Newbie bench grinder question

[Apache_sim]

I have just started woodturning and having used my brand new gouges and skews I thought I would turn my hand to sharpening them. I bought a Record 8 in grinder with a white stone. When I run it the stone is clearly not running true.
I estimate it to be about 1 mm. Is this an issue if I try to sharpen the tools? The shop have said To bring it back and they will look at it.
Thanks

 

[MMUK]

First thing I would check is that it is mounted square on the shaft and backing washers

 

[Spindle]

Hi

Which way is the 'out of true', axial or radial? Does the grinder vibrate due to the 'out of true'? What is the grey wheel like?

Regards Mick

 

[pip1954]

hi undo stone rotate and tighten if it still not right take it back let them sort it
cheers
pip

 

[Apache_sim]

I think it is out of true in both directions. As I rotate the stone by hand I can see the inside edge wobbling.
Also radially out by about millimetre or so.

 

[Rhossydd]

Is this an issue if I try to sharpen the tools? The shop have said To bring it back and they will look at it.

Yes, it will be an issue if the wheel isn't turning true.
Just get it replaced by the dealer if it's faulty. You shouldn't have to put up with fixing new kit.

 

[KimG]

I had a new one (same machine) it was out, I sent it back and they (Record) sent me a new one that they bench tested, it was still out, i.e. you could see a small wobble and the machine vibrated, I decided that this was probably as good as it got. I had bolted the machine down to the bench, this circumvented the rubber shock absorbers from properly performing their function, so I made the bolts act as locators and left the rubber feet to do their job properly, now, although there is an element of vibration, the wheel acts like a gyro and stabilises at full speed and the rubber feet take up the slight out of true movement, I have no problem sharpening with it.

From my own experience with this and another smaller grinder, getting a wheel to run dead true is a frustrating and time consuming exercise best avoided if you can reach a happy compromise by another means.

 

[Grahamshed]

Hey Kim
Off topic but I just had a look at your blog. That pixie table lamp looks fantastic.

 

[Spindle]

I think it is out of true in both directions. As I rotate the stone by hand I can see the inside edge wobbling.

Hi

I'd sort it myself but if you're not confident to do this I suggest you return it.

Numerals in parenthesis refer to page 15 of the manual.

Remove the wheel cover, (6), and the offending wheel - if this is the white wheel it will have a left hand thread on the spindle, (grey is normal right hand thread).

Examine the faces of the flanges, (10), ensuring they are free from damage, distrortion, burrs and debris.

Examine the 'blotting paper' stone washers, (11), ensuring they are intact and free of debris

Examine the mounting faces and bore of the wheel for damage and debris.

Examine the shaft for damage, debris and burrs

If all OK reassemble the wheel loosely onto the shaft, ensuring the 'blotters' are in place and nip up the nut just enough to retain the wheel.

Slowly spin the grinder from the other wheel and observe the subject wheel - if it still has run out move the wheel about 30 degrees on the spindle and try again - repeat until the run out is acceptable - tighten the securing nut, (8 or 42), and confirm run out is acceptable. Refit the wheel cover.

If the above does not bring the radial run out to an acceptable level the wheel surface would ideally need to be dressed, I have the tooling to do this but if you don't and the run out is less than 1mm and not causing too much vibration you could use the wheel and it will 'dress' itself in use.

If the axial run out is still an issue, > 1mm, and causing vibration I'd send it back. It is possible to 'fine tune' the 'blotters' but I wouldn't recommend you do it.

Regards Mick

 

[CHJ]

Quite often it is the pressed steel clamping washers that are out of true and this error is accentuated by the stones greater diameter.

Easy to sort out with the purchase of some machined as opposed to pressed wheel clamp washers or skim the pressed ones yourself if you have metal lathe facilities, but a right pain to resolve if you don't and should not be needed anyway on a new machine.

If the out of true is very minor then dressing the wheel with a single point diamond should reduce the problem at the expense of a little wheel diameter and thickness.

 

[Spindle]

Hi Chas

The flanges on the Record Power grinder are of substantial size, (12mm thick), and machined - not pressed

Regards Mick

 

[woodfarmer]

If it is not loose, I would dress it with a "devil stone" £3.50 or thereabouts from Axminster. You will need to re dress your wheel from time to time anyway as it wears.

 

[CHJ]

Hi Chas

The flanges on the Record Power grinder are of substantial size, (12mm thick), and machined - not pressed

Regards Mick

Then there is absolutely no question, machine or wheels at least, not fit for purpose.

I've had instances of wheels moving in transportation due to heavy handling on older machines where the wheels had previously been dressed in situ but new wheels on new machine should in my opinion be good to go all bar very minor dressing.

 

[parvum]

Hi I had exactly the same issue with this bench grinder. Mine was fitted with two 40mm white wheels and it walked around at full speed. The vibration at low speed, as it wound down was excessive. On detailed examination several faults became apparent:
1 The wheels were not round. no great problem dressing them with a "T" bar diamond dresser, a normal routine easy job fixed that.
2 the holes in the middle of the stones fitted the shaft like a banana waving in the Albert Hall.Again it is the washers that locate and secure the stone ,not the fit to the shaft. A bit of fiddling got the stones rotating square to the shaft. This is tedious but not difficult and only needs to be done if the stone has been removed/replaced.
3 The most serious and inexcusable fault was that the bore of the washers was not square to the face of the washers, I am lucky to have a metalworking lathe and a skim fixed this.
In short this piece of kit has been manufactured down to a price and selective assembly is not applied, most of them are "OK" some are nasty, it appears that we , along with others got nasty ones and need fettling before being fit for purpose. For initial correction after dealing with any side to side axial wobble ( Micro pore surgical tape wound onto the spindle works well for dealing with major slop) The diamond dressing tool shaped like the letter T available from Axminster etc works well for me, easy to hold square to the wheel and cuts rather than battering the wheel to shape. Above all make sure that the paper washers are not cut through, that they are in place and do not over tighten the nuts and never never run the beast with the guards off a stone disintegrating at high speed will throw fragments with easily enough energy to change you for good if they hit you anywhere.
Once sorted it sharpens pretty well, good luck with yours

regards

Paul

 

[SVB]

I had similar issues with a record grinder. Record sent a total of 4 new white stones before one was acceptable. Ended up giving up and buying a more expensive crusen unit that is a dream.

EDIT:

No relation to seller but just seen this in FOR SALE section:

https://www.ukworkshop.co.uk/forums/creusen-powerline-grinder-with-stand-t76243.html

Not the slow speed spec version but at the price offered I'd bite his arm off if I were you!

Simon.