Lubricating the Knife Jig "O" Rings

[RickKrung]

Has anyone found it necessary or useful to lubricate the knife jig "O" rings?  The original that came on the SVM-45 (medium sized jig) became dry and very hard to rotate the stop.  Just recently, the O ring disintegrated.  I've been wanting to find a lubricant for the O rings.  I know I have some with my old Nikonos V dive camera, but it is packed away and I just have gone looking for it.  Now that the one O ring has exploded, I will go find it.  Fortunately, several months ago, I ordered several more adjustable stops for doing modification work and O rings came with them, so I at least have a ready supply of replacement O rings. 

I expect there are other lubricants that would work besides one designed for O rings, but I am not aware of what they are.  Has anyone found something suitable? 

I am uncertain about how much to use, due to the length of sliding travel the stop may go thru and I don't want lubricant all over the place. 

Rick

P.S.   I do wish that folks would include a word description of jigs mentioned (as I have done above), not just the model number because I don't know them well and have to go look them up often.

[cbwx34]

I would be hesitant to lube it... I've found the collar already slips on the O-ring.  It doesn't do a very good job of holding it.

In fact, after your post in another thread about adding tape,  I added a couple of layers of blue tape to better hold it.

I'm surprised my O-ring hasn't disintegrated like yours.  They usually don't last long in a dry climate.

(Hopefully Tormek will design this back out).

[RickKrung]

I would be hesitant to lube it... I've found the collar already slips on the O-ring.  It doesn't do a very good job of holding it.

In fact, after your post in another thread about adding tape,  I added a couple of layers of blue tape to better hold it.

I'm surprised my O-ring hasn't disintegrated like yours.  They usually don't last long in a dry climate.

(Hopefully Tormek will design this back out).

Yes, of course, I was forgetting how the O rings are not really effective at maintaining the stop location already and wasn't thinking of how much worse it would be with lubrication.  But, to that end, when I ordered the extra stops (three), I ordered five of the older style locking knobs that have been replaced by the O rings.  For the purpose of installing them on the stops as positive stops. 


I'll maintain the O rings for spacing and stabilization, so in that context, I believe I will lubricate.  But without the locking knobs, I would not. 

Rick

[cbwx34]

You always inspire me...



... (although I need to cut the collar down). 

[RickKrung]

You always inspire me...

Nice.

... (although I need to cut the collar down). 

I don't think you need to cut it down, at least for use directly on the USB.  You have your version of the collar stop and soon my version of the pin pivot clamp collar will be available.  I think the cut down collars are too prone to slipping over the USB because they don't extend below the USB centerline.  Your clamp collar partially solves that but the pin pivot collar definitely solves it.  But, as Wootz said to me in a PM, the pin pivot collar is not for use on all knives, that the stock adj. collar still has lots of uses. 

You saw that I have two versions of the cut down collars.  The only way in which I will use them is as backup for the pin pivot clamp collar, for position setting and support.  The longer one gives a better grip and would be used with narrow knives where the collar is further down the shaft.  The shorter one for wider knives where the collar is further up. 

Rick

[cbwx34]

I don't think you need to cut it down, at least for use directly on the USB.  You have your version of the collar stop and soon my version of the pin pivot clamp collar will be available.  I think the cut down collars are too prone to slipping over the USB because they don't extend below the USB centerline.  Your clamp collar partially solves that but the pin pivot collar definitely solves it.  But, as Wootz said to me in a PM, the pin pivot collar is not for use on all knives, that the stock adj. collar still has lots of uses. 

You saw that I have two versions of the cut down collars.  The only way in which I will use them is as backup for the pin pivot clamp collar, for position setting and support.  The longer one gives a better grip and would be used with narrow knives where the collar is further down the shaft.  The shorter one for wider knives where the collar is further up. 

Rick

Oh yes I do!

The collar slipping over the USB hasn't been an issue for me... I think I learned long ago, (before even cutting the collar down), to keep my thumb on the back of the jig to keep better contact with the USB, since the wheel has the ability to "push" the blade up.  So no problem there.  I also think that, while there may be a few knives that benefit from the collar, (I'm guessing long straight blades), those are easy to deal with.  More benefit from no collar, IMO.  So, collar... be gone!

Glad to see you're moving forward with making your version... looking forward to it!

[Ken S]

My first exposure to knife sharpening with a Tormek was the video that Jeff Farris made many years ago. Jeff explained that the way to sharpen the point was to lift the knife, not rotate it. Because of that, I could not understand the purpose of the radius on the adjustable stop. I have always thought a larger flat surface would work better.

In my mind, the problem is that all knives do not have a uniform shape. Because of that, I do not think any shape collar is ideal for every knife. My flat idea might be useful for essentially straight knives, but would probably be far less than ideal for other shapes.

