Should I throw my Abbott & Ashby out or persist with trying to service it?

Happy I got to spend some time in the garage yesterday after months of being too busy elsewhere or having to deal with rodents and rodent damage in the garage.

Sad to figure out that my bench grinder seems to actually be kaput ... I put brand new wheels on it with steel bearings and it still vibrates unacceptably.

What else can I try?

Can I measure shaft wobble with the grinder unloaded, and to what end? I have a digital micrometer but don't think it'll respond fast enough.

Any point disassembling the machine? What could I expect to do? I've already worked on the base.

Nathanael, can you return it, or contact the seller or agent? That's what I would do. It is unusable, and should be replaced if new.

Regards from Perth

Derek

First I would remove the wheels and check that the shaft has no run out and that you have not damaged the bearings when installing them if not then it is the wheels or flanges, when ever I purchase a grinder if it has cheep pressed metal flanges I discard the and make solid turn items, (you can also purchase these) if the flanges are ok the it only leaves the wheels, in most cases on a bench grinder you can remedy this by dressing the the wheels

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Originally Posted by NathanaelBC

Happy I got to spend some time in the garage yesterday after months of being too busy elsewhere or having to deal with rodents and rodent damage in the garage.
Sad to figure out that my bench grinder seems to actually be kaput ... I put brand new wheels on it with steel bearings and it still vibrates unacceptably.

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Most brand new wheels still need dressing.

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Can I measure shaft wobble with the grinder unloaded, and to what end? I have a digital micrometer but don't think it'll respond fast enough.

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A micrometer won't usually have enough resolution and are hard to use to measure run out.
What you really need is a dial gauge preferably one on a magnetic base.
Most metal turners and machinists will have one of these to set up their machines.

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Any point disassembling the machine? What could I expect to do? I've already worked on the base.

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Definitely check the shaft run out first

It's about 20 years old, but has been little used for much of that time.

I spent a lot of time trying to dress the previous wheels but the vibration made it near impossible so I'm not in a hurry to ruin the new wheels.

Thanks I'll figure out how to test the shaft run-out, find a local machinist.

BTW it's not a micrometer it's a digital dial gauge but still don't think it'd be of much use on a shaft at 3,000 rpm

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Originally Posted by NathanaelBC

BTW it's not a micrometer it's a digital dial gauge but still don't think it'd be of much use on a shaft at 3,000 rpm

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You don't need to run the grinder to test the run out.

Have you dressed the new wheels?
Does it vibrate or can you see the shafts wobble when you run it without wheels?

Before you run too far down the rat hole finding machinists and buying new precision measuring equipment....

Price out a new bench grinder... You will be time and money ahead replacing it rather than spending more $$$ on it if it's kaput....

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Originally Posted by truckjohn

Does it vibrate or can you see the shafts wobble when you run it without wheels?

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It seems fine without wheels, only measured 0.01 mm wobble with the gauge rotating unpowered.

Most likely it is the wheels are they a known brand or ebay specials, do the wheels have blotters ( thick paper Labels )on them, next thing to check is the flanges are they bent or distorted

:whs:

Also, when you fit a wheel it's a good idea to use a marker on the wheel and axle so you have a reference point.

If it vibrates, loosen the wheel, turn it 30 degress, tighten and retry. Take note of whether the vibration seems to be the same, worse or less. Often by repeating this process you'll find a sweet spot where minimal dressing is required to get it balanced nicely.

With an unknown grinder I'd take it back to bare axles and balance each individual wheel/mop/whatever before moving on to the next. I have a beloved A&A grinder where a wheel self-destructed and I couldn't get the replacement to run true no matter what I did... like you I thought it'd bent the shaft.

Until I realised that even without the new wheel the vibration was pretty horrific; the shaking from the destruction had thrown the other wheel out of true as well! :doh: If only I'd spun it up before replacing the bad wheel I'd have saved myself some headachy drama. :rolleyes:

Well, I stuck with it ... kept at it with the Tru-n-Dress and was just about to give up when suddenly the vibration ceased like I managed to true it enough to cross a tipping point. Was quite weird. I suspect what I've been doing wrong is having a wheel mounted on the other side so this time I just had the one wheel mounted and was more precise with the Geiger, using double-sided tape to attach it to the mitre slide on the tool rest though still the tape slipped a bit so not a perfect set up but got the job done.

Now I have to clean up that horrid white aluminium oxide grit that's all over everything ...

... but at least I've avoided spending $200+ on a new grinder.

I suspect what's happened is that when I took the grinder out of storage a couple years ago and replaced the old grey wheels with the white ones that the new ones have always been troublesome, with excessive vibration causing skipping and chipping of plane blades etc so these white ones I've been using are just poor quality in terms of how much they need to be trued up.

I'd be interested to know who else uses these wheels and what their experience has been with them:

https://www.timbecon.com.au/sharpeni...grinder-wheels

Now to swap it out for the new coarse wheel and true that, then see how they run together.

I've had one of those timbecon wheels and for about 2 years it worked very well but eventually due to inexperience on my part it became a tad rounded and when I tried to dress the wheel I did it too aggressively and this made it go out of round and vibrate. I was not skilled enough to get it back to round and eventually it got so bad I had to chuckle it away. The same thing happened to my first Blue Max wheel which I used to bulk grind "stuff".

If a wheel is badly out of round it is very difficult to dress it back to a balanced state. The tendency is to push even harder on the wheel with a dressing stick but that makes it even worse. Instead one must try to take as little off as possible to prevent the wheel from bouncing the dressing stick.

I have used many Abrasiflex wheels and never had any issues