Thread: Bench Grinder - what to look for???

If they both have similar power, and both fit the wheel you want, I would look at other features. The Bosch unit looks to have a more substantial workrest although it is hard to tell on the net. I'd want a grinder on which I could use a simple diamond wheel dresser, like this

https://guideimg.alibaba.com/images/...428_683294.jpg
.

Cal

What you plan to use the grinder to do: lathe chisels, bench planes and bench chisels?

What is your budget?

Regards from Perth

Derek

Originally Posted by derekcohen

Cal

What you plan to use the grinder to do: lathe chisels, bench planes and bench chisels?

What is your budget?

Regards from Perth

Derek

Thanks for the reply. Lathe tools mainly. planes and chisels I do by hand. Budget $200-$250. There seems to be more wheels available for 16mm arbour thus the question of what to go with. I don't want to end up with a grinder I can't get wheels for at a reasonable price.


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Cal, with lathes in mind, I would recommend that you read up about CBN wheels. They are not cheap to get into, but they last forever and so become cheap. They come in high grits, up to 350 grit I believe. The question is whether they will fit a cheaper machine with a 16mm arbor, or whether they need a full 19mm arbour. And whether the arbour is long enough to support a wide wheel.

Ditto what the power of the grinder needs to be (I reckon you need to aim for 1 hp). Ignore the tool rests that come with the machine - you will need to replace this anyway. None of the fitted tool rests are worth any time at all. Lathe tools need specific rests anyway.

Google CBN wheels on Youtube.

Regards from Perth

Derek

I wouldn't go for large arbor diameters as it will restrict what wheels you can purchase.
I have an old grinder with a 1" arbor and that is a PITA because a wheel with a 25mm hole won't fit so I have to by bigger and shim down.

16mm is fine for an 8" grinder.

With regards grinder power, unlike most machine motors, grinders are often rated for their input power rather than their output power which is typically 30-40% less than input power.
The only grinder I have found that this does not apply to is the Abbott & Ashby which is rated at 600W and outputs a true 600W.
Some grinders I tested with supposed 1HP rating were not even capable of outputting 1/2 HP or real work.

I second what Derek says about CBN wheels.
Once you get one you'll rarely go back to other wheels.

Thank you both for the feedback. Great info! So looking at the CBN wheels they have an arbour size of 1" or 5/8, since 5/8 is 15.875mm will it fit a 16mm arbour or do I need to go 1" and bush it down to 16mm?


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Hi Cal

A correction: 16mm is OK, is what I should have said. My grinder is Imperial, and 5/8" and this confused me. There is a difference between 16mm and 5/8" - they do not match one another I am told. The slight difference in size is significant in practice. Bob will know better than I. What I had meant to warn against is an arbour of 1/2" or 12.5mm - they may not have enough rigidity.

Most CBN wheels may have a 1" arbour (mine do) but they come with reducers to 5/8". One of the great things about these wheels is that they are so well balanced.

Note that most, if not almost all, the machines on sale in Oz are now metric, not Imperial, so 16mm is what you will likely find.

Regards from Perth

Derek

Ok, good. Carroll's Woodcraft have two different brands of wheels. The Vicmarc ones are available with 16mm bushing so it looks like that is the way to go.
Who would have thought buying a grinder would be so hard??


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Originally Posted by Cal

Ok, good. Carroll's Woodcraft have two different brands of wheels. The Vicmarc ones are available with 16mm bushing so it looks like that is the way to go.
Who would have thought buying a grinder would be so hard??

Theres more choice than we have described, like 3Phase and variable speed, but I guessed you weren't interested in those spaces. )

Originally Posted by BobL

Theres more choice than we have described, like 3Phase and variable speed, but I guessed you weren't interested in those spaces. )

Your right! I don't have 3 phase in the shed and working on limited budget too! [emoji853]


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To start you of before you go buying a grinder that you still have to buy wheels for we have the Vicmarc Slow Speed Bench grinder which has the 32mm wide wheels and are white aluminium oxide.

Why go for this against the others that have been mentioned, the main answer is speed.

You are going to use it for sharpening not grinding so the slow speed is all you need 1500rpm.

As it comes with a 60g and 120g wheel there is no need to get the CBN wheels straight away.

Put the money you were going to spend on the CBN wheels into a good sharpening set up like the Tormek BGM 100 and jigs.

When you wear out the white wheels then upgrade to the CBN wheels.

In regards to the the CBN wheels the main difference is that the Vicmarc wheels have a 40mm wide flat on the side of the wheel which a lot find a great asset.

Thanks Jim, that's a great response and it makes a lot of sense! I don't plan on using it for anything other than sharpening. I will have to save my pennies for it though. I have some vouchers for Mitre 10, I was going to by a grinder with the vouchers. There goes that idea!

The VM100 chuck I purchased from you is great by the way!

I noticed the flat on the side of the Vimarc wheels, great idea.

I get back to Geelong regularly to see my kids, will call in when I'm all cashed up! Thanks for your advice.




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