While I am not convinced that I am good enough on the Tormek yet to improve my results by pivoting (rather than just lifting), I am impressed by the enthusiasm of those more experienced members who like to pivot. I have made the "four stop collars" pivoting mechanism and quite like it. I have one of Rick's collar-and-pin mechanisms on order and comments like Wootz's tell me it will be brilliant. But a postal strike in Canada has delayed Rick's jig getting to me, so I made one of my own that seems to do the job very well. You might call it a wedge collar.
The governing factor in this design was simplicity in fabrication: I am no machinist and I wanted something that could be made by anyone with a hack saw and file (and drill press, for the holes). Also, I wanted to design something that someone could make out of plastic, either by shaping it or by using a 3D printer, and so it had to have more reinforcing bulk than Rick's pin collar.
I find this wedge collar very easy to use. The fingers (of the hand you are using to hold the knife jig) can slide up comfortably behind the wedge; you can leave off the disc supplied with the SVM-45 and SVM-140. The pivoting is very fluid, and the range of pivoting is more than sufficient for the knives I have tried it on.
As I said, I wanted this to be easy to make. It is made from a 2" length of a 1" square bar of aluminium, which I drilled and then cut to a triangular shape.
Stainless steel would be better than aluminium: less friction and wear, but I haven't noticed the friction from the aluminum, and machining stainless steel would require tools I don't have. A block of UHMW plastic should work, and might be nicely slippery on the USB. I don't know much about 3D printing, but the wedge seems like a simple project, perhaps with the holes being done after. Of course, wood would be easiest, but there are drawbacks when wood is used around water.
Gord
Absolutely stunningly brilliant, Gord. I love it. I especially love that it can be fabricated by anyone with basic tools and skills. And that it can be made from just about any material. I have a block of UHMW that I can use to make one from and will try it. I think Delrin would work very well also. Thumb screw for locking it frees one from having to keep a hex key handy.
Bravo!
(You can return the PPC for a full refund if you like ;D I had a request for one that I could not fill. 8)
Rick
What a brilliant idea. Well thought out :-)
Hey Gord, that's really slick! Thanks for sharing the idea and instructions.
Just a short info about my economy version of the pin pivot collar.
I used a flat washer, glued on it two tubes with a high strength epoxy glue (cured at 90°C for two hours). This device I fixed on the standard collar with strong double sided sticky tape.
Works great – and can be removed if needed!
Best regards
Drilon
Quote from: Drilon on November 17, 2018, 06:34:25 PM
...snip...
This device I fixed on the standard collar with strong double sided sticky tape.
...snip...
I love innovation. How does it work with the rotation of the standard collar? Do you just set the projection in increments of half-turns and go from there?
Rick
Now that is clever.
Quote from: RickKrung on November 17, 2018, 08:28:13 PM
Quote from: Drilon on November 17, 2018, 06:34:25 PM
...snip...
This device I fixed on the standard collar with strong double sided sticky tape.
...snip...
I love innovation. How does it work with the rotation of the standard collar? Do you just set the projection in increments of half-turns and go from there?
Rick
Yes, the increments are half-turns.
Drilon
...snip...
This device I fixed on the standard collar with strong double sided sticky tape.
...snip...
I love innovation. How does it work with the rotation of the standard collar? Do you just set the projection in increments of half-turns and go from there?
Rick
Rick, after seeing your great tool I was looking for a way that I can test this method. That was my intention to make the cheap copy. If I come to the conclusion that I like it and use it often I most probably will purchase your professional tool as now offered by Knife Grinders, Australia.
Thank you!
Drilon
Drilon,
I like your simplistic approach. Have an idea, and make up a working prototype. Work with it. I would love to visit Tormek in Sweden. Many years ago, I visited the Leitz (Leica camera) factory in Wetzlar, Germany. I was not allowed to tour the factory, however, I was allowed to visit something much more meaningful. The Leitz Museum Director gave me a personal tour of the museum. Every Leica model ever made was on display. He then opened the safe and let me handle the Ur Leica (the Ancestor Leica),the first prototype hand made by the inventor, Oscar Barnack. It is unique, and among Leicaphiles it is certainly the Holy Grail.
