Sorby Edge Pro sharpening system - and current views?

[Trafalgar]

Yep. Tage Frid ground his chisels (in fact only a couple used mainly for mallet-driven work) on a belt sander with a worn belt with the machine in a vice upside down. He often used these straight off the sander, like some turners use their HSS tools straight off the grinder (HSS tolerates grinding to the edge of course).

 

[Glynne]

Thank you both for your replies.
Apologies if I'm being more obtuse than normal this morning, but I am still not quite clear.

I'm now with CStanford regarding the hollow grind and how this will "self jig" when honing - assuming you hone on a flat surface or a much larger wheel (i.e only the edge and heel of the face will make contact with the honing surface). A smaller radius would mean taking less metal off the edge when honing as you would get a steeper edge so I'm still following to this point. If you aren't honing on a flat or larger radius surface then I'm lost again sorry.

I'm with Jacob in terms of needing to jig the hollow grind (which I personally do), but then I'm lost again. If Jacob's view is about the need to use a jig or not, then for me that is a separate debate which I think we've had before (many times) and is somewhere I don't want to go.

So if my assumptions so far are correct (ha!), the benefits of a hollow grind using a smaller diameter wheel are around being easier to hone (removing less metal and therefore less time) although the cutting edge will be weaker than a flat or convex grind by virtue of the amount of metal behind the edge?

Sorry if this is all second nature to most people but, apart from the jigs / no jigs debate, I find it really useful to understand the logic behind different points of view.

 

[Trafalgar]

To make sure I've been clear: once the tool is in use, one hollow grinds to just behind the honed edge, not all the way to the edge.

It's easy enough to see that when grinding a thin, standard plane iron like a Stanley or Record that a larger diameter wheel will produce a shallower hollow and tend to grind all the way to the edge. A 6" wheel, which won't stay 6" for all that long produces a deeper hollow and it's easier to grind 'between the lines' of the honed edge and the heel established in earlier grinding. I have chisels whose edges haven't seen a grinder for years, yet they're perfectly hollow ground and see the grinder quite frequently. Same with plane irons.

If one regularly grinds to the edge, when the edge is not nicked, they are needlessly shortening the life of the tool and have, again, misunderstood the purpose of the procedure.

If one hones on the grind then you have a very convenient jig that makes freehand sharpening much easier. A slight lift to make an edge a little more durable is always an option but the starting point is always the 'click' of registering the cutter on the hollow grind to start. The process can be done practically blindfolded, going by nothing but feel and sound.

I don't really buy into grinding without a tool rest. They all come with one, some better than others, but something is better than nothing.

 

[Corneel]

In the old days when they used these large sandstone grinders, they would often grind freehand without a rest.

The weakening of the edge through the hollow gind is imaginary. The hollow from a 6" wheel is really too shallow to cause much weakening and in daily practice you won't find a difference. I lift the chisel on the final polishing stone anyway, increasing the angle at the edge and making it somewhat sturdier. The chisel I have been using to chop big mortices in beech (bench plane making) the last couple of weeks has a grind around 25 degrees, and is honed only slightly steeper. It holds up very well.

I can see how a flat or convex bevel is usefull when you ride the bevel on a lathe, but I have no experience with these things.

 

[Random Orbital Bob]

Given this thread is focused on the
relevance of the pro edge to Woodturning tools I'll add a "reality" check for turners that might have got derailed in the minutiae of hollow ground honing. That process is excellent for producing a superbly refined edge. Useful for hand planing difficult grain patterns in sophisticated woods like curly maple etc. That beautifully refined edge will last about half a pico second when presented to fast spinning wood and is therefore completely irrelevant to all but the most careful and fussy finish cuts in wood turning. Dare I stick my neck out and say it is in fact completely irrelevant!

I appreciate the response was to answer a specific question but just in case newer turners are now under the impression that using a grind that reaches the end of their chisel will render it useless from "metal erosion" in about a fortnight, think again

I have a roughing gouge inherited from my Father, made of carbon steel (meaning softer than HSS and therefore MORE prone to erosion from sharpening up to the edge. It probably gets sharpened more frequently than any other tool and I guess it's been going for about 40 years now (not continuously obviously). It has more than half its original tool steel poking out the handle! If not 3/4 in fact

So tails of rapidly disappearing expensive gouges are grossly exaggerated, functioning without reference to scale and frequency, both which, when applied render the practice a pointless waste of time. Use your pro edge as it says in the manual and reserve your fine honing for the job it was intended ie fine Bench work with plane irons and bench chisels

 

[Glynne]

Thanks Bob, you've answered my next question.
Obviously not clear from my posts but I was more interested in the suitability for turning tools as I've just about given up on the Tormek and was going to revert to the 6" grinder.
I do use the Sorby fingernail jig and I assume you can use this or something similar on the edge Pro.

