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the learning curve.

Started by Mal55, October 09, 2013, 06:29:51 AM

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courierdog

Rob, I suspect there are more basic  factors for Tormek choosing only sharpening. Until they decide to move onto Shaping then staying with Sharpening and supporting what they do well is smart. While I would like a Shaping wheel I can continue to look.
I will in the interim obtain a 10 inch bench grinder to minimize any differences between Shaping and Sharpening
Retired Engineer

Jambe

If Jeff will allow a short comment...
I bought a 10 Jet bench grinder and the Multitool. Unfortunately the Multitool came with an inexcusable manufacturing flaw--a "bump" on the flat surface caused by a weld on the underside of it. Some day I will grind it flat even though it will bugger the anodizing. I suppose after using it for some time it would be removed anyhow.

courierdog

Jamie, I have looked at all other wet grinding machines. Non IMHO are in any way equal to or superior to the current Tormek. While it is easy to criticize Tormek for not extending their line, those who do not have to wear the accountability hat can do anything they choose as they risk nothing. While I would like Tormek to develop/find/supply/second source a SHAPING wheel, only those in Tormek who can envision a place in their product line can decide this. To me it would be a reasonable thing to second source a wheel suitable for the express purpose of shaping. A wheel which could take any non work profiled tool piece and quickly bring into a rough working profile would be worth a lot as it would reduce any sharpening process and could also be used to roughly return a misused tool to some semblance of working shape prior to the sharpening process. As the tormek system is a slow speed wet process no high speed or heat related metal fatigue would result from its use if such a shaping wheel could be found. I feel like I am wishing upon a dead star on this issue.
Retired Engineer

Rob

The speed of the Tormek wheel coupled with the reality of centrifugal force (water thrown off the wheel at higher speeds) mean the Tormek system will never be capable of a shaping, regardless of the wheel abrasive technology.  The design is not correct for shaping.
Best.    Rob.

courierdog

Retired Engineer

Stickan

It´s possible to shape a tool on the Tormek, but it takes more time than an drygrinder. The SB-250 Blackstone makes it faster than the SG-250 standard stone.
As Rob wrote, higher speed makes it throw water. Our motor can handle high pressure instead that will remove material faster.

When you are about to shape a tool, you need to use the stonegrader frequently, you want the stone to be at 220 grid.
And if you don´t do that, it takes longer because you are slowly making the stones grid finer and finer.

However, if you are shaping tool very often, the BGM-100 kit will make the process faster but you need to be very careful not to damage the tools with the heat.


Rob

Hi Stickan

Personally I think you have to be very careful indeed in suggesting the Blackstone as a "solution" in this debate. I bought one for circa £100 some time ago and frankly it is not fit for purpose as a shaping technology.  It's superb for sharpening high speed steel on turning tools et al and I do appreciate it CAN be used for shaping.  That's the big caveat here, just because it can doesn't mean it should!

I note that you do also consider getting the jigs to operate with a dry grinder by employing the BGM-100 as a faster approach, which I agree with as I have one also.  I just would (being very honest here) not advise folks to purchase the Blackstone wheel and invest quite a sum if their assumption is that it will solve their shaping problems because, it won't.  If they go the dry grinder route ,I also agree they need to watch the heat like a hawk.
Best.    Rob.

Ken S

Rob,

I'm curious. You are a turner.  I have enough "head knowledge" (as opposed to hands on experience) to know that gouges and other turning tools often do not come from the factory with the desired shape. 

As the alchemists ventured farther from carbon steel, the magic long lasting edges have also become harder to shape.

My question is how many tools would a typical turner need to reshape? The investment in a dry grinder setup would seem steep for one or two tools.  For six or eight, it might seem a wiser investment.

Have you tried giving one of your sons a squirt bottle to hose down the tool while you arre dry grinding?  That's a low tech idea, but it might keep the blades cooler.

Ken

Rob

LOL...good idea Ken......I should get them up chimneys after that :-)  Actually my eldest would love to do that.

Its a good question, one I've struggled with myself.  You see I didn't want to admit to myself at first that the T7 couldn't handle all my needs.  The capital cost to acquire the tooling and jigs is high as we all know and I think I was in denial that it wasn't able to shape or sharpen everything on the planet.  A combination of over zealous marketing and users justifying their own purchases can be very seductive and I think is quite capable of luring people into a false sense of security.

