The one change you should make to the Tormek...

[Ken S]

Puffin,

Your use of linear shaft support is clever. I would guess that your 40mm width would work quite acceptably with the larger 50mm width Tormek grinding wheels.

I think it is regrettable that Tormek has not chosen to manufacture a small platform jig. Tormek already owns the patent for the Torlock. As you have already encountered, preventing a shaft from slipping with a round hole is problematic. The Torlock accomplishes this quite nicely with its wedged locking design. Less torque produces a tighter lock.

The original purpose of the small platform jig was to sharpen very small knives. Herman has demonstrated that its utility extends beyond that. I have long believed that the next step in its evolution will be interchangeable platforms. Such platforms, especially when combined with the new diamond wheels, will make shaping and sharpening metal lathe tool bits practical. I believe the primary limitation for the small platform jig is our level of imagination.

Keep imaginng! You have good thinking. By the way, the next time you are in a good hardware store, look at the assortment of threaded plastic knobs. The Tormek locking knobs use M6 thread, roughly the metric equivalent of the common 1/4 x 20 thread. I have a collection of different shaped locking knobs. The standard Tormek round knobs work in all cases, however, I believe other shapes sometimes work better, especially with arthritic hands. Tormek is an excellent product. I think Tormek plus imagination may be better.

Just my opinion.

Ken

[cbwx34]

Thank you to everyone who contributes to this thread (and forum). It is a wealth of information.

I made my own version of Herman's support for a total of $4.05 shipped (not counting the two m5 bolts and the m6 bolt) with Aliexpress parts, to avoid having to disassemble it every time I wanted to use the scissor jig.

-SK12 linear shaft support: $1.37 shipped
-Aluminium alloy plate 5mmx40mm, length 100mm: $ 2.68 shipped

I use a 40mm wide plate to match my CBN wheels. It may work fine with the 50mm Tormek wheels but I've never tried it.

The existing screw on the linear shaft support is small and weak, so I removed it and drilled/tapped an M6 thread so I could use an M6 bolt. The aluminium plate was tapped to fit two m5 bolts corresponding to the holes on the linear shaft support. If you don't have a tap set, you can find decent HSS ones for ~$5 shipped.  I filed the lip of the aluminium plate and a little bit off of the corner of the linear shaft support (towards the tormek USB) to be able to go down to a sharpening angle of 10 degrees on 250mm wheels, mainly for scandi grinds. I also scored the inside of the 12mm hole with a file to make it more grippy.

The support is rock solid and performs well. Tightening it to the Tormek bar takes a little too much force to be able to use an m6 knob such as those found on the Tormek jigs so it's inferior to Herman's support in that aspect. This could be remedied by sawing two slots on each side of the linear shaft support where it bends to clamp the tormek USB, but I don't mind using a wrench.

To be honest I don't use it much because I'm more comfortable with the regular knife jig, with a modified collar similar to those found in this thread. I mainly lift the handle to compensate for curvature (mimicking the technique Jeff Farris shows in his videos) though I like the single pivot point when I need to do small adjustments. I get good results (for me) even on small curved knives but I understand professional knife sharpeners may have different standards than I do regarding the knife point profile.

The modified collar I use is just a piece of U-shape extruded aluminium bent into a triangle for the pivot, and epoxied to a 12mm drill depth stop. Originally I was going to make something less ugly, using a "SHF12 12mm horizontal linear shaft support" (~$2 shipped on AliExpress) and a piece of T-shape extruded aluminium epoxied to it for the pivot. The prototype I made works well enough and I never bothered. The only improvement I'll make is to eventually stick two folded pieces of PTFE where the USB rubs against it, instead of the clear tape I currently use.

Thanks for posting your version of the modified collar for the knife jig.  Looks good!  Your version of the platform jig looks well made also.  I'll have to look thru the info you provided.  (Someday I'll make one...). 

Thanks again!  I like seeing other versions of these ideas.