 

[Random Orbital Bob]

Deja vu I think Glynne

I have a Tormek too and I also got very frustrated at the plethora of jigs and consequential setup time for all the different geometries of turning tools. In the end I plumped for a proedge and its revolutionised the speed and simplicity of keeping them sharp. I can also regrind a profile now in HSS without having to have my fingers amputated from "Tormek soreness".

And yes the elliptical grinding jig in use on the proedge is in fact not just like the Tormek jig, it IS the Tormek jig. Sorby licence it from Tormek who own the patent

 

[Random Orbital Bob]

I should add I've had the proedge for nearly 2 years now and remarkably, none of my chisels have disappeared. I'm unsure of Mr Stanford's economic standing but I think one new roughing gouge every 50 years for the sake of expediency is a price I'm prepared to pay. Though I accept that of course I don't "understand" sharpening

 

[CHJ]

One thing a ProEdge does do as far as using the Tormek Jigs is to reduce considerably the variation in setting angles required.

On a wheel grinder, the jigs have to take into account the contact position an a circular substrate that moves the angle of attack of the abrasive as the locus changes.

On a linisher (ProEdge) although the locus changes the angle of attack of the abrasive is a constant and therefore removes one very significant variable when forming wings on gouges.

Having recently joined the club with the acquisition of a used ProEdge and done a bit of my usual fettling to get it to do what I want rather than what the written word tells me I should want, I've reduced my jig variations by about 70% to achieve as near as no matter the same (my preferred) profiles.

• 
  1. Tormek profile jigs all set at the same setting* (Needed two pre-set at differing crank angle before as per Tormek system)
  2. Tool projection from jig face reduced to one setting, I had three as per. Tormek & Sorby Proset method.
  3. I use the Three hole locations in the Sorby Long Grind pivot block to control the gouge nose angle (not the proset).

* allows a more positive and easier extension setting than the Proset method.

Have I noticed a difference in Flat bevel as opposed to Concave off the wheel? In longevity of edge No, in subtle difference in presentation Yes, I'd be pushed to try and explain it, mostly felt in the smoothness of edge engagement on bowl internals, but there are so many variables of wood density, grain orientation etc. I doubt anybody could quantify it other than in theory.

 

[AJB Temple]

Since I started this thread I will chuck in a dimension or two here.

I was interested in the sorby linisher mainly because I want to sharpen turning tools without a lot of hassle. Having used the Tormek and other similar tools, I think set up for consistent grind of a variety of different profiles (such as roughing gouge, fingernail profile single gouge etc) is annoying. The gouges are relatively cheap in the overall scheme of things and I think it highly unlikely I will grind one out and if I do I will just buy another. My time is more important and more valuable and I want to spend it using the tool not sharpening it.

I fully take Bobs point that a honed edge on a turning tool is pointless as the super sharp edge is gone as soon as the tool is applied to spinning wood. I know that what we need is an edge just good enough for the job in hand and quick and easy repeatability is key. That is what the pro-edge should deliver.

Incidentally, last year I spent about 6 weeks in Japan. I've been a long standing collector of Japanese kitchen knives, and in feeding that obsession I spent a week on a knife making course in an artisan workshop in Japan, near Osaka. ALL of the grinding was done on waterstones and ALL of it was freehand with no rests or jigs. These water wheels are suspended over a massive bath and the wheels are about a metre in diameter. You lean right over them to hold the edge to the stone and a lot of different grind effects can be achieved by a skilled grinder. Final sharpening is done on flat stones of course (Knives are often sold not fully sharpened as the chef or whoever will do their own final edge, secondary bevel and hone).

I also spent a few days working with a top notch UK knife maker who does all of his grinding on a couple of industrial linisher type grinding machines running ceramic belts. One machine is about a metre long in the bed and horizontal, and you grind on it entirely by hand. The other machine is a bit smaller and runs near vertically, and is also used by hand: no jigs or rests. The quality of work is superb - but from someone used to grinding forged flat blanks that he has made (mostly damascus forging). The point of me stating this is that I am well aware that hand work can provide excellent results and it doesn't matter much whether you use a great big wheel or a great big linisher. The issue for me is that turning tools have curvy shapes and it is just quicker for me - as I am not used to sharpening these profiles, to use a jig.

The sorby pro deluxe cost £324 including VAT and delivery, all the jigs and three belts. I have bought a handful of other belts for less than the cost of a cheap gouge and about a sixth of the cost of replacing the basic Tormek T7 wheel. They will last me ages. Once one has purchased all the jigs for the T7 the price is easily £200 - £300 more than the Sorby for something that does basically the same job. The Sorby is cleaner (no water) as well, and these reasons were why I chose it.

 

[Random Orbital Bob]

All of which amounts to....a no brainer. The decision was spot on as we already stated and it will deliver exactly what you expect, also as we already discussed. The whole debate about honing, none use of jigs, doing it by hand etc being the "proper" way was the usual side show that any thread on sharpening seems to have to suffer on this and most other forums. A most bizarre phenomenon I have to say.

