Author Topic: initial grind takes hours?  (Read 2022 times)

Offline lady_shock

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initial grind takes hours?
« on: September 19, 2022, 08:50:21 pm »
I've recently re-ignited my turning hobby and my motley collection of weirdly ground, poorly sharpened turning tools (along with some that aren't so bad). Since those days, I've added both a Tormek T-7 with a pretty new SG-250 wheel and a T-8 with a DF-250 600 grit diamond wheel. Nearly all the tools need to be re-ground properly but I'm finding it's taking literally HOURS to do.

I spent 4 hours yesterday on a 1" oval skew starting on the SG-250 surfaced to 300 grit, freshly dressed. Initially, the bevel formed nicely, but as I continued, the progress got slower and slower until I  eventually gave up and left a 1 mm crescent of the original bevel. I was literally using a dissecting microscope to see if I was making progress- I was, but INCREDIBLY slowly. I resurfaced the stone a few times thinking maybe some fresh sharp peaks would help and maybe it did, a little.

Other sources (reddit, I know, reddit...) suggest that slow speed water cooled grinding isn't necessarily an effective way to get the initial grind?
Am I missing an important technique here? Thank you for your input!

Offline RichColvin

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Re: initial grind takes hours?
« Reply #1 on: September 20, 2022, 01:52:21 am »
There are 3 steps here:
  1. Shaping
  2. Sharpening
  3. Honing

These are outlined, along with media which could be used at at:  https://sharpeninghandbook.info/Info-WoodLatheTools.html.
---------------------------
Rich Colvin
www.SharpeningHandbook.info - a reference guide for sharpening

You are born weak & frail, and you die weak & frail.  What you do between those is up to you.

Offline Ken S

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Re: initial grind takes hours?
« Reply #2 on: September 20, 2022, 03:46:58 am »
Lady Shock,

Unfortunately, if you continue on your present course, you will quickly burn out. Let's keep that from happening. Pick out a couple "not so bad" turning tools. You can go far with a half inch spindle gouge and a parting tool. Do a fairly basic grind with the gouge. The parting tool should be a quick sharpen.

Take your time. Enjoy sharpening these two tools. Then enjoy turning with them. Nothing fancy, just some practice beads and coves. Add nicely sharpened turning tools as needed, preferably from the "not too bad" group.

I base this suggestion on a "compleat" set of bench chisels I purchased years ago. I spent hours flattening some of the backs. Of the twelve chisels, four would have sufficed. (An offshoot of this was enough pain in my hands to convince me to get a Tormek.)

Good luck and keep us posted.

Ken


Offline RickKrung

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Re: initial grind takes hours?
« Reply #3 on: September 20, 2022, 03:18:31 pm »
You have hit the wall.  Many of us have.  Do not despair, there is hope...

I do not do wood turning and so have not had to deal with sharpening turning tools, but I've experienced the same frustration with knives, chisels, plane blades, drill bits and the like where heavy metal removal can take forever on a Tormek, even with the coarsest available Tormek diamond wheel, the DC250.  I have tried several other approaches for the heavy stuff, but have maintained the Tormek as the core finishing process. 

There are several alternatives.  The ones I've tried (in the order in which I tried them) include :
1) Traditional coarse grinding wheel mounted on a Tormek,
2) Slow speed bench grinder with friable grinding wheels,
3) Belt grinder, variable and reversible speed,
4) Coarse CBN wheels, 80 grit on a slow speed bench grinder and 180 grit on a Tormek.

All of these were outfitted with Tormek support bars so that the Tormek jigs could be used in the same manner as on a Tormek.  All of that outfitting took a lot of work, but it was well worth it.  I have posted quite a bit here on the forum on all of these except 4).  They all worked for the shaping process and could be used along with the Tormek for the sharpening process. 

