(https://forum.tormek.com/index.php?action=dlattach;topic=3792.0;attach=2870)
It works!
This week... try something different! ;D
(Post it here!)
Great idea, CB. Thanks for sharing. :)
Jan
Clever.
Ken
CB, great idea, both for the clamp and for the thread!
I may have to dust off my old Lansky just to say I've tried it... :)
I have tested the Lansky knife clamp on Tormek and can confirm that it works and really has a self-centering capability mentioned by CB. :)
The Lansky knife clamp is of subtle construction, the jaws are only 25 mm wide and so the grip is not very firm. It is made of extruded aluminum. The quality of manufacturing is not comparable with zinc Tormek knife jig.
My Lansky clamp has a notched design. The notches are good for holding small and narrow blades, e.g. pocket knife blades.
The Lansky clamp holds good blades with parallel sides also, provided they are wide enough.
The Lansky clamp does not provide good grip for strongly tapering blades, esp. those which are not sufficiently wide. The grip is reduced by the notches, because here the jaws are not in contact with the blade.
Jan
Interesting observations, Jan.
I think of the Tormek jigs as parabolas. At the base of the parabola are tools which can not or should not be sharpened with the Tormek using that jig. As we move up the slope, we encounter tools which can be sharpened with that jig, although not ideally. Ascending the slope further, we encounter tools which are sharpened very well with the jig. The same conditions apply as we pass the apex and descend. For my work, essentially basic kitchen knives and pocket knives, the Tormek knife jigs work nicely. In fact, I could work with only the standard Tormek knife jig.
If I was doing more challenging knife sharpening, I would look into more specialized jigs. Wootz has a set of Tormek knife jigs modified with a milling machine to accomodate a wider range of thicknesses while maintaining good centering. If I needed some of the features of the Lansky jig, but required a more robust jig like the Tormek, I would work with a machinist and have one custom made. The Tormek is designed to work very well with the upper regions of the parabola. Someone who works on the fringes will need to improvise. My first improvation choices would be a Herman style small platform and/or milling the jig slots like Wootz has done. If I needed to go beyond that, I would look into custom machining.
I consider a small platform essential. I do not know why Tormek does not make one. Herman's design using the scissors jig platform is well designed and modestly priced. I really like the idea of using the knife jig assembly for the T2, although the hundred dollar price for just the parts seems excessive.
I think the Tormek is a very versatile machine, which can be even more versatile with intelligent individual modifications.
Ken
Yes, Ken, you are correct! :)
The Lansky knife clamp can easily be redesigned for the use with Tormek. The simplicity with which the self-centering capability is achieved is amazing.
Jan
Does the Lansky clamp give approximately the same total lenght from the USB to the stone as the Tormek clamp?
No, the distance for the Lansky knife clamp is much smaller, only circa 100 mm. You have to lower/bring near the USB adequately. ;)
Jan
Before tormek my main sharpening system was lansky, because I mainly sharpened victorinox Swiss knives with diamond stones, and when time is not a problem, lansky is an excellent option, it has a good cost - benefit, it is a good option for those little blades of folding knives, but now with tormek I think it could solve the self-centering problem, and grab small razor blades, with the improvement of speed. I like the idea
It is good to try new alternatives :)
CB,
How is the Lansky for pivoting?
(https://forum.tormek.com/index.php?action=dlattach;topic=3792.0;attach=2905)
This thread has re-invigorated my interest in working on a self-centering jig for the Tormek. The Lansky is right down the line I was thinking of for the jaw portion. It is just how to combine that with the round shaft of the Tormek jigs. I have a couple ideas that need to be tried. I've ordered two of the Lansky jigs as a leg-up on the jaws. I envision making jaws that are wider once the adaptation to the round shaft is worked out. (please contain yourself, CB ;D )
Rick
Quote from: RickKrung on November 17, 2018, 05:39:01 PM
CB,
How is the Lansky for pivoting?
This thread has re-invigorated my interest in working on a self-centering jig for the Tormek. The Lansky is right down the line I was thinking of for the jaw portion. It is just how to combine that with the round shaft of the Tormek jigs. I have a couple ideas that need to be tried. I've ordered two of the Lansky jigs as a leg-up on the jaws. I envision making jaws that are wider once the adaptation to the round shaft is worked out. (please contain yourself, CB ;D )
Rick
Actually worked better than I thought... might make a good platform for you to experiment with. (And yes, I'm containing myself)... :o
Quote from: cbwx34 on November 23, 2018, 06:13:06 PM
Actually worked better than I thought... might make a good platform for you to experiment with. (And yes, I'm containing myself)... :o
I am still waiting for them to be delivered. One with the rubber inserts at the jaw and one regular one. Former is due for delivery today. I figure to lop off the wings and shorten the jaws so there is room to join them on a shaft. We'll see.