The Ur Leica was made from a piece of 75mm brass pipe which Oscar Barnack flattened into what has become a camera shape. I have been told that the Tormek factory has several odd bits of plywood and other prototype material used by Torgny Jansson in developing the Tormek. I think it would be fascinating to learn more about the nuts and bolts development of the Tormek. I do believe that Torgny's spirit of innovation continues, both with the Tormek design team in Sweden and globally through the forum. I am proud to be a member of this group.
Ken
Like Drilon, I like the simple way of putting something on the SVM-45 collar; I tried a flattened section of 1/2" aluminium bar, stuck on with double-sided tape. It works just fine, and one of these in-front-of-the-collar approaches is quick and easy for someone who wants to see whether they like pivoting. One limitation, as Rick mentioned, is that you have to work in 1/2 turn-of-the-collar increments. Another is that when you mount something in front of the SVM-45 collar, you have to move the collar back by its depth, and probably adjust the USB height. You end up with the collar a bit further back on the SVM-45 shaft than you prefer. But it works and it is easy. Here are some pics.
I think we have two issus to settle:
First, and in my opinion the more important, is getting a smooth pivoting action. I think these jigs do this well.
Second, and of lesser importance, is obtaining a specific bevel angle. The projection of the knife blade in the jig is only one of two adjustments for this. Adjusting the Distance of the support bar from the grinding wheel is the second and probably easier method.
I would just set orient the pivot jig vertically and measure the the projection. The macimum deviation is limited to plus or minus a quarter screw thread. I would check with Dutchman's tables. The slight difference could be easily compensated with another kenjig or tweaking the microadjust. (or, dare I say, ignored)
Either way, I don't see the vertical orientation as much of a problem. Good thought, however, and something to be aware of.
Ken
Quote from: GKC on November 19, 2018, 03:55:24 PM
...snip...
One limitation, as Rick mentioned, is that you have to work in 1/2 turn-of-the-collar increments. Another is that when you mount something in front of the SVM-45 collar, you have to move the collar back by its depth, and probably adjust the USB height. You end up with the collar a bit further back on the SVM-45 shaft than you prefer...snip...
If using pivots attached to the front of a standard collar (and using the O-ring on the shaft), I don't see what the collar's position has to do with anything. I am assuming the projection is set based on the front "pivot point" surface. The USB height is then set according to the projection (or visa versa?). Until the collar falls off the O-ring, moving it back has no bearing on anything, as far as I can see it. Similarly, if using the old style collar with the locking screw, it would be - "until the set screw falls off the end of the shaft".
If one is using a Pin Pivot Collar (PPC) or some brilliant alternative such as Gord's "Triangular Pivot Stop" (TPS), as I use it, the standard collar is not used at all. As Wootz uses the PPC, the collar is there but the projection is set as above and the collar is just to preserve the "feel" and muscle memory motions he uses so well.
Quote from: Ken S on November 19, 2018, 04:41:00 PM
...snip...
I would just set orient the pivot jig vertically and measure the the projection. The macimum deviation is limited to plus or minus a quarter screw thread. I would check with Dutchman's tables. The slight difference could be easily compensated with another kenjig or tweaking the microadjust. (or, dare I say, ignored)
Either way, I don't see the vertical orientation as much of a problem. Good thought, however, and something to be aware of.
Ken
In my view, it is effectively only about 1/8 turn from vertical. Past that and the closer to a full 1/4 turn, the pivot point is too horizontal. Within that 1/8 turn range, I think it could definitely be ignored. The lost portion of the rotation, from 1/8 to 3/8 is 1/4 turn, but the threads on the collar are very coarse, so if only 2mm per turn, that up to 0.5mm of "error". I think that would be a personal choice about whether it could be ignored.
Rick
Rick you say (I can't figure out the "quote" function in posting) "Until the collar falls off the O-ring, moving it back has no bearing on anything, as far as I can see it. Similarly, if using the old style collar with the locking screw, it would be - "until the set screw falls off the end of the shaft"."
That was my only point--and it is a minor one--about having to move the collar back: I found that with mounting things in front of the SVM-45 collar, and to keep my 139mm projection, I had to move the collar back enough that I was very close to the O ring, where the collar has more play. It was just a bit further back than I prefer it. You could move up the collar and lower the USB, it all still works well.
