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Skew chisel grinding.....was a grind!

Started by Rob, May 24, 2013, 09:27:20 PM

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Rob

Phew.....decided it was time to do my favourite skew chisel today.  Despite using the blackstone as well....a good hour passed and a lot of finger pressure.  I ended up trueing the wheel four times to get it unglazed enough to really move metal.  (I had it vertically mounted for max steel removal too)

No matter how hard I regraded the stone with the grader, it glazed in seconds once you put the skew back on.  It was painstaking to be honest.  In fairness, this was one of Dad's ancient chisels that was completely knackered so it was a total regrind for both bevels.

But....the Tormek.....sharpening...brilliant....shaping....its a real bellyache for anything hard and wide. After this I'm dreading doing the planar blades again!  Despite having invested in the blackstone.  I honestly cant say Im noticing anything different about its cutting ability.  Depressed.
Best.    Rob.

Herman Trivilino

When things like this happen, I think about checking the basics.  I apologize if this is a stupid question, but you are changing out the water in the trough, right?

The only other thing I can think of is a defective grindstone.  Have you sharpened other tools with it?
Origin: Big Bang

Rob

Best.    Rob.

Herman Trivilino

Whenever it gets dirty.   :)

I definitely rinse out the trough after every sharpening session.  The only time I do it during a session is if it's a long one or if I have to true the grindstone.
Origin: Big Bang

Rob

That's pretty much identical to my routine too
Best.    Rob.

Daedalus

Saw this post and I'm having the same issue, if not worse. I purchased a Henry Taylor skew. Previously tried grinding it sharp with a high speed grinder but wasn't confident with my ability to do so, so I purchased the Tormek with woodturning kit. Sharpened my gouges, and chisels, and they seemed ok, the chisels especially. But the skew is actually worse now than when i first purchased it. The metal just doesn't come off. I have trued the wheel several times, changed the water, regraded the wheel umpteen times, but nothing. My fingers got that sore after 4 hours of pressing the skew to the wheel, I finally decided to take drastic measures and although this doesn't sound like the most wise move, I managed to strap the skew to the wheel in such a way that I could leave the tool grinding away for 10 hours, checking on it every half hour. It's not even ground one side down!

I like the tormek and I like the fact that I can safely and accurately sharpen my tools, but this whole skew chisel issue has left me a little concerned that I have spent a great deal of money on a machine that isn't performing as promised. I must add that I am trying to reshape the skew, not sharpen it. But to sharpen it, I must reshape it first. The enclosed DVD states that reshaping can take time, but surely this is ridiculous. I'm sure nobody wants to spend a whole day on one skew chisel.

Has any body else experienced this, or could it be user error. I have contacted the supplier but not really getting a satisfactory response.

Rob

It sounds to me like you're glazing the wheel quickly like I did with mine.  Once that wheel loses its abrasive quality...no amount of pushing or strapping of the tool will improve things.  You have to re-grade the wheel to get it cutting again.
Now the received wisdom on this forum is that you can use the stone grader.  Jeff advocates aggressive use of it....using the corners of the rough side...and frequently.

For my own part, I've done this till I'm blue in the face and have pushed it so hard into the wheel that I've actually stopped the wheel!  It never re-dresses the stone anywhere near as well as using the diamond truing tool.  So now if I'm reshaping a large surface area HSS tool like a skew, I re-diamond true literally every 2 minutes or so to keep it cutting.

That does work (after a fashion) but it's a bellyache and it really burns your stone fast which aren't cheap consumables.

I've now reached the conclusion that for any tool with a lot of surface area that needs reshaping rather than re-sharpening, that the Tormek is not fit for purpose.  I'm rather sad to have to report this because at sharpening it is truly excellent.  But to expect to take even 1 hour on grinding any tool is unacceptable to me.  For turning gouges, fingernail grinds, its brilliant.  I converted 3 factory ground bowl gouges into deep fingernail grinds in about 1.5 hours....I'm happy with that.  I assume its because those edges have relatively small surface area, ergo not much metal being ground, ergo it doesn't glaze the wheel so fast.  Also I think the articulated bowl gouge jig helps the operator to apply pressure on the edge whereas with a skew its hand pressure....no leverage.

The truth is I dread reshaping anything like a skew now and in fact generally avoid it on the Tormek.  One suggestion that's come up here before is to use a separate hand held (after market) diamond wheel dresser and just hold it against the wheel to de-glaze it.  Then you don't need to go to the trouble of re-truing with the tt-50 all the time (which is a drag and inefficient in terms of effort)
Best.    Rob.

Herman Trivilino

Quote from: Daedalus on June 09, 2013, 11:04:42 PM
I like the tormek and I like the fact that I can safely and accurately sharpen my tools, but this whole skew chisel issue has left me a little concerned that I have spent a great deal of money on a machine that isn't performing as promised. I must add that I am trying to reshape the skew, not sharpen it. But to sharpen it, I must reshape it first.

Have you tried a dry grinder to do the lion's share of the shaping?  Just keep a bucket of water handy and keep dipping the steel in the water to keep it from overheating.

