Grinding wheels....

[sbachner]

Why are the SB-250 and SJ-250 not mentioned on the Tormek website?

Also, using the TT-50 to "rough up" the standard wheel helps reduce grinding time.  Would use of the SB-250 alone reduce grinding time further?

Finally, what are the approximate grits of the SB-250 and SJ-250?

Cheers,
SteveB.

[Jeff Farris]

Patience, Steve. 

We're working on the web pages for the SB-250 and SJ-250. 

The SB-250 provides faster cutting of HSS steel and exotic alloys, however the original SG-250 provides faster cutting on carbon steel tools.

The SB-250 is 220 grit and can be graded to 1000 with the stone grader.

The SJ-250 is 4000 grit.

[sbachner]

On a kinda related note....

I sharpened a few draw knives using the universal support in the horizontal position.  At the same time, I kept the TT-50 setup in the vertical position (I have 2 universal supports).  I really liked this arrangement because I could quickly "rough up" the wheel with the TT-50.

For chisels though, I use the universal support in the vertical position.  Unfortunately, the TT-50 doesn't quite reach the wheel when it's used in the horizontal position.  Just wondering if you thought of ever using the TT-50 in the horizontal position?

This would only apply for grinding.  I never tried grinding a chisel/plane iron in the horizontal position; maybe that would do for just the grinding step?

Thanks Jeff!

Cheers,
SteveB.

p.s. sorry for "sounding" impatient...I was really just curious since the wheels are available at The Best Things and this issue is always at the top of the list for those who like to bash the Tormek

[Jeff Farris]

Steve,

Using the TT-50 to refresh the surface of the stone seems like using a shot gun to kill a fly, to me.  What's wrong with the stone grader?  Use the corner if you want to rough it up fast.

[sbachner]

I seem to put the wheel out of shape quickly with the stone grader when I use the edge or increase pressure.

[Jeff Farris]

Could be, but my guess is that it is the drawknives, not the stone grader that is getting the stone out of shape.

[gfsimpson]

RE new wheels ; are the marketing people too slow for the production crowd ? I am VERY interested in the new technology...everyone is going PM and find the present stone a let down.Cann't we get some tech specs..even far away in SA I can buy your product!
George Simpson

[Jeff Farris]

I'm not sure what "PM" means, and I don't know of many people disappointed with the standard SG-250.

The SB-250 Blackstone is a 220 grit silicon carbide grindstone designed to work with the stone grading system, giving you the same two grit capacity as the SG-250.  The Blackstone's abrasive characteristics deliver faster cutting on high speed steel and exotic alloys.  It is an excellent alternative for those customers who frequently reshape turning tools and/or sharpen high speed steel jointer and planer blades.  However, on normal tool steel, the SG-250 remains the better choice.

The SJ-250 Japanese Waterstone is a 4000 grit synthetic stone that delivers an extremely fine finish.  However, the tool must be perfectly shaped prior to working on the SJ-250.  It is extremely fine cutting, but very, very slow at removing material. It is a good choice for carving tools and well maintained high grade knives and scissors.

[n7blw]

'PM' is powdered metal. Many of the turning gouge and skew makers are starting to use the technology, whether or not a cryo treatment is used, to get more uniform distribution of carbon and other alloys in the metal. Doug Thompson ( www.thompsonlathetools.com ) makes highly regarded turning tools from PM materials. I have easily sharpened one of his 5/8 inch bowl gouges on my original Tormek SG-250 stone. It didn't seem any more difficult than sharpening a carbon steel tool.

[maxwell11]

Hey Jeff could I mount a new SJ-250 on the left hand side, where the leather strop wheel now resides on my T7?
Than I would have 220/1000, and 4000 grits all available. I don't find myself using the strop wheel.

Thanks, Max

[Jeff Farris]

Neither a stone nor a water trough can be mounted on the honing wheel side of the machine.

You're missing a wonderful tool if you're not using the honing wheel.  It is a significant part of the the Tormek edge.

[boehme]

About half of my bowl and spindle gouges are powdered metal and about three of them also have been cryo treated.  I use the standard stone and see no difference in the time that it takes to resharpen any of them compared to the standard M2 HSS.  Usually, two or three quick passes across the face of the tool  and a couple wipes on the leather honing wheel which takes less than a minute total time is all that it takes to get back to the lathe and continue turning.  If I were sharpening tools that had very large area bevel surfaces in contact with the stone, then I might consider the silicon carbide stone, but the only time that it would be necessary on turning tools would be for shaping.  On the rare occasions that I shape a tool, I go to my dry grinder and let the dust fly.

[n7blw]

I concur with what Boehme had to say. I find reshaping on the Tormek to be very time consuming, so have gone to the dry grinder and the Wolverine jig for shaping. Sharpening of PM with cryo treatment (a Doug Thompson 5/8 gouge) took no longer than any of my HSS tools.
_______________
Jim