[puffin]

Your use of linear shaft support is clever. I would guess that your 40mm width would work quite acceptably with the larger 50mm width Tormek grinding wheels.

I appreciate you weighing in!

I think it is regrettable that Tormek has not chosen to manufacture a small platform jig. Tormek already owns the patent for the Torlock. As you have already encountered, preventing a shaft from slipping with a round hole is problematic. The Torlock accomplishes this quite nicely with its wedged locking design. Less torque produces a tighter lock.

True. It does seem that only Tormek could make the ideal version of the platform since they own that patent.

The original purpose of the small platform jig was to sharpen very small knives. Herman has demonstrated that its utility extends beyond that. I have long believed that the next step in its evolution will be interchangeable platforms. Such platforms, especially when combined with the new diamond wheels, will make shaping and sharpening metal lathe tool bits practical. I believe the primary limitation for the small platform jig is our level of imagination.

I mainly sharpen knives, chisels and scissors so I haven't had much use for a platform yet, but that could change. It could be used with the leather honing wheel for a quicker setup since I'd only need to mark the USB position for common angles, but again I'm more comfortable with the regular knife jig. I can remove burrs freehand just fine, but for actual polishing with the leather wheel I get better results using the jigs (which is why I replaced the knob with a bolt on the knife jig to clear the USB, another tip I got from here).

Keep imaginng! You have good thinking.

That's kind of you to say!

By the way, the next time you are in a good hardware store, look at the assortment of threaded plastic knobs. The Tormek locking knobs use M6 thread, roughly the metric equivalent of the common 1/4 x 20 thread. I have a collection of different shaped locking knobs. The standard Tormek round knobs work in all cases, however, I believe other shapes sometimes work better, especially with arthritic hands. Tormek is an excellent product. I think Tormek plus imagination may be better.

You're right that other knobs could be better-suited to apply more force. I tried the knob from the SVS-38 but a wrench is quicker and more comfortable. The aluminium in the linear shaft support is quite rigid and resists tightening, but if one were to remove a bit of metal from where is bends maybe the M6 Tormek locking knobs would work fine.

Thanks for posting your version of the modified collar for the knife jig.  Looks good!  Your version of the platform jig looks well made also.  I'll have to look thru the info you provided.  (Someday I'll make one...). 

Thanks again!  I like seeing other versions of these ideas.

Glad you like it despite its appearance! As you can see I'm no machinist.

[cbwx34]

...

Thanks for posting your version of the modified collar for the knife jig.  Looks good!  Your version of the platform jig looks well made also.  I'll have to look thru the info you provided.  (Someday I'll make one...). 

Thanks again!  I like seeing other versions of these ideas.

Glad you like it despite its appearance! As you can see I'm no machinist.

Certainly better than I could do... but I see the beauty in its function. 

[Ken S]

I neglected to mention that my motivation for exploring other shapes of locking knobs was to assist older users whose hands are no longer strong. Hopefully, by this stage of life, we have also acquired some knowledge and wisdom about torque.

Muscular young users should stay with the standard knobs.

Ken

[kwakster]

This is my own current working prototype of Herman's knife rest with a piece of Torlock attached to it.
It already works quite well, but i still have 2 possible modifications i want to try out.

[Ken S]

Well done, kwakster.

I really believe we have only scratched the surface of the versatility of the small platform jig when used in skilled hands.

Keep innovating!

Ken

[cbwx34]

This is my own current working prototype of Herman's knife rest with a piece of Torlock attached to it.
It already works quite well, but i still have 2 possible modifications i want to try out.
...

Nice job.  (Of course now I want to know the mods you're considering)...

Well done, kwakster.

I really believe we have only scratched the surface of the versatility of the small platform jig when used in skilled hands.

Keep innovating!

Ken

Hmmmm... (Freudian slip?) 

