Thread: Bench Grinder options - 150mm

keen to hear this as well.

except i just want to rip the wheels off straight away and put a wire wheel and buffing wheel on them instead.

The A&A (Abbot& Ashby) would be the better choice without exception.

Originally Posted by China

The A&A (Abbot& Ashby) would be the better choice without exception.

Better motor / bearings or brand reputation?
370w vs A&A's 280w? Most likely their rated input power, but still a substantial difference.

For yuz, there is no indication of what you want the unit to do, but a 6 inch unit has a low surface speed compared to 8in or 10in units at the same RPM. To compensate the user tends to push harder and bog the motor down further. I suggest much patience would be handy if the intended tasks involve moving much metal.

For haveabeer, buffing with small buffing wheels is also a task requiring a lot of patience compared to running a machine with a more substantial wheel. I was polishing and buffing commercially for a number of years, and using 12-16inch buffs on 2850 RPM polishing lathes. The only time we ran buffs smaller than 10inch with was if we had to get into very tight corners for touch ups etc, and then we used handheld barrel polishers around 10,000RPM. Buffing generally requires high surface speeds to melt the compound onto the surface and break it up to ultrafine grits to get a decent polished finish. If you need to run smallish buffs, I would suggest an angle grinder set in a mounting jig of some sort to get the surface speed up to workable levels. I would never consider operating a wire wheel and a buffing wheel in close proximity, too much risk of the buffing wheel being contaminated by the detritus coming off the wire wheel or work being brushed, and scratching up the stuff being buffed at a later stage. We used to have separate belts, wheels, buffs and compounds for different metals, and keep each group in separate lockers outside the polishing room specifically to avoid cross contamination.

Originally Posted by yuz

Better motor / bearings or brand reputation?
370w vs A&A's 280w? Most likely their rated input power, but still a substantial difference.

The 280W for the AA is output power ,input for the ATBG280/6 is 420W.

Expect for vey light work my experience with 6" grinders has usually been disappointing. Used the first one I bought for a few weeks and then went a bought an 8". I donated the 6" to the mens shed and they use it just to sharpen small drill bits. I have 2 x 1HP 3P grinders on a VFD, and an older 680W A&A and that is a really good grinder.

I would never consider operating a wire wheel and a buffing wheel in close proximity, too much risk of the buffing wheel being contaminated by the detritus coming off the wire wheel or work being brushed, and scratching up the stuff being buffed at a later stage. We used to have separate belts, wheels, buffs and compounds for different metals, and keep each group in separate lockers outside the polishing room specifically to avoid cross contamination.

I agree about using separate wheel and belts and have my wire wheel on one side of a bench grinder but as they are easily mounted/removed I only put my buffing wheels on the other when I need them.

Originally Posted by malb

For yuz, there is no indication of what you want the unit to do, but a 6 inch unit has a low surface speed compared to 8in or 10in units at the same RPM. To compensate the user tends to push harder and bog the motor down further. I suggest much patience would be handy if the intended tasks involve moving much metal.

For haveabeer, buffing with small buffing wheels is also a task requiring a lot of patience compared to running a machine with a more substantial wheel. I was polishing and buffing commercially for a number of years, and using 12-16inch buffs on 2850 RPM polishing lathes. The only time we ran buffs smaller than 10inch with was if we had to get into very tight corners for touch ups etc, and then we used handheld barrel polishers around 10,000RPM. Buffing generally requires high surface speeds to melt the compound onto the surface and break it up to ultrafine grits to get a decent polished finish. If you need to run smallish buffs, I would suggest an angle grinder set in a mounting jig of some sort to get the surface speed up to workable levels. I would never consider operating a wire wheel and a buffing wheel in close proximity, too much risk of the buffing wheel being contaminated by the detritus coming off the wire wheel or work being brushed, and scratching up the stuff being buffed at a later stage. We used to have separate belts, wheels, buffs and compounds for different metals, and keep each group in separate lockers outside the polishing room specifically to avoid cross contamination.

alot of good info there, thanks

One problem with using an angle grinder (AG) is finding wheels/mops that fit AGs AND will safely hold together at the much higher speeds.

Here's is a chart showing linear speeds for a range of bench and angle grinder wheel sizes.