Traditional coarse grinding wheel mounted on a Tormek

Initially, I was gifted two 8" Norton 3X traditional grinding wheels (64 and 80 grit), which have 1" arbor holes.  They required fitting with bushings with a 12mm shaft hole.  I machined these, but others have used the standard plastic bushings that often come with such grinding wheels with the added step of drilling out PVC pipe for the 12mm shaft hole.  I used the 80 grit wheel on my T8 quite successfully, even though it was 8" on a 10" machine.  One great aspect was that it ran in the water bath, preserving the dust free operation.  Wasn't as fast as the other approaches, but I was much happier.  Subsequently, I was gifted a 10" no-name, unknown grit traditional grinding wheel.  I liked it better for its larger size.  This approach wasn't quite as fast as I would have liked, but it was far faster than the SG or SB grinding wheels. It is definitely the cheapest and almost the easiest solution and I could have lived with this as the final solution.

Slow speed bench grinder with friable grinding wheels

I bought a Rikon slow speed grinder (1750 rpm) with the white grit grinding wheels and fitted it with the USB and an FVB for full functionality with the Tormek jigs.  It worked, but even though the white grit wheels do a lot better at reducing heat issues over traditional grinding wheels, I still had difficulty managing the heat, particularly on thin blades (knives).  I also did not care for the grinding debris it produced, plus it took up more shop real estate, a precious commodity. 

Belt grinder, variable and reversible speed
I bought a Viel 1x42 belt grinder and fitted it with the USB and modified it with a variable speed DC motor and further modified that to make it reversible.  It worked very well, but even with the variable speed, could still generate heat and it still generated dust and took up space. 

Coarse CBN wheels, 80 grit on a slow speed bench grinder and 180 grit on a Tormek
I bought an 8", 80 grit CBN wheel for my Rikon slow speed grinder and a 10", 180 grit CBN wheel for my T8.  The larger wheel was not warranted for use in water, but I do use it with the Tormek ACC solution and carefully dry it after use and thus far have not had any problems with using it in water.  This is not recommended and I take the risk on it.  This combination is now my Go-To...  I use the 80 grit on the bench grinder for a lot of grinding operations, not related to sharpening, but very often it is my first step in heavy grinding for sharpening.  It still generates the grinding debris, but I just accept that now.  Transitioning to the T8, I start with the 180 grit CBN wheel in the water bath, followed by the Tormek diamond wheel series, DC, DF and DE, and that followed by the Tormek SJ wheels.  I believe a very coarse CBN wheel that can be run in the water bath (without worry about voiding the warranty) could be a complete solution and is the easiest and fastest solution, but has a definite higher cost than number 1) above. 

Another solution, that I have not tried is the Wolverine bench grinder tool rest, made specifically for your situation, grinding turning tools. 

Several viable alternatives, just a matter of time and money.

Rick
Quality is like buying oats.  If you want nice, clean, fresh oats, you must pay a fair price. However, if you can be satisfied with oats that have already been through the horse, that comes at a lower price.

Offline Ken S

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Re: initial grind takes hours?
« Reply #4 on: September 20, 2022, 05:41:36 pm »
I respect Rick and his expertise. That stated, I would like to interject some alternative thoughts.

Many of us, myself included, like you, have accumulated "a motley collection" of turning tools. If we are being honest, how many of our motley collection do we actually use? Faced with hours of sharpening, I still recommend stripping down to the basics (to start).

Of the different ways Rick suggested, my first choice would be the eight inch Norton 46 grit 3X wheel. It provides water cooled, dust and spark free grinding just like your Tormek wheels. Unlike the other options, where you can easily spend $500 to $1000 USD, a 3X wheel costs around $60. With a "weirdly ground, poorly sharpened" turning tools will only need reshaping once. Resharpening is easily and quickly done with your present wheels.

Adapting a 3X wheel to a Tormek is an easy and inexpensive  home workshop project. If you decide to go that route, post the question and I will reply with the method. An hour more or less should give you time to complete it and have a cup of coffee.