Rick
Quote from: RickKrung on November 23, 2018, 06:22:41 PM
Quote from: cbwx34 on November 23, 2018, 06:13:06 PM
Actually worked better than I thought... might make a good platform for you to experiment with. (And yes, I'm containing myself)... :o
I am still waiting for them to be delivered. One with the rubber inserts at the jaw and one regular one. Former is due for delivery today. I figure to lop off the wings and shorten the jaws so there is room to join them on a shaft. We'll see.
Rick
They both arrived today. But I am grossly disappointed.
First off, I'm not at all impressed with the finish. These appear to be cutoff from extrusions that have been sand blasted to hide machining marks and create a uniform surface appearance. My view of them is that they have been over-blasted, creating an overly rough surface.
The rubber jawed one doesn't hold a blade firmly. The blade wiggles even with the knobs tightened as much as I can with my fingers. I didn't want to use pliers as I think that shouldn't be necessary and I think I'll be returning these, so didn't want to damage them. I realize these jigs are designed to hold a blade stationary while an abrasive is gently slid over the bevels, so perhaps these jaws hold fine for that, but I find them unsuitable for use with the Tormek.
The notched jaw (standard?) one also doesn't hold a blade firmly either. One jaw is flat, but the other jaw is crowned (higher in the middle) and the blade wiggles even worse than the rubber jawed one. I think the notch is useless and only compromises the rest of the jig. This one uses a phillips/flat screw head requiring a screwdriver to tighten for adjusting the jaw opening width, which I find annoying. The rubber jawed one uses a red topped knob, but the jig surface is recessed to compensate for the knob's height.
On both, there is a very slight recess where the locking screw presses to tighten the blade, but it is too shallow and the jaws "walk" apart when the knob is tightened on the notched jaw jig. The other one doesn't, but I think that is solely due to the rubber inserts as opposed to the screw tip staying in the recess on its own.
My assessment is that these jigs do not provide a suitable platform for experimenting with developing a self-centering jig. I'll either fabricate something from aluminum stock that more closely resembles the Tormek jig or take one of my unmodified jaw SVM-45 (knife jig) jigs and cut off the shaft and make other mods I think are necessary for a self-centering jig.
In fairness, these may work fine for use in the Lansky system. I just think they are not a good match for the Tormek.
Rick
Quote from: RickKrung on November 24, 2018, 12:10:33 AM
They both arrived today. But I am grossly disappointed.
First off, I'm not at all impressed with the finish. These appear to be cutoff from extrusions that have been sand blasted to hide machining marks and create a uniform surface appearance. My view of them is that they have been over-blasted, creating an overly rough surface.
The rubber jawed one doesn't hold a blade firmly. The blade wiggles even with the knobs tightened as much as I can with my fingers. I didn't want to use pliers as I think that shouldn't be necessary and I think I'll be returning these, so didn't want to damage them. I realize these jigs are designed to hold a blade stationary while an abrasive is gently slid over the bevels, so perhaps these jaws hold fine for that, but I find them unsuitable for use with the Tormek.
The notched jaw (standard?) one also doesn't hold a blade firmly either. One jaw is flat, but the other jaw is crowned (higher in the middle) and the blade wiggles even worse than the rubber jawed one. I think the notch is useless and only compromises the rest of the jig. This one uses a phillips/flat screw head requiring a screwdriver to tighten for adjusting the jaw opening width, which I find annoying. The rubber jawed one uses a red topped knob, but the jig surface is recessed to compensate for the knob's height.
On both, there is a very slight recess where the locking screw presses to tighten the blade, but it is too shallow and the jaws "walk" apart when the knob is tightened on the notched jaw jig. The other one doesn't, but I think that is solely due to the rubber inserts as opposed to the screw tip staying in the recess on its own.
My assessment is that these jigs do not provide a suitable platform for experimenting with developing a self-centering jig. I'll either fabricate something from aluminum stock that more closely resembles the Tormek jig or take one of my unmodified jaw SVM-45 (knife jig) jigs and cut off the shaft and make other mods I think are necessary for a self-centering jig.
