I'm thinking of making my own pivot collar to use with knife jigs. I have a lot of people wanting me to sharpen skinning knives and it's difficult with the stock jig. My plan is to weld two 1.25 inch steel bars to a 12mm clamping collar. Both the collar and the bars will be 316 stainless steel. The steel bar I plan to use is .25 inch diameter. My question is, will the .25 diameter rod work well or should it be a slightly larger diameter like says 3/8 or 1/2 inch. This question is mostly aimed at people who have either made their own pivot collar or have experience with a custom pivot collar. Any advice will be appreciated.
Thanks
Antz
Quote from: Antz on May 28, 2019, 08:42:49 AM
I'm thinking of making my own pivot collar to use with knife jigs. ...snip...
My question is, will the .25 diameter rod work well or should it be a slightly larger diameter like says 3/8 or 1/2 inch.
...snip...
Thanks
Antz
The diameter of the pins on the Pin Pivot Collar that I made is 5/16". The diameter is not at all critical, IMHO. I think the pins do not need to be anywhere near 1.25" long, if that is what that dimension is.
Also, there was an extremely ingenious alternative offered by another, fairly new to the forum user, that was just a block of metal (aluminum?) shaped into a mostly triangular cross-section with a 12mm hole cross-drilled to fit the USB. Set or thumb screw for locking it to the jig shaft. Besides being quite ingenious, it is far more simple to make than pins welded to a locking collar. I highly recommend looking into this alternative. If I were an observer at this stage, that is what I would do. It could be made from a block of hardwood or plastic.
"Here 'tis"...
https://forum.tormek.com/index.php?topic=3802.msg25365#msg25365
Rick
Thanks Rick, I read the post and it gave me a lot more ideas to work with. Sorry if I asked a question that had previously been asked by other members, I probably should have spent more time looking through the forum before asking my question but I haven't seemed to able to figure out the search function all that well. The aluminum collar looks pretty easy and doable (and a great idea by the way). I see others have just glued flattened rod directly to the plastic tormek jig guide but like others have stated that forces you to work with 1/2 turns of the collar. I don't think that would be an issue though because I usually don't see the jig for adjustments, I just use the micro adjust on the universal support. I have a lot to think about now.
And since I already have this post going, does anyone know if working with a pivot instead of the basic jig is harder to keep the blade steady? I had a few mistakes with the basic jig already where I accidentally tilted my wrist and touched the blade to the edge of the wheel. No big deal, couple more passes and I could even everything out but still frustrating. Wondering if the pivot will exacerbate those types of issues. Sorry for the long post.
Thanks
Antz
Quote from: Antz on May 28, 2019, 10:46:57 PM
...snip...
And since I already have this post going, does anyone know if working with a pivot instead of the basic jig is harder to keep the blade steady? I had a few mistakes with the basic jig already where I accidentally tilted my wrist and touched the blade to the edge of the wheel. No big deal, couple more passes and I could even everything out but still frustrating. Wondering if the pivot will exacerbate those types of issues. Sorry for the long post.
Thanks
Antz
I do not now find the pivot collar to be more difficult to keep the blade steady. I also had and sometimes still do have some slips, but that happens with either collar. I think it is just a matter of time of you developing the technique and muscle memory for using the jig with whatever collar. I want to stress the muscle memory aspect. I think it is crucial. And I think it is crucial to learn to do it slow, controlled and methodical. It will greatly improve the quality of your results and reduce the "slips" and mine are mainly due now to inattentiveness.
Thanks again Rick! Yes I agree, I'm still developing the muscle memory. I am getting better with each knife I sharpen and the slips are becoming fewer. Also I have decided to make my pivot collar with 12mm clamping collars and 3/8" stainless steel pins welded. I would have done the aluminum block method except I don't have aluminum and I just so happen to have the clamping collars and rod readily available to me. I know I could have made it out of wood but I just like the look and longevity of stainless steel. I'll post some pictures when it's complete. I might make a few extra if they turn out good. If I do I can send them to whoever wants one and hopefully make some friends here on the forum ;D
I tried to make the wedge jig with Delrin plastic. It is hard, but not enough. Chalked that up to a learning experience.