Shown are the typical RPMs and bench grinder and AG diameters

Screen Shot 2020-12-10 at 7.48.48 am.png

Starting with Malbs 12 - 16" industrial polishers at 2850 RPM gives a desirable linear speed of 22 - 30 m/s .

A 6" bench grinder at 2850 rpm produces only 11 m/s, an 8" is slightly better at 15 m/s
These of course are maximums because as the wheels wear down, the speeds will drop.
The other problem with small grinders is that because they are slower at polishing the operator tends to push harder but that just slows down the grinder.

Angle grinders all produce over 30 m/s but I doubt you will find a buffing wheel that will hold together at those speeds. The typical Josco buffing wheels are rated at no more than 3000 rpm and use hex shanks so designed to fit into drill chucks. Aside from that I find the noise made by angle grinders abominable.

I have tried a standard 8" Josco and H&F buffing wheels on my 1HP 3P VFD driven bench grinders running at 3600 rpm (19 m/s) and was pleased to see it held together and it's faster and better at polishing than running it at 2850 rpm, but it also wears the wheel faster. I can run those grinders up to 4200 rpm which would produce the same as Malbs 12" at 2850 rpm (22 m/s) but I'm not sure the wheel would hold together.

Over the last few years I found it's swings and roundabouts. I can understand that commercial operations need to minimise polishing time but my time is cheap. Higher speeds definitely polishes better/faster but also wears the standard wheels faster so now unless I'm doing something special I usually run the 8" wheels at 3000 pm.

I can appreciate strict space limitations, but I have to ask, is it 100% no chance on a larger unit? Width/height-wise, the A&A 200mm is 100mm wider and 70mm taller (shipping dimensions though), the biggest benefit in my eyes is a better tool to mount a Multitool linisher on (apologies, I absolutely love that attachment, it accounts for 90% of my grinder use)

Originally Posted by LordBug

I can appreciate strict space limitations, but I have to ask, is it 100% no chance on a larger unit? Width/height-wise, the A&A 200mm is 100mm wider and 70mm taller (shipping dimensions though), the biggest benefit in my eyes is a better tool to mount a Multitool linisher on (apologies, I absolutely love that attachment, it accounts for 90% of my grinder use)

I'll go and size them up if they're on display. It's just to maintain drill bits / chisels - small stuff really (@Malb).
The grinder will be stored away, hence sizing considerations. As for attachments - very tempting but then I'll need a second job and a larger workshop
So I'm aiming at a 150mm unit with the most grunt. Put it this way - so far I've survived with a 80mm Workzone "grinder"!

sorry to hijacks Yuz thread

any opionins between these two?
ABBOTT & ASHBY 600W 8inch Disc & 50x915mm Belt Bench Grinder PO362PLUS8 | Total Tools
76346-abbott-ashby-200mm-industrial-bench-grinder-po362plus8-hero_1.jpg



ITM 200mm Bench Grinder with PO362 Multi Tool Attachment PO362200 | Total Tools
145906-multitool-po362-attachment-suits-tm400-200-itm-200mm-bench-grinder-po362200-PROMO.jpg





I can't find that specific model of the Abbot for sale at total tools but the two other Abbot 200mm grinders are $230 - $250, i guess its a bit of a "is the linishing attachment worth the extra $200". the attachment is only $269 to buy separately. i think at this point i will consider just buying an 8" grinder and look at attachments later

Originally Posted by havabeer69

I can't find that specific model of the Abbot for sale at total tools but the two other Abbot 200mm grinders are $230 - $250, i guess its a bit of a "is the linishing attachment worth the extra $200".

I reckon it is. For a start its far quicker to change belts with different grits than it is to change grinder wheels.

The linishing att. is something that once you start using it you will wonder how you ever survived without one.

Originally Posted by havabeer69

any opionins between these two?

I can't find that specific model of the Abbot for sale at total tools but the two other Abbot 200mm grinders are $230 - $250, i guess its a bit of a "is the linishing attachment worth the extra $200". the attachment is only $269 to buy separately. i think at this point i will consider just buying an 8" grinder and look at attachments later

My personal vote is the Abbott & Ashby.
You could always see if Machinery House do price matching, they've got theirs listed at $550 - G157 - PLUS-8 Industrial Bench Grinder with Linisher | Hare & Forbes Machineryhouse