In fairness, these may work fine for use in the Lansky system. I just think they are not a good match for the Tormek.
Rick
Well that's too bad. Your post did remind me of a thread on Bladeforums a while back, where someone who had numerous Lanskys over the years said the quality had declined. (Mine is well over a decade old).
Good thing I contained my excitement! :o
Rick, I will be able to report soon on the Hewn & Hone self-centering jig (designed for Tormek and similar machines). It has obvious blade size limitations because it was designed specifically for scandi grinds on thin carving knives, but it might provide you with some ideas or parameters for your own design.
Gord
Quote from: GKC on November 24, 2018, 08:59:27 AM
Rick, I will be able to report soon on the Hewn & Hone self-centering jig (designed for Tormek and similar machines). It has obvious blade size limitations because it was designed specifically for scandi grinds on thin carving knives, but it might provide you with some ideas or parameters for your own design.
Gord
Gord,
Just seeing the picture is a big help. What would help further are some dimensions. You could PM them so as to not clutter the forum.
I've shifted my design efforts back to modifying an existing knife jig (SVM-45), which may take significant modification, in which case it may be better for me to use the design principles of interest from it and start from scratch.
One feature I may go with is the use of Heli-Coil type stainless steel threaded inserts. I found some locally that are M6x1 so I can use the Tormek screws, which I really like. These would make starting from scratch more feasible.
Thanks,
Rick
I am the odd man when it comes to knife jigs. My knives, both kitchen and pocket knives, generally have very mild curves. I have thought about modifying the jig to eliminate the radius, thus relying on lifting the blade for the tip.I also use several jigs to minimize or eliminate the need to adjust jig length. Therefore, I would be happy eith a finer thread.
I don't expect Tormek to redesign the knife jigs just for me, although if I was a weekend warrior, I would have some custom machining work done.
Ken
Quote from: Ken S on November 24, 2018, 07:11:58 PM
...snip... I have thought about modifying the jig to eliminate the radius, thus relying on lifting the blade for the tip.
Ken, I am not following this. What radius would you eliminate and why can you not already rely solely on lifting for the very mild curves of your knives?
Quote from: Ken S on November 24, 2018, 07:11:58 PM
I also use several jigs to minimize or eliminate the need to adjust jig length. Therefore, I would be happy eith a finer thread. ...snip...
Not following this either. Finer thread of what? If you have multiple jigs, each set at different projections (I'm assuming this) that you hardly ever change, why would the pitch of the thread (of the stop) matter?
Rick
Rick,
I would eliminate the radius on the adjustable stop. Actually, this would probably mean having two adjustable stops, one specifically designed for fairly straight blades and one for more curved blades. This bothered me more years ago; I may have outgrown the need for it.
I guess the shaft thread does not matter. As I rarely adjust more than a small amount (and much of the time require no adjustment at all) adjustment speed is of no importance to me. I would prefer fine adjustment. I realize that is a minority opinion.
The jig is essentially well designed, although I believe it can be improved.
Ken
Rick,
The SVS-50 Multi Jig is designed to include radiused skews. It has a flat bearing surface against the support bar.
The scissors jig has no radius surface, even though scissors often have some radius.
Why do we need a radius on the adjustable stop of the knife jig for knives with little curve? (I think the Tormek plan is for a "universal", one size fits all adjustable stop. I propose that a dedicated flat adjustable stop for straighter blades would work better.)
Ken
OK Ken, I wasn't going to post about this idea, but...
A few of your points about eliminating the rounded edge on the adjustable stop, and having one stop for straight blades and a separate one for curved, prompt me to post these pictures of a "concept jig" I made to go on the knife jigs, for reasons similar to those you mention.
It had occurred to me that you could have both the "keep it straight" support of a flat surface bearing on the USB (the evident purpose of the wide collar on the current Tormek stop), and the ability to pivot with complete freedom (and without changing the radius/projection) when you came to the curve. All in one jig.
It is shaped like the prop of an airplane, so I called it a "prop collar". The "blades" are 1/8" aluminium mounted (JB Weld) on a stop collar (tightens with a grub screw).
Going in each direction, the flat blade of the prop holds you straight, then you can pivot when you reach the curved section of the blade. (the pivot point, if you want to pivot, is exactly in the centre of the collar.) Then you flip over and do the other side, as you do normally. It even gives you decent support if you are lifting, or pivoting and lifting.
Though I only made this prototype to test the concept, I have tried it and it really works, you just have to get the feel for the direction you are going, and develop some muscle memory. Keep it flat against the USB for full control as you are sharpening the straight section, then pivot as much as you want once you come to the curve. Flip and repeat.