When I became interested in turning I had a number of old tools from my Father and I bought some basics new, all of which were HSS.  Dad's stuff was all carbon steel.

So in my case I had probably 6 of Dad's tools which had all been done by hand and were truly horribly out of true.  Also 2 new deep fluted bowl gouges of different widths, 2 spindle gouges and 2 scrapers.  That was just at the start.  Since I have many more shapes including some of the tools where you only sharpen a tip piece which is fitted to a shaft.

So lets just restrict the conversation to Dads and my early HSS selection, which is:

Dads
3/4" roughing gouge
11/4" skew
1/2" skew
bedan
1/4" parting tool
3/8" spindle gouge

All horrible and all needing shaping.  The skew was miles off 15 degrees and the bevel was like the surface of a cut diamond it had that many facets!  Basically they all needed serious attention.

The new ones (HSS)
1/2 and 3/8" deep fluted bowl gouge all ground to factory 45 degrees with wings in line (horrible)
2 different width spindle gouges 1/4" and cant remember the other
3/4 and 1/2" round nose scrapers.

I started with Dad's big skew.....carbon steel only.  After not only regrading the (silicon blackstone) wheel numerous times....and I mean leaning on it to the point it stopped the shaft.....I started using the diamond truing tool to get it literally as abrasive as possible.  I probably went through about 2-3mm of wheel diameter in that one sharpen.  It was an absolute nightmare.  Took well over half an hour, fingers were sore.  Just awful.  Stretched out in front of me were all the rest of Dad's tools and then at the very least the 4 gouges because of course I wanted fingernail profiles for bowls, sheer scraping and detail gouges for spindle work.  The wing grinding wasn't so bad on the smaller gouges but it was on the bigger ones and of course it really dishes the grind stone.

I stopped half way through and got the BGM. That helped as it sure goes faster but still the over heating is a makor problem and as you know quenching HSS is not recommended due to micro-crystalline fractures in the steel.

I have since invested in belt technology which to be honourable to Tormek will not discuss brands etc here.  That, in my view is the best compromise between heat management and fast steel removal.

For all the tools I have not yet bought, I will doubtless need to shape them and I now have a solution.

Where I am at today is that I find the Tormek still an excellent sharpening system and also a very flexible one where it can do so many different edge tools.  But I position it in my own mind squarely as a sharpening system and nothing more.  Its just too frustrating to expect otherwise.  The BGM moves further in the direction of shaping because I cant fault the Tormek jigs, they're excellent quality.  But the heat management then becomes the bottle neck to fast progress.  Optimum for shaping in my view is a belt system that supports jigs for repeatability.  I've no idea why that approach is cooler than a dry grinder but for some reason it is and so its what I prefer now.

So if you're shaping one or two tools a year you'd be insane to not use your (massive) investment in the Tormek, but once it becomes a fairly regular occurrence (I must shape something at least 3 times a month if not more) then, another approach is more efficient.

The other thing with turners is they often experiment with different grinds even with the same tool so its not just a once only procedure.
Best.    Rob.

courierdog

First, the SB-250 is an excellent stone for the HSS and Crobalt tool steel tool bits such as I use on my metal lathe. It does not cut on Stainless or mild steel as well as the SG-250 which I think I have mentioned before. Each of the current Tormek stones are excellent at their assigned jobs. from hard experience I have found none are good at the shaping function, removal of large amounts of metal in a short amount of time.
ALL Tormek stones are excellent at SHARPENING which is a precise amount of metal removal from a preformed shape.
Where I have a problem is Blank Tool Bits are just that Blank, Square, HSS or Ctobalt tool steel, or in the case of making the HK-50 from any metal stock from scratch.
1. Using a dry bench grinder is more dangerous, physically as it turns faster and potentially can create more physical damage faster, any high speed grinding operation is more hazardous and the operator MUST observe more safety precautions.
2. Using a dry bench grinder or Belt Grinder releases more toxic metals into the environment. Any one who is an asthmatic such as my self are more aware of these things.
3. Using a dry bench grinder generates a) more heat in the work piece, b) more heat in the operators fingers, c) heat generates more fractures in the work piece, the Belt Grinder may provide an answer here.
Are there alternatives to shaping on a high speed dry grinder, at the current time it would appear not.
Asking questions or suggesting a different view is the purpose of these forums.
I have learned a great deal and using the suggestion by Herman, I built (Ground) a stainless steel HK-50 which while it took a very long time to grind the profile, performs an excellent function in my shop.
When I get my Mill up and running I hope to be able to be able to make a suggestion for an alternate to precision grinding of Blank, Metal Lathe Tool Bits. I have made a proof of concept version and now require a means of making a version in metal which provide a long term solution. This one may surprise quite a few people and provide more people with encouragement to sharpen and shape their own blank tool bits using the Tormek as an alternative to minimize the generation of toxic metal dust.
Retired Engineer

