Hi all and happy new year ! I have an old Ingersoll rand bench grinder and looking to find a cbn wheel for it. It's a smaller machine and unfortunately do not have the original wheels to measure, but know its imperial sized. The wheel diameter is 6" and the bore size is 1/2" I'm assuming the width is 3/4 inch as a measure with calipers from the metal (cup ?) to the bolt is coming in around 18mm ish. Anyone know if a 3/4 inch wheel thickness be a standard size ? And know where I can purchase a cbn wheel with the dimensions as above ? The Axminster offering has a 25mm width and I wouldnt be able to fit the sides back on the machine at that thicknesss ! Thanks all for any advice.
Grinder wheel size confusion
- Thread starter Mel769
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When you search more widely for CBN wheels, the narrowest that appears is 1" wide. Amazon has a wide selection. Nothing comes up in any narrower width.
Have a good look at the machine and perhaps post some photos. If an available wheel will fit on the shaft of the grinder and tighten up safely, the guards can be extended so they do fit.
Another alternative, looking at some of the wheels available, would be to reduce the width of a 1" wheel. They appear to be made of aluminium and only have CBN abrasive on the cylindrical part. Hence, by turning from the inside towards the outside, the overall width could be reduced. That would also give the option of taking 1/4" off one side and nothing off the other through equal amounts off both sides so the available space is used to the best extent. The central boss of the wheel, that surrounds the shaft, can also be reduced in width if required.
Using the dimensions of an available 1" one, make a mock up out of MDF and see what needs to be removed or how the grinder needs to be altered to accommodate it. That will give you an idea if it is worth your time and effort to do so, compared with purchasing a different grinder.
Have a good look at the machine and perhaps post some photos. If an available wheel will fit on the shaft of the grinder and tighten up safely, the guards can be extended so they do fit.
Another alternative, looking at some of the wheels available, would be to reduce the width of a 1" wheel. They appear to be made of aluminium and only have CBN abrasive on the cylindrical part. Hence, by turning from the inside towards the outside, the overall width could be reduced. That would also give the option of taking 1/4" off one side and nothing off the other through equal amounts off both sides so the available space is used to the best extent. The central boss of the wheel, that surrounds the shaft, can also be reduced in width if required.
Using the dimensions of an available 1" one, make a mock up out of MDF and see what needs to be removed or how the grinder needs to be altered to accommodate it. That will give you an idea if it is worth your time and effort to do so, compared with purchasing a different grinder.
Phil Pascoe
Established Member
You could take off the guards, they are there mainly in case a stone fragments which of course a CBN wheel won't.
Okay so I cut a 3/4 inch blank from mdf and this confirms it should be this width. The tool rest slot is also 3/4". I could remove the side covers but would prefer not to as that would mean the tool rest would be no use. Also it's a nice grinder so would prefer the correct size cbn wheel. Hey-ho nothings ever simple is it with these new fangled sizes; if anyone can find a source of 3/4" thickness cbn wheels let me know pls !
Add 3mm either side of the wheel on the perimeter only and see if it touches anything. The 1" wheel is only 6mm wider than the 3/4" one and on the motor side this looks to be easily achievable.
Slot the holes in the outer guard and on the main part of the guard and it might move out 3mm (you only need 1.5mm extra on each slot).
If necessary, you could reduce the boss on a 1" wheel on the inboard side, which would shift the entire wheel to the left, and could fit in the space.
For the tool rest, either file out the slot in it to make it wider or make a new one (a short offcut of square or rectangular box section, with the bottom side cut off would be a good start and would have nice radiused corners).
Another, another option is to put a spacer between the guard and the body of the grinder so the entire guard moves to the right a little relative to the inner flange on the shaft.
Slot the holes in the outer guard and on the main part of the guard and it might move out 3mm (you only need 1.5mm extra on each slot).
If necessary, you could reduce the boss on a 1" wheel on the inboard side, which would shift the entire wheel to the left, and could fit in the space.
For the tool rest, either file out the slot in it to make it wider or make a new one (a short offcut of square or rectangular box section, with the bottom side cut off would be a good start and would have nice radiused corners).
Another, another option is to put a spacer between the guard and the body of the grinder so the entire guard moves to the right a little relative to the inner flange on the shaft.
Phill05
Established Member
You can pick-up CBN cup wheels in different shapes with reduced middle that fit your size of grinder I have two for my machine I found them on e-bay years ago.
Edit: eBay item number: 355561588399 as you would expect from China.
Edit: eBay item number: 355561588399 as you would expect from China.
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Do you mean the metal disks that sit each side of the wheel ?
Phill05
Established Member
Have a look at eBay item number:355561588399
Thinking about it ; I would probably need to change them disks (are they called cups) anyway even if I could find a 3/4" thick wheel, as the original cups rely on mating to the flat side; cbn wheels dont have dead flat sides anyway
They are called 'flanges'. They are used to give a sintered abrasive wheel made up of grains of material adequate support. There should always be a paper blotter between the flange and stone. For a solid body CBN wheel, they are not required and a simple spacer is acceptable.
Removing the inner flange and letting the CBN wheel abut the step in the shaft might move it over enough to fit between the guards.
There are very few new 150mm bench grinders that will come with a 25mm wide wheel as standard, so at least do some research before committing to that option.
Axminster describe theirs (which is 40mm) as 'wide stone' so that might help find an alternative:
https://www.axminstertools.com/axminster-workshop-aw1502wsg-wide-stone-grinder-230v-107824
This is useful reference material with regards to abrasive wheels and their mounting:
https://www.hse.gov.uk/pubns/priced/hsg17.pdf
Phill05
Established Member
Yes of course they have a flat sides to clamp up to your plates and nut on the shaft and you can put different spaces on for different shaft sizes
Thanks for these responses; I will get to it with my calipers and find out how much space the existing cups take up; if I can remove these and add spacers then this may give me the space I need ! I will report back this evening after tea ! Thanks that's great !
Jester129
Established Member
Why don't you get a strip of 1mm thick metal, say 30mm wide and fit it to the guard to make the guard 30mm wider? The easiest thing to do.