Gord
In order to match the jig to the curvature of the knife tip, the length of the jig should be variable, equa; to the radius of the curvature, and in any case longer than it is now. ;)
Quote from: Dutchman on November 20, 2018, 09:52:45 AM
In order to match the jig to the curvature of the knife tip, the length of the jig should be variable, equal to the radius of the curvature, and in any case longer than it is now. ;)
Hmmm. You make an interesting point, Ton. If I understand what you saying, it is that the curvature of some blades describes an arc with a radius that is greater than the projection available from the current SVM jigs, such that accurate pivoting is already compromised. If this is so, then any projection lost by adding pivot points in front of the SVM collar would further compromise that accuracy. If this is a material concern, then we are best with something like the Pin Pivot Collar or the Triangular Pivot Stop, which at least preserve as much projection as possible from the shaft length of the SVM jigs.
Quote from: GKC on November 20, 2018, 10:05:06 AM
Hmmm. You make an interesting point, Ton. If I understand what you saying, it is that the curvature of some blades describes an arc with a radius that is greater than the projection available from the current SVM jigs, such that accurate pivoting is already compromised.
I believe you are correct, except that the radius of the blade is more often less than the projection available. And I think this is why lifting is still required, even when using any type of "pivot" stop. If the radius is greater, I think, moving the pivot point closer to the curvature can sometimes at least partially mitigate this by making the radius of the projection more closely match the radius of the blade arc.
Quote from: GKC on November 20, 2018, 10:05:06 AM
If this is so, then any projection lost by adding pivot points in front of the SVM collar would further compromise that accuracy. If this is a material concern, then we are best with something like the Pin Pivot Collar or the Triangular Pivot Stop, which at least preserve as much projection as possible from the shaft length of the SVM jigs.
I take it differently. I think it isn't a matter of losing projection due to something in front of the standard collar. In fact, I think use of such "addition", one would move the collar back to put the pivot point at the correct projection. Thus, the type of pivot collar is irrelevant as long as the projection is the same.
I think the real upshot of Dutchman's statement is that, with existing collars/pivot stops, pivoting alone is not enough, that some amount of lifting is still required. Where and how much will depend on the curvature of the blade and how the contact point of the bevel on the stone deviates from the "Line of Contact" (LOC), with or without pivoting.
His statement, to me, suggests that if a jig had a stop device that provided variable projection distance, then pivoting alone might be enough. We do not have any such device at this point, that I am aware of.
I've sure someone will correct on this if it is needed.
Rick
Yes, I can see that lifting could compensate when there is insufficient projection, or when the radius of the arc of the blade changes along the length of the curve (most blades I encounter have a varying degree of curvature along the curved part of the blade). In theory, lifting (alone) should work for many blades.
(A few weeks ago I sent a very precise question to Tormek support about Tormek's information on the geometry and trigonometry of pivoting and lifting, and got back a disappointing non-answer along the lines of "do either or both at once, see what feels right". That might be a realistic answer, but I was hoping for some guidance on the theory even if the theory is not easily translated into practice. Some engineer in Tormek will know this stuff cold, but it seems that they just won't divulge it.)
Perhaps Ton will come back online to clarify, but I took his comment (that the length of the jig should be "longer than it is now") to be indicating that the jig sometimes has too little projection, and this seems intuitive to me for blades with only a gentle curve (thus requiring long projection).
It is doubtless true, as you say, that "the type of pivot collar is irrelevant as long as the projection is the same", but mounting things in front of the SVM collars reduces the available projection (before you fall off the O ring) by the thickness of the thing you mount (about 10mm in the add-on I posted in response to Drilon's jig). I think my only point is that one preserves more projection capability (if needed for a longer radius) with the Pin Pivot Collar and the Triangular Pivot Stop.
I have tried to imagine a jig with projection that changes, during the sweep of a sharpening pass, to match the curve of the blade, but the complexity makes my head spin. Ultimately, experience leading to the ability to do "what feels right" might be the only solution.
Gord
I am new to the tormek and having the same problems with the knife holds. The adjustment knob turns while you pivot the knife. I guess for the money we pay for the tormek, why should we have to redesign their holders? A great deal for them, sell us junk and than have us fix it. So far not to impressed with tormek.
I have a different impression: While in some areas I wish Tormek would introduce new design elements, I am very impressed with the quality of Tormek equipment.
