Silicon Blackstone equivalent for small Tormek´s (T3, T4)

[aquataur]

(Don´t know which forum this fits. Move if necessary.)

I always was annoyed that Tormek does not sell a 200mm stone equvalent to their Silicon Blackstone.

I found a german guy who sells such a thing:  http://msc-handel.com/#produkte
It is a SiC wheel, grit F320 (=J600). He also has a stone called "Edelkorund weiss" (probably "white fused corundum" or "white fused alumina").
Note: Tormek gauges their grinding wheels according to JIS (I was told by a distributor).
This is a custom job done on special order for him by a well known local maker for abrasives (BSW). The wheel has the same cut-out as is customary for Tormek wheels.
Unfortunately the site is done quite simple and you probably would never find it.

You find him on ebay too.
https://www.ebay-kleinanzeigen.de/s-anzeige/schleifscheibe-siliciumkarbit-f-tormek-t3-t4-200-hartes-mat-/1908645684-84-7639

Use deepl.com to translate it to English if needed.

This stone would need to be treated akin to the SB. Vadim made a nice video about trueing and grading the SB. The dressing stone would not work because it is made from the same material, however the diamond works of course. (I must get some diamond plates as he suggested...)

I sharpened some drills with it and this was a real joy. The SG did not really cope with big HSS drills. BTW I ran into the same problem with the drill jig as everyone, and I landed with the same solution intuitively...

The stone is made very precise, it fits the 12 axle much tighter than the SG that was on the T3, which has play. I have to open and fasten the SG several times to stop it from wobbling side-ways every time I change stones - not on the SiC wheel! The T3´s flanges (if you can speak of such...) are really lousy and don´t guide the stone wheel enough. A fast running wheel with such lousy side support would blow into your face upon turning on the first time.

Have fun
-Helmut

[Ken S]

Welcome to the forum, Helmut.

I have a suggestion which I believe will work well for you. Before Tormek introduced the diamond wheels, like you, I was looking for an inexpensive, fast cutting grinding wheel for my T4. The same wheel fits the T3.

I found the Norton 3X grinding wheels. These are available in 80 and 46 grit. They are available in eight inch (200mm) diameter. Either grit will serve you well. The 46 grit cuts about 20% more quickly. The 80 grit leave a slightly smoother finish. I found that the 3X wheels cut noticeably faster than either the SG or the SB. In fairness to Tormek, the traditional Tormek philosophy was that one grinding wheel should handle the entire sharpening process. Withthe 3X wheels, after the initial rough grinding, we really need to switch to a finer wheel to complete the job.

There are three ways to adapt the 3X wheels to the 12mm Tormek shaft:

The inexpensive "home shop" method I used requires a short length of 5/8" Outside Diameter (OD) plastic water pipe and several 12mm "fender washers".
Lacking a 12mm drill bit, I drilled the plastic pipe piece to 31/64" and held it off center to enlarge the hole slightly. The 3X wheels come with a set of plastic reducing bushings down to 5/8". Slip the piece of plastic pipe inside the reducing bushings.
The 3X wheels are one inch (25mm) thick. The fender washers act as spacers to hold the wheel securely.

The second and much better method is to machine flanges. If you do not have machinist skills and tools, this is an easy and inexpensive job for a local machinist. Show him your T3 and 3X. (If you think you might eventually want both grits, consider having both flanges made at the same time. That is the most cost effective way.) Forum member, Rick Kruger, can advise you much better than I can with machining procedures.

The third method might be to make the flanges with a 3D printer. I have not tried this; however, it seems to have a lot of potential.

I use the 3X wheels wet with my T4. They can be trued and dressed with the TT-50 truing tool. They do the job at a fraction of the cost.

Ken

[aquataur]

In fairness to Tormek, the traditional Tormek philosophy was that one grinding wheel should handle the entire sharpening process.

Thanks Ken,

actually,Tormek chose the stones quite well.

I found a video by Master Nagao: Sharpening with Arato
in which he basically says:
"The Arato [course grit whetstone] is good for re-creating the original shape of the blade and blade bevel. (...)Professionals and experienced users often use a super-fine grit whetstone when sharpening [shiageto]. However, I normally recommend that home cooks use juse a Nakato [medium grit whetstone] because this will provide good edge sharpness and edge durability."

This translates to grit values of

    coarse: < 400 JIS ≡ ca. F240
    medium: 800-2000 JIS ≡ ca. F360 to F600
    fine: > 3000 JIS ≡ F1000

So Tormek is spot on. (Note: Tormek uses JIS grid values a dealer told me...)

I have written a post 10 years ago (my first and only post) where I have found a coarse stone like the one you mention, so I don´t have any needs, but thanks for the tip. Others will profit from it.

BTW I have done some 3d-printed adaptors for my old bench grinder. For these, the wheels must be mounted as precise as possible. I bought grinding wheels from BSW, who are a respectable manufacturer. It seems it is not easy to make an exact adaptor for coarse wheels.
The adaptor is not exposed to dramatic forces, since respectable bench grinders have decent mounting flanges.

That said, the fine SG grit should allow for a much preciser bore than the wheel I have has. The SiC wheel is very exact...
I see no easy method of permanently fixing this. What helps is a layer of thin tape on the axle.

[RichColvin]

Helmut,

The other option is to find someone who has a Tormek for the 250mm grindstone (T-2000, T-7, T-8), and ask them to pass down their grindstone to you when it has no more useful life.

I did some analysis on the useful life of grindstones, and ways to extend that life.  It is documented at https://sharpeninghandbook.info/Grindstones-StoneLife.html.

There is a fellow Tormeker who has a T-3 or T-4.  He takes my grindstones when I can no longer use them, and I give them to him for the cost of postage.  The 250mm grindstones are 50mm wide, and the 200mm grindstones are 40mm wide.  Regardless, a 50mm wide grindstone will fit on the T-3 and T-4.  I don't know how long they've lasted for him, possibly he'll respond.

Kind regards,
Rich