courierdog

Continuing on I have found that the touch up using the Tormek, HK-50 Herman Trivilino, and setting the Sharping angle to match the Super Togeru Sharpening Guide, as a reference, http://www.paulsfinest.com/Super-Togeru-Sharpening-Guide.html,
This enables me to compare the flat stone sharpening to the Tormek.
I can sharpen my daughters knives while I visit her and maintain our own knives at home.
Having bought her the same knives for her kitchen it allows me to sharpen and maintain both sets of knives to a similar standard. All be it I use flat stones to sharpen hers and the Tormek to sharpen our home knives.
For those unfamiliar with a knife sharpening guide like this, it is a mechanical aid to assist in maintaining a blade at a consistent sharpening bevel while sharpening on Flat Japanese Water Stones. The HK-50 has been set to mimic the sharpening bevel of the Sharpening Guide.
This process allows me to replicate the sharpening styles of both the Flat Japanese Water Stones and the Tormek.
The Flat Stones requires at least three stone grit grades, 400 grit for rough edge shaping and nick removal, 1000 grit for actual sharpening and 5000 grit for edge polishing.
This compares to the Tormek SG stone for edge shaping and nick removal. and the SJ stone for final sharpening and polishing, this is assuming the Tormek stone grader is used to achieve the required grit suited to the process required.
I am indebted to Herman for the methodology (HK-50 Home Made Sharpening Jig) which has allowed me to maintain two sets of knives using two different Stone types.
I also like to maintain my skill with the manual, flat water stones, and using the HK-50 and the Tormek is quite similar in technique in that the fingers are use to maintain the stone contact at the point of sharpening contact.
Retired Engineer

Herman Trivilino

I am surprised that the HK-50 doesn't scratch the sides of your knives.  I have to glue a piece of felt to the top of mine.
Origin: Big Bang

courierdog

Herman:
All I can say is I have not observed any scratches as of yet.
I do not use the Tormek with the HK-50 for any length of time, now due to the perfection of the HK-50 and the required bevel angle.
Please note that with the current set up there is a very large bubble of water surrounding the upper and lower portion of the HK-50, perhaps the water bubble is minimizing the potential scratching.
With the current set up my fingers rest lightly on the edge blade opposite the sharpening side held against the rotating stone.
Retired Engineer

Herman Trivilino

#73
Quote from: courierdog on July 07, 2014, 03:12:15 PM
With the current set up my fingers rest lightly on the edge blade opposite the sharpening side held against the rotating stone.

Ahhh...  Perhaps that's it.  I've been pressing down firmly on the upper side of the blade.  I'll have to give your technique a try.

You do have the grindstone turning toward the edge?  And towards you, right?

Is there any way you could post a short video of your technique?  Or even a photo.
Origin: Big Bang

courierdog

Herman:
The technique I use is the same as demonstrated by professional Japanese Knife sharpeners using the Japanese Flat Waterstones. http://www.youtube.com/watch?v=SIw5ChGOADE While at first it was difficult to achieve real results as I continued to practice I began to gain a foothold on the process. When I moved to the Tormek again it was a similar learning curve to adapt the basic principals while using the HK-50 to maintain the Angle while I use my fingers as I I learned while using the Flat Waterstones. Keeping the HK-50 gap only sufficient to clear the rotating stone permits a water bubble nth below and above the HK-50. Slowly move the Blade across the rotating stone while maintaining a light pressure on the blade while in contact with the rotating stone. Which is rotating towards the blade As the technique is practiced the "Sound" of the sharpening approaches that of the flat stone as noted in the above video. When the sound approaches that of the flat stones I have observed a noticeable improvement in the actual sharpening / polishing process.
I would appreciate any feed back if you experience any similar / or different results.
Retired Engineer