[puffin]

This is my own current working prototype of Herman's knife rest with a piece of Torlock attached to it.
It already works quite well, but i still have 2 possible modifications i want to try out.

Looks good, with easier locking compared to mine. Seems like it can be made without sacrificing the function of the tool rest/scissors jig by keeping 2/3 of the Torlock on them intact (or just make 3 of them with a single SVD-110). I too am curious about those modifications.

[Ken S]

I made two platform jigs, one each for the 50mm width T7 and 40mm T4 by cutting an SVD-110 on my bandsaw. The aluminum cuts easily. My jig had a second locking screw hole with a plastic cap. The jigs work satisfactoraly, however, using the scissors jig like Herman did makes a platform with a lower center of gravity. In my opinion, Herman's design is superior. I have just the platform and locking screw parts ordered to make another platform. I have no need for a duplicate scissors jigand by just using parts I can leave the platform set up.

Eventually, I plan to explore interchangeable platforms (after completing assembly of my grandson's 3D printer.

Ken

ps I think it is interesting that this "one change" topic already has ninety nine replies!

[cbwx34]

I made two platform jigs, one each for the 50mm width T7 and 40mm T4 by cutting an SVD-110 on my bandsaw. The aluminum cuts easily. My jig had a second locking screw hole with a plastic cap. The jigs work satisfactoraly, however, using the scissors jig like Herman did makes a platform with a lower center of gravity. In my opinion, Herman's design is superior. I have just the platform and locking screw parts ordered to make another platform. I have no need for a duplicate scissors jigand by just using parts I can leave the platform set up.

Eventually, I plan to explore interchangeable platforms (after completing assembly of my grandson's 3D printer.

Ken

ps I think it is interesting that this "one change" topic already has ninety nine replies!

Pictures.... pictures... 

(I did say "one change"... just didn't say which one).    Definitely been a journey! 

[kwakster]

The first mod i have in mind is to connect the underside of the knife rest to the underside of the Torlock part with a piece of aluminium, with the aim to stiffen up the whole construction by making something of a triangular shape.
Currently there is a little bit of flex at the hollowed end, which can make the aluminium touch the stone sometimes when in use.

If Tormek were ever to make such a knife rest i would like to see a stiff one-piece extruded (maybe 7075) aluminium construction with a triangular shape & an integral Torlock, so the end product would have as little flex as possible.

The second mod is currently still in the brainfart stadium due to this question that keeps nagging me:
What would the cross section of a freshly sharpened knife bevel look like if the knife rest didn't have a flat surface like it has now, but instead would be ever so slightly triangular like a very shallow roof on a house ?
In theory i think i know the answer, but i'm not yet convinced about the feasibility of such a mod.

[cbwx34]

The first mod i have in mind is to connect the underside of the knife rest to the underside of the Torlock part with a piece of aluminium, with the aim to stiffen up the whole construction by making something of a triangular shape.
Currently there is a little bit of flex at the hollowed end, which can make the aluminium touch the stone sometimes when in use.

If Tormek were ever to make such a knife rest i would like to see a stiff one-piece extruded (maybe 7075) aluminium construction with a triangular shape & an integral Torlock, so the end product would have as little flex as possible.

The second mod is currently still in the brainfart stadium due to this question that keeps nagging me:
What would the cross section of a freshly sharpened knife bevel look like if the knife rest didn't have a flat surface like it has now, but instead would be ever so slightly triangular like a very shallow roof on a house ?
In theory i think i know the answer, but i'm not yet convinced about the feasibility of such a mod.

Thanks.  (But you have me stumped on the tringular mod). 

[kwakster]

My working prototype with the triangular mod done.
The piece of aluminium connecting the Torlock piece with the underside of the platform practically eliminates the little bit of flex there was at the very end of it.

[Ken S]

Kwakster,

Very nice design. I especially like your inclusion of the triangle support. Positioning the lock screw in the back makes for good clearance, too.

Good work!

Ken