Kind regards,
Rich
So I finally got around to completing my pivot collar. Welded some 316 stainless steel rod to a 12mm 316 stainless clamping collar. It wasn't to hard for my first try. Here's some pics. I tried it out on several knives it works great. Much easier to get even bevels all the way to the tip. Thank you all for your advice and for paving the way for people like me.
Thanks,
Antz
Is this post related to the one by Riverman? Are you trying to achieve an equal bevel on both sides of the knife edge? Just a thought from looking at your pictures. I wonder if the reason for the inequality of the bevel is the relieved portion of the jig on the clamp that enables better holding of the knife blade. Since the unequal bevel is small and the relief is small, are they related? Relieve the other side as well and see if that does not equal things out. I have not attempted this but it seems as though it should work. It might disable holding smaller knife blades but only the smallest like a pen knife or paring knife.
Jeff,
This post is not related to rivermans post. The pivot collar is just to better pivot the jig on the support bar to get the tips of curved blades such as skinners more evenly. About the self centering jigs and the uneven bevel issues with thicker knives, you are correct that it is directly related to the milled portion of the knife jig. Any blade thicker than roughly 3mm you start getting uneven bevels and it just runs away from there the thicker the blade is. Wootz I think had a post about having a set of SVM-45 jigs that he had custom milled to different relief Depths for different blade thicknesses. If I find it I'll update this post with the link. There are also other members that have made their own versions of a self centering jig.
Antz
Ps: I know the welds on my pivot collar are horrible! But it works!
Here is my 2nd attempt at making a pivot collar. The weld are a lot cleaner and filled in. Works great.
Here's some pictures
Antz
Antz,
Nice work. You will like this update to the knife jig.
Kind regards,
Rich
Quote from: Antz on June 21, 2019, 05:44:50 AM
So I finally got around to completing my pivot collar. Welded some 316 stainless steel rod to a 12mm 316 stainless clamping collar. It wasn't to hard for my first try. Here's some pics. I tried it out on several knives it works great. Much easier to get even bevels all the way to the tip. Thank you all for your advice and for paving the way for people like me.
Thanks,
Antz
Well done!, where did you get your 12mm clamping collar from? and did you use Mig, Tig or Arc?
Thanks Mat,
I got the clamping collar from grainger. https://m.grainger.com/mobile/product/RULAND-MANUFACTURING-316-Stainless-Steel-Shaft-30VK80?breadcrumbCatId=5258&fc=MWP2IDP2PCP
The rod was from amazon, just a 3/8" 316 stainless steel rod 1 foot length (about 12$ US). I think you can also get the clamping collar directly from Ruland but it's more expensive. I TiG welded it with 316 filler. My first attempt wasn't that nice looking but still very functional. My second attempt came out really nice. If you buy a one foot rod you can make about 6 clamping collars. I would suggest getting several collars Incase the first one dosnt turn out well. Total coast is about the same as a brand new SVM-45.
Antz
Ps: it can be kind of tricky but if you have any welding experience it should be no problem. I also buffed it with a dremel after welding with a felt wheel loaded with the tormek compound.
Antz, It looks like it would be about $75 for me to make this collar today. Do you think the 316L was worth it?
Quote from: davidapplewhite on October 09, 2021, 05:54:58 PM
Antz, It looks like it would be about $75 for me to make this collar today. Do you think the 316L was worth it?
Pivot collars are nice, but just using a shaft collar like this one...
https://www.mcmaster.com/9506T6/
... works well. I have a pivot collar, but put the shaft collar on a while ago to take a picture, and never even switched back. In most cases, works just fine.
(https://forum.tormek.com/index.php?action=dlattach;topic=3977.0;attach=5934)
All you need is something that reduces the width of the stock collar.
I have never needed a pivot collar, although I do have a couple. (My knives are mostly straight kitchen knives and traditional pocket knives.) That said, I believe any of the pivot designs in this topic should work well.
