Bench grinder

Has this happened to you?

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My 6" Clarkes bench grinder has sat in the corner doing its job without complaint for years, but the wheel had got grooved and the wheel was rather too coarse for a fine edge on HSS

So i thought Ill put a new fine wheel on and bought a named brand not cheap PRC - another story there

So imagine my surprise when it fired up and vibrated badly, particulary from wheel wobble

So i did some googling only to find this is a common and often difficult problem tosolve

worse still i put the old wheel back and that was no better

I had upset the balance of nature

Have any of you guys had this embarrassment ? (no facetious remarks pls)

Yes. Just fix it.

My grinder has various bushes to make up the correct diameter of the wheel used. I ended up making new ones as they were not very good. All good now. Also if you can get hold of a truing diamond it can help.

Steve.

its not the radial run out I am concerned about as this can easily be sorted with a diamond tee bar dresser, its the side wobble that shocked me. Ive seen a dozen vids (most are old blow hard rubbish) but some have made serious attempts at the problem

Its not a trivial matter and took me by surprise

Is there any bushes in the centre or is it a perfect fit on the steel shaft.

Steve.

both wheels old and new came with delrin bushes 1/2"" for the wheel

gets me i can even reinstall the old wheel as it was, it has devloped a wobble which it never had before

cant figure how this has gone pear shaped

I replaced them as they came off. I am going to try a few more tricks tomorrow and get a dti on the job, make up new plates, cardboard washers, what a palaver. my m/c vibrates so badly its barely usable, no vibes without the stone btw.

this has never happened to me before but then i dont remember ever changing a grinding wheel.

My el cheapo grinder vibrated quite badly, so I bought a new wheel with 1.25" hole and made new washers, the one nearest the motor has a boss to fit the in the wheel, just a bit shorter than the wheel so the other washer clamps up. this new thick boss/washer has 2 grub screws to hold it to the shaft. All unbalance problems gone away. I cribbed the idea off a RJH Ferret grinder

As an aside ; are the bearings on the shaft starting to go, do they 'rumble' when you start the motor up?, it usually is one of the above reasons though.

George.

Hi George, no rumble, indeed the grinder hasnt had much use in 10 years

BUT I have a cunning plan which is painfully obvious and hasnt so far been suggested to me.

watch this space.

Thanks, Duncan, never thought of that solution. Will bear it in mind, should I ever have grinder trouble in future.

John

Hi Brian, if the retaining discs either side of the wheel are the pressed type, you may have inadvertently over tightened the nut and distorted them, if so you should replace them.

Regards Nick.

There may be a dynamic balance interaction between the two wheels. You could try moving the new wheel round the shaft, say 10 degrees at a time, to see if it makes any difference. I recall being taught this as an apprentice.

+1 for Duncans arrangement of integrated boss and flange. I did the same with very satisfactory results. I didn't use any grub screws, just the original outside flange and clampling nut. The major benefit of this arrangement is that the long hole, being a good fit on the spindle, holds the wheel nice and square and eliminates any wobble.

Peter

Hi Brian the inside washer holds the wheel square and I have made washers like Peters with a boss on the end that just slides over the wheel spindle and has a shoulder of a smaller diamiter to stop it being pushed on too far. The washer side should be the same diamiter as the original washer and relieved so that the outside 12 mm band grips the paper washer and wheel and doesn't stress the wheel.

David

Hi, you may wish to peruse this information.

Mounting the Wheel

Regards Nick.

I knew nothing about bench grinders so I typed, "Which bench grinder?" into Google and then bought a Metabo DS200.

's loverly.

but have you change a wheel yet?

which is the point of my OP, I was floating along then disaster

but I have a cunning plan which I am trying out just now