The Tormek knife jigs were not designed for pivoting: indeed, the large collar on the SVM-45 and SVM-140 knife jigs are there in order to help the user keep the blade perpendicular to the wheel; that is, to help the user avoid unwanted pivoting. Curves in the blade can usually be accommodated by lifting the handle rather than pivoting, and the Tormek knife jigs allow the freedom to lift while staying square to the wheel.
The pivoting jigs have been developed by more specialized users to allow a different movement, not because the Tormek jigs are deficient for their intended use.
The movement of the collars of the Tormek knife jigs is a result of Tormek's decision to use the friction of an "O" ring instead of the previous locking screw, which held the collar better but (some thought) got in the way. This is not a bad design, just a design with a different priority.
I have never had a problem with my collars moving, but if I did, I would just install a locking screw.
Gord
Quote from: jwv162 on November 23, 2018, 05:05:36 PM
I am new to the tormek and having the same problems with the knife holds. The adjustment knob turns while you pivot the knife. I guess for the money we pay for the tormek, why should we have to redesign their holders? A great deal for them, sell us junk and than have us fix it. So far not to impressed with tormek.
I have to agree with you at one level and disagree on another. First, the "O-ring" collar does turn at times. I did not like this, so I replaced them with locking screws. Second, the Tormek is definitely NOT junk.
I've never heard or read this idea, but perhaps the turning of the O-ring collar is a matter of too much pressure of the collar on the USB. The USB is just a guide. An unpracticed hand needs to keep good pressure of the collar against the USB. I would ask of those who use the unmodified collar, with practice, are you able to apply less pressure because your muscle memory is keeping it in place and thus the lesser pressure does not cause the collar to rotate? If that is not it, what do you do to keep the collar from rotating?
I would add that the very high level of design and ingenuity shown with the machine and jigs is astounding and the quality of the castings and machining is equally astounding. These are anything but junk. I have heard, but have no first hand experience, that some of the knockoff imitations can be junk.
I suggest you work with the machine and jigs for a while before deciding. If you do decide it is junk, I've been wanting a second machine, so would entertain buying that junk off your hands at at commensurate prices.
Rick
Quote from: GKC on November 23, 2018, 05:28:42 PM
I have a different impression: While in some areas I wish Tormek would introduce new design elements, I am very impressed with the quality of Tormek equipment.
The Tormek knife jigs were not designed for pivoting: indeed, the large collar on the SVM-45 and SVM-140 knife jigs are there in order to help the user keep the blade perpendicular to the wheel; that is, to help the user avoid unwanted pivoting. Curves in the blade can usually be accommodated by lifting the handle rather than pivoting, and the Tormek knife jigs allow the freedom to lift while staying square to the wheel.
The pivoting jigs have been developed by more specialized users to allow a different movement, not because the Tormek jigs are deficient for their intended use.
The movement of the collars of the Tormek knife jigs is a result of Tormek's decision to use the friction of an "O" ring instead of the previous locking screw, which held the collar better but (some thought) got in the way. This is not a bad design, just a design with a different priority.
I have never had a problem with my collars moving, but if I did, I would just install a locking screw.
Gord
Actually, the collar rotates when you rotate the jig, not when you pivot it. ;)
Quote from: jwv162 on November 23, 2018, 05:05:36 PM
I am new to the tormek and having the same problems with the knife holds. The adjustment knob turns while you pivot the knife. I guess for the money we pay for the tormek, why should we have to redesign their holders? A great deal for them, sell us junk and than have us fix it. So far not to impressed with tormek.
I wouldn't say "junk"... but definitely a bad redesign from their previous version, IMO.
Just a bit of FYI... most of the "redesign of the holders" is for other reasons... pivoting, self-centering, etc. About the only thing done to avoid this issue, is putting tape on the jig under the collar, or "re-adding" a locking screw.
Quote from: RickKrung on November 23, 2018, 05:54:55 PM
...
I've never heard or read this idea, but perhaps the turning of the O-ring collar is a matter of too much pressure of the collar on the USB. The USB is just a guide. An unpracticed hand needs to keep good pressure of the collar against the USB. I would ask of those who use the unmodified collar, with practice, are you able to apply less pressure because your muscle memory is keeping it in place and thus the lesser pressure does not cause the collar to rotate? If that is not it, what do you do to keep the collar from rotating?
...