It's as if someone has acquired a bit of knowledge and therefore whenever the opportunity to declare it presents itself, despite the relevance of the context....out it pops...over and over.

You'll love it AJ......give us your feedback when you've played with it for a while.

 

[D_W]

I guess nobody on here finishes turnings straight off of the tools?

I don't care too much regarding the rest of the debate, though I'm glad to be rid of my tormek (gave it to a friend) and use a belt grinder freehand to establish basic geometry on turning tools, and then just finish a slightly steeper bevel with a diamond hone.

but anything i turn with a skew, I don't want to sand. And I certainly don't use a skew straight off of a grinder.

 

[Random Orbital Bob]

For me it depends on its intended use. Obviously the skew will give the optimal finish of any of the traditional turning tools and especially a long point cut into end grain where it leaves a burnished finish. But even after a lovely planing cut with no grain tearout I will still run over it with a light pass of 240/320/400 and the finish is unquestionably the better for it. Even masters of the skew like Richard Raffan give their work a quick tickle with 240 grit

But although I haven't made many at all, were the intended use a mallet for the workshop, I cant see the point in sanding it at all when it's only going to get dinged to hell with daily use.

Personally I do use the skew straight off the proedge with either a 120 or 180 grit ceramic belt and it cuts superbly. If I'm about to do a finishing cut though I give it a whisper with a diamond credit card file that lives in my smock pocket.

One thing also worth mentioning is there's a bit of technique to using the proedge. As you take a pass, you'll see if you've got to the edge with a skew in particular because the way the light lands on it changes, you can see the burr form. Once I've detected the burr forming all the way along the edge, I flip it over and gently pass it off and then flip it one more time and even more gently just give it one more pass. In my mind that tapering off of the finger pressure is not only removing the burr but also leaving a finer scratch pattern and is effectively moving up a few grits. It seems to me the edge is finer and I can get gossamer thin shavings with planing cuts.

 

[D_W]

When you say the finish is better, do you mean in terms of the smoothness, or in terms of how the turned piece actually absorbs finish more evenly once it's sanded?

(I'm not much of a turner, honest questions.)

A couple of years ago, I was watching someone turn utility items (knitting needles, etc, but other things, too) at an arts festival and they had spectacular finishes on all of their turned goods, but straight off the skew and nothing more than burnishing (I didn't see them sand anything). The effect far exceeded my turnings (which I generally sand due to lack of skill).

 

[Random Orbital Bob]

smoothness. Cant say I've ever tested it's propensity to absorb finish evenly in that sense.

 

[CHJ]

A couple of years ago, I was watching someone turn utility items (knitting needles, etc, but other things, too) at an arts festival and they had spectacular finishes on all of their turned goods, but straight off the skew and nothing more than burnishing (I didn't see them sand anything). .

One important thing to remember when watching demonstrations at events is the person demonstrating has more than likely selected the stock material to most suit their project and ease their demonstration, they are not going to pick an awkward material or one likely to cause them problems if they can help it. They will in the majority of cases also have had many hours of practice and production under their belt.

Give that same person a project outside their comfort zone, handling rogue grain sections or a piece of interlaced sweet chestnut for instance to turn their long thin spindle from and they may well not be so proficient.

 

[D_W]

The person I was watching was working a variety of things (in terms of materials), but you are exactly correct that they have probably made thousands of things of each type that they had out, and the way they work is semi production, a craftsman's familiarity with every aspect. In this case, they were making things to sell (to finished quality), and not just bringing a tool along to hit a few easy softballs.

An aunt of mine bought a few sets of knitting needles that were made as she stood there, and they were spectacular - laser crisp. First time I've seen non-sanded turned items.

 

[woodpig]

One of the points seemingly missed by those that use a bench grinder is that you can change grits very quickly on the ProEdge. You can sharpen or re-profile a skew with an 80 grit belt then give it a polished edge with a 240 grit (or finer) all with the same jig and setting. If you really want to hone carving tools there is even a rotary hone available for it.

The ProEdge may not do anything that other systems can't but it does do it quickly, easily and more importantly consistently.

It it was half the price it would be a no brainer, the only reason it gives (understandable) pause for thought is that it's not an inexpensive piece of equipment. Once you've bought one though the cost is soon forgotten once you've sharpened a few tools on it.

 

[Jacob]

It is pricy but it's solid, well made and well designed. You can set it from horizontal (if bolted down on a bit of joist) to vertical (freestanding) very easily, plus very quick rest adjustment (to set points) and very quick belt change if you leave the cover off.

 

[lurker]

It is pricy but it's solid, well made and well designed. You can set it from horizontal (if bolted down on a bit of joist) to vertical (freestanding) very easily, plus very quick rest adjustment (to set points) and very quick belt change if you leave the cover off.

:shock:

I'd have never have guessed you would be extolling the virtues of new fangled kit Jacob.
BB willl be along shortly to say what a load of rubbish belt sharpening is (can we have a similie for s£1* stirring :wink: )