimum amount of pressure. Grinders are very safe if used properly but if you abuse them, the results can be catastrophic.

Best wishes

John

 

[lurker]

Woody,

So far as I'm aware wheel burst is usually down to misuse eg using the side, too much pressure etc.
If you get a small item snatch and it jams between the wheel & rest then that will usually have dire consequences - thats why its a good idea to frequently adjust the tool rest so its as close to the wheel as possible. In my experience it makes grinding easier too. I have an Axminster rest at home, Giden's home made one is a good idea too - I was just too idle.
The angles we woodys generally use are far safer than grinding your material at 90 deg to the wheel

The more friable and /or wider wheels are more susceptible to bursts, its best to run these on slow machines. As it happens most bench grinders we use are OK because you only have the safest quarter unguarded. Most likely time is just after remounting a different wheel and people are tempted to run the wheel up "just to check its OK before refitting the guard".

Dennis,

In my industry we have two levels of training use & wheel mounting. In the case of cut off saws its not exactly rocket science. For these tools, I can deliver "use" in about 45 mins including all admin. Use & mounting takes about 60 mins.

If you get onto engineering shops were grinder wheels require balancing etc you are looking at a day course

John,

You are nearly right!
Your finger will deaden the ring and clonking the wheel with a spanner is not a good idea. I teach using two pencils - one through the hole ( being careful not to touch the wheel with your hand) and then hit the side of the wheel with the other pencil ( held at 90 deg to wheel side) then repeat at every quarter, the wheel should "ring". I have a damaged wheel to illustrate the difference and its quite easy to tell.


finally................ I always use a full face mask when grinding.

 

[dennis]

Lurker

Regarding cut off saws I know that it is not rocket science to change a blade.What I was saying is that in these days when you need a ticket for almost everything it seems odd that you do not need one to use a cut off saw which can be dangerous tools especially if used incorrectly,which is often the case.I have seen people sharpening cold chisels on the sides of the blades and grinding sharp edges off bars also on the side of the blade.One safety instructor told us that there was a case of someone mounting two blades to cut brickwork joints out in one go.I was watching a young bricky cutting a heavy steel bar on the ground one day and the blade started breaking up,he didnt even realise and kept trying to cut while I was shouting at him to stop as I didnt want to get near the shattering blade,the saw was bouncing about and when he did stop and I showed him the shattered blade he seemed surprised and said,I thought it wasnt cutting very well.

Dennis

 

[big soft moose]

definitely leave the guards in place - as regards the finger getting cuaught angle their shouldnt be room to pull a finger down inside the guard (mine -cruesen-has about 3mm clearance between wheel and guard) if el cheapo has i 'd suggest making or buying a sharpening platform to eliminate this gap.