Gord
Gord,
This looks intriguing. I will examine it further in the morning when my brain is more awake,
Ken
Quote from: GKC on November 25, 2018, 06:55:12 AM
...
It had occurred to me that you could have both the "keep it straight" support of a flat surface bearing on the USB (the evident purpose of the wide collar on the current Tormek stop), and the ability to pivot with complete freedom (and without changing the radius/projection) when you came to the curve. All in one jig.
It is shaped like the prop of an airplane, so I called it a "prop collar". The "blades" are 1/8" aluminium mounted (JB Weld) on a stop collar (tightens with a grub screw).
Going in each direction, the flat blade of the prop holds you straight, then you can pivot when you reach the curved section of the blade. (the pivot point, if you want to pivot, is exactly in the centre of the collar.) Then you flip over and do the other side, as you do normally. It even gives you decent support if you are lifting, or pivoting and lifting.
Though I only made this prototype to test the concept, I have tried it and it really works, you just have to get the feel for the direction you are going, and develop some muscle memory. Keep it flat against the USB for full control as you are sharpening the straight section, then pivot as much as you want once you come to the curve. Flip and repeat.
Gord
Although I don't think keeping the straight part straight is that big an issue, (for most knives anyway)... I admire the creativity of your solution. Pretty cool! (and an appropriate post for this thread). ;) I do understand the design... the desire to have both a pivot and flat in one jig is a good idea. 👍👍
Quote from: Ken S on November 24, 2018, 10:43:54 PM
...
The SVS-50 Multi Jig is designed to include radiused skews. It has a flat bearing surface against the support bar.
The scissors jig has no radius surface, even though scissors often have some radius.
Why do we need a radius on the adjustable stop of the knife jig for knives with little curve? (I think the Tormek plan is for a "universal", one size fits all adjustable stop. I propose that a dedicated flat adjustable stop for straighter blades would work better.)
Ken
I"ve never used the SVS-50... so I'll just quote from the book. You can put a curved edge on a skew... you
pivot the jig with the tool on the universal support...
(https://forum.tormek.com/index.php?action=dlattach;topic=3792.0;attach=2937)
... so it is not always used "flat".
The scissors jig is essentially a platform jig, with the clamped scissors riding on a platform, so it also is not "flat"... and can follow a curve? ??? (BTW, if a person doesn't believe in "pivot" vs. "lift"... doesn't the platform jig rely entirely on the former?)
Quote from: Ken S on November 24, 2018, 08:26:17 PM
...
I would eliminate the radius on the adjustable stop. Actually, this would probably mean having two adjustable stops, one specifically designed for fairly straight blades and one for more curved blades. This bothered me more years ago; I may have outgrown the need for it.
...
I'm curious... how much "flat" do you need in a jig to keep the knife jig flat against the USB? The standard jig seems to have plenty of flat surface... I don't understand the desire to eliminate the radius... just don't use it? Realllly not getting this... ???
My first exposure to sharpening knives with the Tormek was from watching Jeff Farris' video. Jeff explained that the way to sharpen the tip of the knife was to lift the handle of the knife, not rotate the knife. I found the radius on the adjustable stop a constraint for the standad kitchen knives I sharpen. While the radius may be useful for more curved shapes, I would have preferred a flatter surface for my knives.
In the long run, I believe an ideal knife jig would have more than one easily interchangeable adjustable stopd.
Ken
Regarding self centering clamp- I've seen something like this used in a machinist's shop before. It's a relatively simple mechanism- two opposite thread pitches guide a ram along two exterior rails. If we could figure out a way to miniaturize this, and perhaps recess and angle the jaws so they don't interfere, I think we would be set. The problem would be ensuring the mechanism doesn't get in the way of the stone.
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.spreitzer.de%2Fen%2Fclamping-technology%2Fcentre-clamping-vises%2F&psig=AOvVaw3Rbg-rf8IDQ8XefezsU019&ust=1611008691047000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCIjUgKSBpO4CFQAAAAAdAAAAABAD
Extrapolating from this setup, something along these lines would be might be simpler. The black bit remains exactly in the middle at all times. If we attach the post to the rear of the equivalent black bit, and cut reliefs in the jaws, I think this could very well work. A friend of mine is a machinist, but I'm afraid I have just about zero budget right now (t8 and KG purchases.) Anyway that's my very amateur two bits.