From working with the kenjig for many years, I have become very aware of the relationship between Projection and Distance. I believe in using whichever is easier. With a pivot collar, adjusting the Distance between the grinding wheel and the support bar might be easier than fiddling with the adjustable stop for a fine adjustment. Your call; it's nice to have choices.
Ken
Why not continue the threads down the shaft by using a die?
Good thought, however, the threads on the knife jig shafts are a non standard size. They are also a non standard shape. And, the new jig design with the O ring will only work with a shorter thread length.
Ken
It also seems to me that the pivot collar solves the annoying tendancy of the stock collar to rotate, changing the projection length.
This looks interesting, but I'm not exactly sure I understand what it does... Is this just a more stable version of the built-in handle? Or does it help with the end stroke where you need to pivot up for the knife tip? Is there a video of one of these in action?
Quote from: Rimu on October 13, 2021, 09:55:50 AM
This looks interesting, but I'm not exactly sure I understand what it does... Is this just a more stable version of the built-in handle? Or does it help with the end stroke where you need to pivot up for the knife tip? Is there a video of one of these in action?
Ton of info in this thread.... worth the read (but start on p.5 if you just want the reason behind the smaller collar).
https://forum.tormek.com/index.php?topic=2589.0
Quote from: tgbto on October 13, 2021, 08:20:15 AM
It also seems to me that the pivot collar solves the annoying tendancy of the stock collar to rotate, changing the projection length.
I wrapped some painters tape on the jig, then screwed the stop collar on over it, to avoid this (when I used the stock collar).
Quote from: tgbto on October 13, 2021, 08:20:15 AM
It also seems to me that the pivot collar solves the annoying tendancy of the stock collar to rotate, changing the projection length.
It took me a bit to (think) I understand this statement. Are you saying that the stock collar, the type with the O-ring friction tends to rotate on the shaft, thus causing it to move up or down on the shaft, which results in a change in projection length? If so, I agree that tendency is annoying. I solved it by buying Tormek extra locking knobs and drilling/tapping the collar so the collar can be positively locked in place. This means removing and not using the O-ring. This is the way the collar used to be, until Tormek changed to the O-ring.
The thing that was a little confusing for me about the statement is that the point of the pivot collar is so you can pivot in order to better maintain a projection closer to the one set by the collar.
Rick
Just posted on another topic an alternative to this.
Wouldn't it be easier for those who haven't the financial condition just to turn 2 wood "knobs" and round their base so it can pivot.
I made (I tried at least) my own version of it. Made 2 wood "knobs". One flat and one rounded for the exact purpose of this topic :)
Although it does not worth the effort making the whole version of the SVM-45, it totally worths just turning the 2 knobs.
https://www.youtube.com/watch?v=KHrh2nmpYKU
Quote from: Guelgo on October 13, 2021, 10:38:50 PM
Just posted on another topic an alternative to this.
Wouldn't it be easier for those who haven't the financial condition just to turn 2 wood "knobs" and round their base so it can pivot.
I made (I tried at least) my own version of it. Made 2 wood "knobs". One flat and one rounded for the exact purpose of this topic :)
Although it does not worth the effort making the whole version of the SVM-45, it totally worths just turning the 2 knobs.
https://www.youtube.com/watch?v=KHrh2nmpYKU
Cheapest (I think) is probably a shaft collar I posted before... https://www.mcmaster.com/9506T6/
You can also cut the sides off the stock collar (some examples in this thread).... https://forum.tormek.com/index.php?topic=3522
But if you have the skill and tools, your examples look good! :)
Quote from: RickKrung on October 13, 2021, 03:16:02 PM
Quote from: tgbto on October 13, 2021, 08:20:15 AM
It also seems to me that the pivot collar solves the annoying tendancy of the stock collar to rotate, changing the projection length.
It took me a bit to (think) I understand this statement. Are you saying that the stock collar, the type with the O-ring friction tends to rotate on the shaft, thus causing it to move up or down on the shaft, which results in a change in projection length? If so, I agree that tendency is annoying.
Rick
Exactly! And I will try taping over the thread, to see if it improves things...