Slow Speed Grinder?

Everyone in our class had to sharpen a plane blade and a chisel and were graded on it. I don't remember anyone failing. It is not some supernatural ability, just a simple skill any boy could learn in a fairly short time.

You’re obviously much younger than me. The only bench grinder in my School was in the metalwork shop. The woodwork shop used a large flat rotating oil stone for plane blades and chisels. A friend of mine is a technician at a school and they still use one of these, a Viceroy Sharpedge. You get a traditional flat grind with it not the hollow grind you get with most modern grinders. The Japanese sell a much smaller unit that uses water instead.

Re the "Japanese" machine, the similar ones I have seen do not recirculate the water and, more importantly, I had doubts about their electrical safety. The rotating stone seems similar in composition to the conventional Japanese water stone.

They are certainly capable of putting a keen edge on chisels, etc and a planer blade attachment is available.

The same is true of higher mathematics. Integral Calculus is also 'a simple skill any boy could learn in a fairly short time!'

A schoolfriend soaked up languages like a sponge. By age 13 he was a dead cert for O-Level French, so he effortlessly switched to German. Being in the arty stream, he did Latin too, and later volunteered for 1 hour per week Classical Greek as an extra lesson.

He was amazed that others found languages difficult. Truth is aptitude and talent matter, and we're all different. Poor chap was far worse at maths and woodwork than me!

Dave

I don't think calculus and grinding an angle on a piece of steel are any kind of equivalent. Grinding a blade is perhaps more comparable to long division. Using a lathe might be more comparable in complexity and skill level to calculus. But even then, every boy in school got to use a lathe in a basic manner to make a centre punch and a hammer and bits and pieces. Only about 10 per cent of the students, those in the top academic "stream", got to do calculus. The rest did a simpler math course.

People seem to get obsessed with sharpening. Huge number of Youtube videos on the subject and snake oil salesmen with their products. Once you have done with chisels move on to knives and yet more of it. No time for actually using the things.

It's a particularly good demonstration of Perfect being the enemy of Good Enough...

Once something is sharp enough to cut [thing you want to cut] then any further effort is actually just wasteful... I don't need to shave with my handplane blade, and will never be called upon to slice sashimi with a wood chisel, so why would I behave like I do?

Unfortunately lots of people getting into woodworking as a hobby in later life do seem to get caught up on it and taken for a ride by aforementioned snake oil salesmen...

I've just got back from a couple of days away, so I may have missed the point of this thread.. "Clickspring" on YouTube has recently published a video of him using a slow-speed grinder to put fine, accurate edges on an HSS tool for his Rose engine. His is used in a horizontal plane and is considerably slower than the quoted figures above. Similarly, Stefan Gotteswinter showed his version of a slow speed grinder for final finished edges on a carbide cutter in another YT video. Both worth watching in my view.

Clickspring clip

Stefan Gotteswinter video

Both seem to use similar grinding discs held magnetically to the drive flange .

Almost certainly intended to perform a different job to the ones for which the likes of the Axminster grinder are aimed.

John

Edit:  Misc. spelling etc.

Edited By John Hinkley on 07/12/2022 19:57:02

Clickspring is using a GRS Graver Hone, known to stone setters and engravers everywhere, but only owned by those fortunate enough to have a spare four figure sum burning a hole in their pocket. And that excludes the diamond discs.

Stefan's honing machine is a shop-made device, owned by those fortunate enough to have the talent and workshop necessary to make one.

Yes, the Axminster grinder isn't really for honing or grinding small cutters, but for general grinding of HSS tools.

Edited By Bill Phinn on 07/12/2022 20:18:04

All rather depends on what you mean by "slow speed grinder" doesn't it? I reckon all the responses are valid to some degree or other.

John

To update my post on page 1 of this thread, as well as my own thread about diamond and CBN wheels, I was contacted by Axminster Tools today. They took both my slow speed grinder and the two CBN wheels I'd ended up with back to base three weeks ago after I'd been unable to cure the lateral runout problem with the CBN wheels when fitted to the new grinder. I won't go into what remedies I tried here, but they were numerous.

Gratifyingly [in a way], Axminster Tools told me that their technical staff had been unable to cure the lateral runout either, and not just with my wheels on my grinder but with all the CBN wheels they have in stock on several examples of the same type of grinder. They concluded that the wheels, the purpose-made bushes for mounting the wheels, and the grinder are not compatible as things stand, and they are currently working on incorporating some design changes to newer versions of the wheels, bushes and grinder. They couldn't or wouldn't elaborate on what they feel the root of the incompatibility is.

It appears from recent reviews of the grinder on Axminster's own site that I'm not the only buyer who was unable to cure wheel wobble when fitting CBN wheels to it.

A full refund is currently being processed for my purchases.

.

Sounds like the best-possible outcome, Bill

MichaelG.

[ digression ]

This page from Eternal Tools may be of interest to graver-users with reasonably deep pockets.

**LINK**

https://www.eternaltools.com/stones-sharpeners/small-diamond-grinding-wheels

I cannot yet justify the switch to carbide gravers, myself

MichaelG.

Belatedly, but I did not see this reply before: I forgot to mention we rubbed the plane blades on a bench oil stone after initial grinding on the bench grinder. This put a narrow, flat, finely honed face along the edge of the hollow ground area, achieving the same result as sharpening on a flat stone as you describe. We were graded on A. How well we had made the initial hollow ground surface on the bench grinder and B. How well we had oilstoned the small flat surface to form the final cutting edge. I imagine this was the way plane blades were sharpened on the job by carpenters and cabinetmakers since time immemorial as rotating flat stone machines were not something most small workshops would have had.

I bought a Taylor Hobson cutter grinder for very little and made an adjustable tool rest to replace the original cutter holder. It has a diamond wheel for carbide tooling and a white aloxite cup wheel I use on HSS tools.

David

My plane irons and wood chisels never go near a grindstone. I use diamond whetstones followed by metal polish on leather as a final hone. Slow speed grinders are really only necessary for turning gouges where very frequent sharpening is required and a fine finish is not that important. If you cut joints by hand especially fancy dovetails then a razor edge is a distinct advantage. If you only need a general purpose jobbing chisel then not so much.

regards Martin

I'm coming to this thread late, but the OP asked what's the point of slow speed grinders for woodturners?

I am a model engineer and a woodturner and have a Creusen slow speed 6" grinder with two 40mm wheels and like it very much.

The reason for me is that I can touch up my tools in a quick but controlled way. I tend to use a homemade jig system for all of my w/t gouges and this allows me to resharpen half way through turning something. If turning exotic and abrasive timber it may be necessary to be resharpening every few minutes.

A standard grinder would work, but it's very easy with small gouges and fine edges to blue the HSS. In theory this does no harm but IMO it's better not to if you can avoid it.

A 60 grit wheel on one side is still quick enough for rough shaping and a 120 grit fine wheel is great for frequent touching up with minimal loss of steel. The Creusen is very nicely balanced and quiet.