Ken

Offline RickKrung

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Re: initial grind takes hours?
« Reply #5 on: September 20, 2022, 06:46:30 pm »
I respect Rick and his expertise. That stated, I would like to interject some alternative thoughts.

Many of us, myself included, like you, have accumulated "a motley collection" of turning tools. If we are being honest, how many of our motley collection do we actually use? Faced with hours of sharpening, I still recommend stripping down to the basics (to start).

Of the different ways Rick suggested, my first choice would be the eight inch Norton 46 grit 3X wheel. It provides water cooled, dust and spark free grinding just like your Tormek wheels. Unlike the other options, where you can easily spend $500 to $1000 USD, a 3X wheel costs around $60. With a "weirdly ground, poorly sharpened" turning tools will only need reshaping once. Resharpening is easily and quickly done with your present wheels.

Adapting a 3X wheel to a Tormek is an easy and inexpensive  home workshop project. If you decide to go that route, post the question and I will reply with the method. An hour more or less should give you time to complete it and have a cup of coffee.

Ken

I heartily agree with Ken on the 3X wheel as the easiest and least expensive way to tackle this matter. 

Rick
Quality is like buying oats.  If you want nice, clean, fresh oats, you must pay a fair price. However, if you can be satisfied with oats that have already been through the horse, that comes at a lower price.

Offline Ken S

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Re: initial grind takes hours?
« Reply #6 on: September 21, 2022, 04:52:54 am »
Lady Shock,

You have the stars in perfect alignment……The Pacific Northwest (Rick) and the Midwest (me) are in perfect agreement, a happy occurrance.

Ken

Offline lady_shock

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Re: initial grind takes hours?
« Reply #7 on: September 21, 2022, 08:33:35 pm »
Thank you SO much for the incredibly helpful advice!

Mostly, I was concerned that I was using the Tormeks incorrectly, but this appears not to be so.


@KenS:
You are absolutely right about needing only a small collection of turning tools. Confining myself (for now!) to spindle turning, I pretty much use only my spindle roughing gouge, 1" skew, parting tool and 3/8" spindle gouge. The parting tool caused no issue and I'm nearly done with the skew (save for the slim crescent remaining, which appears like it would take hours to eliminate). The other gouges have been sharpened and honed to usability, but really need a proper shaping.

I would very much welcome advice on mounting the Norton 3x 8" wheel onto my T7, thank you! Does the deeper hollow grind of the 8" wheel cause any issues when sharpening on a 10" wheel?

@RickKrung:
so many good options, thanks!!! What would you think of a 10" 180 grit CBN wheel mounted on the T7 without a water bath, thence to the DF 250 600 grit on the T8?

Offline RickKrung

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Re: initial grind takes hours?
« Reply #8 on: September 21, 2022, 08:51:02 pm »
...snip...
@RickKrung:
so many good options, thanks!!! What would you think of a 10" 180 grit CBN wheel mounted on the T7 without a water bath, thence to the DF 250 600 grit on the T8?

The 180 grit CBN dry on the Tormek would probably work.  I would not do it as I don't want to contaminate my Tormek with all the grinding debris.  I have chosen to go through the full routine of DC, DF, DE because I don't like large jumps in grit levels, so I would not do as you inquire about, but that is just me.  I believe there are those who do.

Rick
Quality is like buying oats.  If you want nice, clean, fresh oats, you must pay a fair price. However, if you can be satisfied with oats that have already been through the horse, that comes at a lower price.

Offline cbwx34

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Re: initial grind takes hours?
« Reply #9 on: September 22, 2022, 02:21:02 pm »
...
Does the deeper hollow grind of the 8" wheel cause any issues when sharpening on a 10" wheel?
...

Maybe?  You might take a look at THIS THREAD... forum member Gilles noted he had to make adjustments going from a smaller to larger wheel.  Not really an issue, just something you might need to be aware of, and adjust for.
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