Has anyone tackled sharpening 28mm rotary blades? If so, are there jigs out there that would fit the T8?
Thanks much.
The only jig I know of is described on Rich Colvin's treasure trove of a website (https://www.sharpeninghandbook.info/GT-Rotary-Cutter.html).
It requires *a bit* of craftmanship, though...
Tormek has a Round Blade Sharpening Attachment:https://tormek.com/en/products/culinary/culinary-accessories/rbs-140-round-blade-sharpening-attachment (https://tormek.com/en/products/culinary/culinary-accessories/rbs-140-round-blade-sharpening-attachment)
But it fits the T2 sharpener only.
A creative mind and a bit of ingenuity can go a long way, which is amply evident in all that Rich Colvin does.
The manual for the RB-140 is here (https://tormek.com/download/18.402bf0b018388c67fde249/1664457601051/Instruction%20RBS-140.pdf). It states that the range of blade sizes it works with is 80-140mm. But If the mounting shaft size is 12mm, as every other Tormek jig is, it will likely "fit" on the standard USB. From there, it could be just figuring out how to make it work. 28mm is pretty small (1.1"), so that could be your biggest challenge and Rich's jig may be a better approach.
Do a search on the forum for the jig, using the term "RBS-140 Round Blade" and read what discussion there has been about this jig and round blades in general. It does return some irrelevant stuff.
You find a round blade jig at Schleifjunkies shop:
https://schleifjunkies.de/produkt/komplett-set-fuer-rundmesser-bis-50mm-lochdurchmesser-und-300mm-scheiben/ (https://schleifjunkies.de/produkt/komplett-set-fuer-rundmesser-bis-50mm-lochdurchmesser-und-300mm-scheiben/)
The SVD-185,186,186R all come with a shaft specifically for rotary cutters, or am I confusing blades and jigs?
Mike
Quote from: AKMike on October 23, 2025, 10:26:33 PMThe SVD-185,186,186R all come with a shaft specifically for rotary cutters, or am I confusing blades and jigs?
Mike
You are correct. Specifically designed for small carbide inserts but may also be used for round blades, depending.
I've been thinking about this quite a bit since Yukon Jake posted the question 3 days ago.
The rotary knife jig I designed (https://sharpeninghandbook.info/Jigs-RotaryKnife.html) was a modification of the SVD-18x jig, providing a handle to make it easier to rotate the blade for a consistent sharpening process. It works; however I can no longer get the parts to make it as a stand-alone product. It could possibly be re-designed so that it could be 3D printed with a few off-the-shelf parts, and that is what I've been mulling.
In contrast, the Tormek RBS-140 Round Blade Sharpening Attachment (https://tormek.com/en/products/culinary/culinary-accessories/rbs-140-round-blade-sharpening-attachment) uses a different approach (the video on the linked site shows it well). I really like that approach; however it is noted on that page that this attachment only works on the T-2. I don't know if anyone has tried it on the other Tormek grinders (e.g., the T-4 or T-8). It looks like two of the parts are from the SVD-186-R, so I suspect it would work on the T-4 at least.
I think something with the same approach as the RBS-140 could also be designed for 3D printing. But I wonder if it would be safe enough for heavy use.
Thoughts from the community?
Jake,
I re-designed the jig I make to be mostly 3D printed. (https://sharpeninghandbook.info/Jigs-RotaryKnife.html)
It is currently setup for 60mm blades which have a 10mm bore, but I think it could be easily modified for 28 mm blades. What is the bore size for those blades?