Fitting New Grinding Wheels?

[wizer]

Hi guys

I picked up a new white grinding wheel whilst at S&B last w/e. It was a bit of an impulse buy as they where by the counter! I tried to fit it last night and realised that the bore was slightly too small. It looked like a softer material inside the hole, so I drilled it out with a 15mm forstner. However, I didn't get it central. So when I mounted it on the grinder and started it up I got huge amounts of vibration. I dressed it with the diamond tool, but it's still got quite a bit of vibration. Especially when slowing down.

Is there anything I can do? How should I have done it?

Cheers

 

[Jenx]

Did it have the plastic reducing bush in it Tom ?

Some wheels have a large central hole and are 'bushed down' with a plastic ( nylon looking white type stuff , usually ) reducer.

Was it this that you had drilled out ?

 

[wizer]

No it was a stone like material, bluish in colour. Will take some pics tonight

 

[big soft moose]

sorry to say mate i think you've buggered it - the vibration is due to it being out of centre and theres not a lot you can do about that - its not a good idea to start chopping bits off stones as that can create flaws that could cause them to explode in use with serious consequences for you as the user.

so basically you need a new 'un and its a good move to measure you grinder spindle before ordering - and if it doesnt fit take it back.

 

[wizer]

(homer) #-o

Thanks Pete

 

[CHJ]

All is not lost Tom,

Turn up a wooden bung just a bit smaller in diameter than the inner hole size of the wheel, cut to length a fraction short of the wheel thickness.

Fit scrap wood or MDF Mount to faceplate.

Turn recess in mount to take external diameter of wheel.

Clamp the wheel to faceplate around the edge with wood/MDF washers. Not much more than finger tight.

Check the perihery is running true.

Bore out central hole filler with HSS tool until bung is good fit..

Fit Wooden Bung in wheel, not over tight but no slack. (Hot melt glue perhaps to hold it)

Re-drill central hole to suit your grinder shaft.

 

[wizer]

:?

Cheers Chas I will have a go at the weekend. Nothing ventured...

 

[CHJ]

Just take care not to crush stone when clamping, hold it just tight enough to stop it coming out of recess. (avoiding risk of creating stress cracks in wheel)

 

[paulm]

Would it not be possible to stand the grinder on end temporarily so the shaft is vertical and then centre the wheel on the shaft by eye and fasten with the washer and bolt.

Won't be perfectly true but close enough to then be able to true up with a dressing tool ?

May be unsafe perhaps on a high speed grinder (?) but works for me on an old hand-cranked grinder, but obviously lower speed and therefore forces being applied....

Cheers, Paul

 

[wizer]

sounds interesting Paul. It's a slow speed cruesen so not mega fast.

 

[Cign]

Wizer, sorry to hear of your grinding wheel woes. Coming at this from an engineering aspect, I was always tought that grinding wheels were nasty dangerous things if not treated correctly. I copy below a manufacturers (Grindwell Norton) recommendations:-

MOUNTING THE WHEEL
1. Select correct wheel for your operation. “Ring” wheel and inspect for cracks. Never use a cracked wheel.
2. Never exceed maximum safe speed established for wheel. Be sure machine speed is not excessive.
3. Never alter hole in wheel or force wheel on spindle.
4. Use clean, recessed, matching flanges at least 1/3 wheel diameter.
5. Use one clean, smooth blotter on each side of wheel under each flange.
6. Tighten nut only enough to hold wheel firmly.
7. Adjust wheel guard and put on safety glasses before starting wheel.

Hope this helps, personally I wouldn't take a chance even at 1440 RPM there is enough oomph to make broken bits of wheel painful.

 

[jpt]

The only thing to do with the wheel Tom is throw it in the bin.

As John/cign says grinders might look fairly safe but in reality they are one of the most dangerous tools found in the turners workshop.

I have seen a wheel shatter on a slow speed grinder and the person using it ended up in hospital, nothing major but scary all the same.

john

 

[boysie39]

Wizer, you either have too much time on your hands or at the moment Skint, which ever it is Dump the bloody wheel its an accident wating to happen . And we dont want anything to happen to you ok. REgards Boysie.

 

[wizer]

Skint

Thanks chaps. I will almost certainly chuck it in the bin, but if I can salvage it then I will try.

 

[CHJ]

Thanks chaps. I will almost certainly chuck it in the bin, but if I can salvage it then I will try.

The main safety point Tom is as has been mentioned above, whatever you do to it make sure that it 'Rings' like a sound piece of china before you fit it. Try it now before you clamp it etc. just a gentle tap with a piece of hard wood something small and metallic.

If it sounds dull and lifeless then hit it harder to shatter it and throw it in the bin.

 

[wizer]

no other uses for the wheel? slip stones?

 

[lurker]

Tom,

I try to steer clear of H&S issues on this forum, but

Amongst othe things, I teach Abrasive wheels safety.

If you want to see a heart rendering tale from a craftsman who was instantly blinded (both eyes) when a Wheel exploded (during dressing), I can oblige.

dump it in the bin mate ------------ PLEASE!

 

[lurker]

Thanks chaps. I will almost certainly chuck it in the bin, but if I can salvage it then I will try.

The main safety point Tom is as has been mentioned above, whatever you do to it make sure that it 'Rings' like a sound piece of china before you fit it. Try it now before you clamp it etc. just a gentle tap with a piece of hard wood something small and metallic.

If it sounds dull and lifeless then hit it harder to shatter it and throw it in the bin.

IMHO & (and much experience on the subject) this is something that needs properly demonstrating - it can't be learned from "words".
Done correctly its a 8 point ring test

 

[wizer]

ok ok I submit! :lol:

I will get one at the weekend.

 

[Jonzjob]

Wiz, just looking at your signature says it ALL me-thinks.

File it in the round file under your bench mate because I'm sure that we would rather talk to you than about you?

I just realised that there are 2 pages to this thread

Good for you Wiz, it will be cheaper in the long run.