I don't think pressure is the issue... I have a pretty light touch and mine would still move. Adding tape under the collar or adding a locking screw solved it for me (I've done both). Ok... pretty much quit using it is really what I've done.... :-\ ;)
Quote from: cbwx34 on November 23, 2018, 06:11:32 PM
I don't think pressure is the issue... I have a pretty light touch and mine would still move. Adding tape under the collar or adding a locking screw solved it for me (I've done both). Ok... pretty much quit using it is really what I've done.... :-\ ;)
I wonder if a fatter O-ring would help, if it would fit in the space. The existing one can be difficult to get the collar over already. O-rings are great for sealing joints, but are not meant for that kind of service (anti-rotation).
Rick
As I noted, I haven't had a problem with my collars moving, could it be that Tormek has increased the O ring size or composition (my purchase was fairly recent)? Or, perhaps as my O rings wear down, the problem will surface. I have quite a good machinery parts supplier near me, and I know they carry thin and fat O rings for the same inside diameter, I will see what happens with a fatter O ring. But I agree that a locking screw is the real answer when this issue surfaces.
Gord
Quote from: GKC on November 11, 2018, 11:39:12 PM
...You might call it a wedge collar.
The governing factor in this design was simplicity in fabrication: I am no machinist and I wanted something that could be made by anyone with a hack saw and file (and drill press, for the holes). Also, I wanted to design something that someone could make out of plastic, either by shaping it or by using a 3D printer, and so it had to have more reinforcing bulk than Rick's pin collar.
I find this wedge collar very easy to use. The fingers (of the hand you are using to hold the knife jig) can slide up comfortably behind the wedge; you can leave off the disc supplied with the SVM-45 and SVM-140. The pivoting is very fluid, and the range of pivoting is more than sufficient for the knives I have tried it on.
As I said, I wanted this to be easy to make. It is made from a 2" length of a 1" square bar of aluminium, which I drilled and then cut to a triangular shape.
Stainless steel would be better than aluminium: less friction and wear, but I haven't noticed the friction from the aluminum, and machining stainless steel would require tools I don't have. A block of UHMW plastic should work, and might be nicely slippery on the USB. I don't know much about 3D printing, but the wedge seems like a simple project, perhaps with the holes being done after. Of course, wood would be easiest, but there are drawbacks when wood is used around water.
Gord
I like it!!
Quote from: Drilon on November 18, 2018, 11:44:23 AM
...
Rick, after seeing your great tool I was looking for a way that I can test this method. That was my intention to make the cheap copy. If I come to the conclusion that I like it and use it often I most probably will purchase your professional tool as now offered by Knife Grinders, Australia.
Thank you!
Drilon
Yours is also a good idea! As long as it holds... it'll work just as good as the "original". ;)
The main thing with all these ideas, is simply to reduce the pivot area of the collar on the USB.
Quote from: Dutchman on November 20, 2018, 09:52:45 AM
In order to match the jig to the curvature of the knife tip, the length of the jig should be variable, equa; to the radius of the curvature, and in any case longer than it is now. ;)
This I will have to think about.... do you mean the distance by adjusting the collar (screwing it in or out more... vertically)? In my mind, it's more of the distance created by how far away you clamp the belly/tip area (more horizontally). Vertical (for me) provides "maneuvering room". :)
Quote from: wanderingwhittler on November 14, 2018, 03:29:28 AM
Hey Gord, that's really slick! Thanks for sharing the idea and instructions.
Are there any additional instructions for Gordon's jig other than comments in his post? Knife grinders stopped selling Ricks design. Are there any similar jigs available that can be ordered?
Quote from: harivney on May 22, 2020, 04:59:20 PM
Are there any additional instructions for Gordon's jig other than comments in his post? Knife grinders stopped selling Ricks design. Are there any similar jigs available that can be ordered?
Go join the Tormek Group (https://www.facebook.com/groups/272080627062383) on Facebook... and have a look around. ;)
Quote from: harivney on May 22, 2020, 04:59:20 PM
Quote from: wanderingwhittler on November 14, 2018, 03:29:28 AM
Hey Gord, that's really slick! Thanks for sharing the idea and instructions.
Are there any additional instructions for Gordon's jig other than comments in his post? Knife grinders stopped selling Ricks design. Are there any similar jigs available that can be ordered?