It sounds to me like you've got a chisel made of tungsten carbide steel, or something like that.  You may need a diamond wheel to shape or sharpen it.  Is there a local sharpening service you can contact?
Origin: Big Bang

Herman Trivilino

Quote from: Rob on June 10, 2013, 01:21:18 AM
One suggestion that's come up here before is to use a separate hand held (after market) diamond wheel dresser and just hold it against the wheel to de-glaze it.  Then you don't need to go to the trouble of re-truing with the tt-50 all the time (which is a drag and inefficient in terms of effort)

I'd like to hear from someone who has tried this.  I haven't had a glazed-over grindstone to try it on!  Mine seems to need truing long before it ever gets glazed over.  After truing the diamond wheel dresser does a nice job of smoothing the surface so that you can go right to work on tools needing a fine edge.

Jeff recommends finding a chisel that needs squaring, or some similar task, to smooth out a freshly-trued grindstone, but I find I can get around that with the diamond wheel dresser.
Origin: Big Bang

Daedalus

Further to my last post...

The skew I'm having problems with is a Henry Taylor HS21 3/4 inch high speed steel chisel.

I'm disappointed that the Tormek is pants at shaping but I am pleased with the sharpening of the tools that I managed to sharpen. With reference to dry grinding, I'm going to take my skew to axminster who will shape it on a dry grinder using the tormek kit for dry grinders. This is the only way. It's disappointing that having spent all that money on a tool to sharpen I might have to purchase a tool to shape. The reason I purchased the tormek was because I don't like using the fast grinders, hence why I'm taking it to axminster. I think in future, as I buy my chisels from Axminster, I'll get them to shape it in the shop using the tormek jig on the dry grinder and then I only have to sharpen it when required. Frustrating that I have to do it this way as it will cost me a few quid each time I need the dry grind, but I'd rather pay a few quid to get it sorted rather than spend a whole weekend trying to sharpen one tool!

It'll be interesting to know whether anyone else has the Henry Taylor skews and wether or not they have been shaped and sharpened purely on the tormek. I'm thinking of asking axminster to try to shape it purely on their tormek to see if they get the same issue.

Rob

I didn't know Axy did a shaping service.  That's useful information.  So you're saying that Axy have the Tormek jig setup on a dry grinder (it's the BGM 100 or some such??).

I've not seen that in action but I guess it makes sense if you want the speed of dry grinding plus the control of the jigs.  That might be another solution for me as I have the jigs already.  I'll have a gander down at the High Wycombe branch and ask...I'm due a trip for more sanding discs and wax anyway.  Cheers
Best.    Rob.

Daedalus

Not sure if all Axmister shops sharpen tools, but Warrington does. Best to check first. They have a dry grinder with the bgm 100 ( I think ). They shape the tools with that if necessary then tranfer the tool to the Tormek to get it sharp as possible. Having the dry grinder with the bgm 100 would probably solve all my problems but I don't have the room for another grinder or the budget. And I'd probably only be buying it for the skew, which I hate using anyway! :-) So the axminster solution is best for me. But I am gonna ask them to try to shape the skew on the tormek first to see if I'm doing something wrong, or to make sure the chisel isn't hardened in anyway.

Herman Trivilino

#12
The BGM-100 looks like it should be a cheap and easy way to do it yourself.

http://tormek.com/international/en/accessories/other-accessories/bgm-100-bench-grinder-mounting-set/

This video is a nice illustration of the set up.

https://www.youtube.com/watch?v=j46grxNMsmo

It looks like he's got an aluminum oxide grinding wheel.  They're supposed to run a lot cooler.

http://www.rockler.com/product.cfm?page=10088&utm_source=google&utm_medium=cpc&utm_term=&utm_content=pla&utm_campaign=PLA&gclid=CKr22_yU27cCFVNp7AodOC8ATA
Origin: Big Bang

Rob

I think that's the way to go.  If Tormek are paying Alan Holtham to demo the bgm-100 then the "games up" with respect to shaping...they're basically admitting its not fit for purpose. So the question now is which dry grinder do I buy?  Whats the pro's and cons's with respect to dry grinders.  I have an ancient one but that wont do.

What sort of wheel should it have, what diameter etc etc.  Anyone?
Best.    Rob.

Ken S

Rob, my dry grinder is a forty year old Sears with six inch wheels.  It has served me well enough.  I have a Norton 3X 46 grit wheel on one side.  The other side, which has not been used since I purchased a Tormek, has a Norton80 grit white wheel.  I have thought about swapping it out for a rust removing plastic wheel.

If I was buying a dry grinder today, I would probably buy an eight inch slow speed Baldor.  I would swap out one of the wheels with the Norton 3X 46 grit wheel.  Probably a finer, maybe 80 grit for the second side, although not a priority.

A new Baldor would probably cost as much as a Tormek.  I would buy it for the same reason; Baldor makes a quality product.  I don't know what the equivalent would be in the UK.  Overkill? Probably.

Do I actually plan to purchase a new dry grinder? No.  My old one suffices for my needs.  Especially since I also have an old belt grinder.  Between a dry grinder and a belt grinder, I would lean toward the belt grinder first.  Mine cuts very fast.  It would require some thought to modify it with a BGM-100.  I would look into the Multitool belt grinder Sharptools has for sale.  It looks like a solid product, and might work with your old dry grinder, at least temporarily.

Is Tormek throwing in the towel with shaping by selling the BGM-100? Or are they trying to extend their market to those who already have a dry grinder and would like to use the Tormek jigs?  I could see many of this market starting with the BGM-100 and jigs and eventually buying a T7.  Not a bad marketing strategy.

I have not tried reshaping with my Tormek.  I have watched Jeff reshape a gouge on the turning DVD.  While not super quick, it did not seem that arduous a task.  Is the problem the tool or the technique?

Ken