Hanns Plag, a member of the Facebook Tormek Users group is producing Gordy's jig, in Germany. There is a link to his web page in his post about it (https://www.facebook.com/groups/272080627062383/permalink/593331541603955/). If one selects the jig and puts it in their cart, at checkout the site indicates it cannot ship to the USA, but conversations with Hanns on the FB page modifies that to where he allows that he can probably just ship by normal postal methods. One would have to PM him to work that out.
Rick
Quote from: RickKrung on May 22, 2020, 05:18:13 PM
Quote from: harivney on May 22, 2020, 04:59:20 PM
Quote from: wanderingwhittler on November 14, 2018, 03:29:28 AM
Hey Gord, that's really slick! Thanks for sharing the idea and instructions.
Are there any additional instructions for Gordon's jig other than comments in his post? Knife grinders stopped selling Ricks design. Are there any similar jigs available that can be ordered?
Hanns Plag, a member of the Facebook Tormek Users group is producing Gordy's jig, in Germany. There is a link to his web page in his post about it (https://www.facebook.com/groups/272080627062383/permalink/593331541603955/). If one selects the jig and puts it in their cart, at checkout the site indicates it cannot ship to the USA, but conversations with Hanns on the FB page modifies that to where he allows that he can probably just ship by normal postal methods. One would have to PM him to work that out.
Rick
Thanks. Expensive shipping. Surprised no one in the USA makes one. What is the mm diameter of the tormek knife holder shaft (I dont have tormek yet)
can someone please tell me the diameter of the shaft on Knife Blade Sharpening Jig Tormek SVM-45? I don't have tormek yet.
Quote from: harivney on May 23, 2020, 04:23:56 PM
can someone please tell me the diameter of the shaft on Knife Blade Sharpening Jig Tormek SVM-45? I don't have tormek yet.
12mm.
If you can, take a look at one of the spreadsheets or calculators you'll find in my signature... most have the dimensions of everything. :)
For example... http://sharpeninghandbook.info/indexCalcProj.html has the basics.
thank you
Quote from: cbwx34 on May 23, 2020, 05:51:44 PM
Quote from: harivney on May 23, 2020, 04:23:56 PM
can someone please tell me the diameter of the shaft on Knife Blade Sharpening Jig Tormek SVM-45? I don't have tormek yet.
12mm.
...snip...
True enough, 12mm. But the jigs are cast parts, with a parting line down both sides. Sometimes those parting lines cause binding. I've filed them down when needed.
Also, I found the shaft on my two SVD-140s to be oversize, such that my Pin Pivot Collar didn't fit very well.
Rick
I love all of this!
A simple way is drill a hole of the appropriate size through the shaft of the jig, and insert a piece of drill rod. Drill and tap a set screw to hold the drill rod. Or you can just use epoxy to glue the shaft in place.
Actually, made my own version of the SVM-45 : https://www.youtube.com/watch?v=KHrh2nmpYKU
I turned 2 knobs, one pretty flat like in the original version and another one rounded.
It works quite nice :). Hope this helps
Quote from: Dutchman on November 20, 2018, 09:52:45 AM
In order to match the jig to the curvature of the knife tip, the length of the jig should be variable, equa; to the radius of the curvature, and in any case longer than it is now. ;)
When Dutchman speaks, I listen. Until 2002, all the Tormek knife jigs were longer. Apparently, there was a problem with some users leaning on the longer jigs, so they were redesigned to their present length. The earlier jigs were around 40 mm longer, including longer threaded shafts. They also used locking screws.
I wanted a longer jig with a threaded shaft for small paring knives to reach 139mm Projection with the kenjig. I found two of them on ebay. Even though they are twenty years out of production, they show up occasionally.
Ken
Quote from: Ken S on October 14, 2021, 12:08:41 AM
Quote from: Dutchman on November 20, 2018, 09:52:45 AM
In order to match the jig to the curvature of the knife tip, the length of the jig should be variable, equa; to the radius of the curvature, and in any case longer than it is now. ;)
When Dutchman speaks, I listen. Until 2002, all the Tormek knife jigs were longer. Apparently, there was a problem with some users leaning on the longer jigs, so they were redesigned to their present length. The earlier jigs were around 40 mm longer, including longer threaded shafts. They also used locking screws.
I wanted a longer jig with a threaded shaft for small paring knives to reach 139mm Projection with the kenjig. I found two of them on ebay. Even though they are twenty years out of production, they show up occasionally.
Ken
I don't disagree with this, but I believe you can also adjust it by how far or close you clamp the "belly to tip" area, in relation to the clamp.
Quote from: Ken S on October 14, 2021, 12:08:41 AM
I wanted a longer jig with a threaded shaft for small paring knives to reach 139mm Projection with the kenjig.
Ken
I am not fully acquainted with the Kenjig, which might be apparent from what I am about to write.
My current understanding is that the 139mm was decided upon based on the range of dimensions of the particular knives that Ken was going to sharpen and not that it is some 'golden' dimension that would apply to all knives.
Of course I could be totally wrong about that, and I am perfectly happy to be corrected and to learn.
Ken (a different one :)
Ken, welcome to the forum.
While I would like to say that the 139mm number came to me in a dream, the real reason was much more practical.
At the time I designed the kenjig (originally called the KS-150) my entire collection of kitchen knives consisted of half a dozen Henckels I had had for fourteen years. All of them were traditional designs with gentle curves; I had no use for pivoting. As described in the attached instructions, I used different jigs for my eight inch chef knife, six inch slicer, and four inch paring knife. The system also works with just one SVM-45.
I learned recently that Dutchman, whose grinding angles booklet inspired the kenjig, described the process I later used for the 139mm Projection figure. While not the first to tred on this path, I at least chose a good explorer to follow.
I was originally concerned with compensating for wheel wear, and several later variations by other members incorporated automatic compensation. With constant diameter diamond wheels, this is no longer an issue. I also believe that I was overly concerned about it at the time.
I standardized at 15 degrees per side. Different angle settings are easily obtained by simply making more kenjigs.
Most people do not understand the kenjig. I believe the basic concept, while based on Dutchman's solid trig, is too simple; it flies under the radar.
Ken (the old one :)
https://www.sharpeninghandbook.info/Images/Tool-Jig-KenJig.pdf
Quote from: kenlip on December 01, 2021, 05:59:01 AM
...
My current understanding is that the 139mm was decided upon based on the range of dimensions of the particular knives that Ken was going to sharpen and not that it is some 'golden' dimension that would apply to all knives
....
The 139mm originates from my proposal on angle-adjustment in the documents you can find at the links in my signature.
You can find the following citations:
Quote
• Length between stop and clamp edge is adjustable from 108 to 125 mm
and
Quote
Consider a cooks knife with a width of 45mm. The jig can grip the knife to a depth of 14mm. As a consequence the knife edge extends 31mm from the clamp.
Thus the distance A between the knife edge and the adjustable stop can be varied between 108+31 and 125+31 mm, that is from 139mm to 156mm.
Because the adjustment range is 17mm, all knives with a width between 38 and 45mm can thus be set to a Projection distance of 139mm.
Knives with a smaller width must therefore be set to a smaller Projection and therefore also a different USB height
I would say a combined effort. ::)
Dutchman came up with this, and Ken gives him credit in his work, but as kenlip pointed out, Ken most likely "standardized" the 139mm in his Kenjig work... a measurement that worked with most of his knives.
(Or maybe this is "beyond my ken"). :D
Hello, I am a newcomer here at the Tormek Forum Community.
Thank you to everyone who is sharing their knowledge and experience.
I might have made something that can be 3D-printed, just started my printer and will know in about 50 mins if I am on to something or not.
(https://i.imgur.com/NlhabY0.png)
(https://i.imgur.com/Hn4WGVT.png)
Seems to be a working prototype, made fit for a M5 screw to tighten the pivot collar.
(https://i.imgur.com/DiOchcG.jpg?1)
(https://i.imgur.com/1PQfV7a.jpg?1)
(https://i.imgur.com/qflSqp3.jpg?1)
(https://i.imgur.com/ZpBCtHx.jpg?1)
(https://i.imgur.com/HAT4Zsw.jpg?1)
(https://i.imgur.com/1xIH6f3.jpg?1)
(https://i.imgur.com/QYY4wkE.jpg?1)
Quote from: Leap on February 02, 2022, 09:25:31 AM
Seems to be a working prototype, made fit for a M5 screw to tighten the pivot collar.
I love it! .... now I need a 3d printer and a few things to learn...