The Tormek collar strikes me as a "one size fits all" compromise. I believe Tormek has correctly surmised that the majority of customers would not choose to pay more for knife jigs with multiple collars. Therefore, we end up with one collar which works reasonably well with all knives.

We always have the option of custom machining a set of collars.

For those who miss the locking screw of the older design, adding a locking screw by drilling and tapping is a very minor project.

Tormek is not alone in this. Automobile manufacturers design their cars to satisfy the general public. Custom shops take things from there for discriminating customers. Top flite target shooters generally use customized pistols.

We are not the typical market for Tormek. However, I do believe that the typical customer will benefit from our work. We must continue.

Ken

[cbwx34]

...
In my mind, the problem is that all knives do not have a uniform shape. Because of that, I do not think any shape collar is ideal for every knife. My flat idea might be useful for essentially straight knives, but would probably be far less than ideal for other shapes.

The Tormek collar strikes me as a "one size fits all" compromise. I believe Tormek has correctly surmised that the majority of customers would not choose to pay more for knife jigs with multiple collars. Therefore, we end up with one collar which works reasonably well with all knives.
...

For me, a smaller pivot point better equates to  a "one size fits all"... it allows me to better follow the shape of the blade.  I wonder if putting the wide collar on became more of a "safety" feature, vs. a "best fit" feature?

At any rate, I managed to cut the collar off the jig...



... censored?  Well, let's just say, where some have "elegant" solutions/tools for removing the collar... mine involved "aviation snips" and a dremel.    (Then I got a life lesson on how fast a felt wheel can "eat" plastic...).    So, I figured some of you may not want to see the result, (although maybe not as bad as it sounds.)  But the face is even and smooth... all that matters I guess.  Although, I thought the flat face, might be a little more secure than the curved one kavik did, in use, I really can't tell the difference.  Probably because, as Rick stated, not a lot actually contacts the USB.

...
For those who miss the locking screw of the older design, adding a locking screw by drilling and tapping is a very minor project.

Shouldn't have to be done at this quality level/price point... and it's not a question of "missing" it... the locking screw was a better solution.  The O-ring isn't as secure (although, without the collar, less likely to move...)

[Ken S]

Just for the record, the moderator did not censor the photo.......

You may be right about a safety factor being part of a larger collar. My first T7 had the older switch. I purchased a foot switch to improve grinding on the side of the wheel. Before I had a chance to use it, my T7 was stolen. The T7 I purchased as a replacement came with the new and improved switch, which does not work with a foot switch. I am convinced that the reason for the new switch is to comply with some safety regulation mandating that the switch remain off if power is lost. While this seems an excellent regulation for safety with a tool with an exposed blade like a table saw or a bandsaw, it seems overkill for such a dangerous tool as a Tormek.

Your idea of a smaller collar may be perceived to require a higher than desired level of skill, not good for marketing any product today.

Ken

[cbwx34]

Just for the record, the moderator did not censor the photo.......

You may be right about a safety factor being part of a larger collar. My first T7 had the older switch. I purchased a foot switch to improve grinding on the side of the wheel. Before I had a chance to use it, my T7 was stolen. The T7 I purchased as a replacement came with the new and improved switch, which does not work with a foot switch. I am convinced that the reason for the new switch is to comply with some safety regulation mandating that the switch remain off if power is lost. While this seems an excellent regulation for safety with a tool with an exposed blade like a table saw or a bandsaw, it seems overkill for such a dangerous tool as a Tormek.

Your idea of a smaller collar may be perceived to require a higher than desired level of skill, not good for marketing any product today.

Ken

I was going to write "Too Embarrassed to Show"... but Censored was easier.

You're right, it does seem like the smaller collar would be harder to use, but in reality, I don't find it that way.  Like I said earlier, keeping my thumb on the back of the jig (which is what Jeff does in his knife sharpening video, btw) keeps the jig on the USB.  Rick's design may further reduce any chance of "slipping over" the USB.  (And like you say... a good sharpening video would certainly help)...

[RickKrung]

...snip...
Rick's design may further reduce any chance of "slipping over" the USB. 
...snip...

IMHO, no "may" about it.  While I can't say it totally eliminates slipping over the USB, it would take a lot of lifting (wrongly) to slip over the USB.  Thumb on the collar/USB is still needed to keep the jig from kicking back.  I just watched the video and while Jeff does hold his thumb on the "head", if he mentioned it, I didn't catch it. 

Rick

[cbwx34]

IMHO, no "may" about it.  While I can't say it totally eliminates slipping over the USB, it would take a lot of lifting (wrongly) to slip over the USB.  Thumb on the collar/USB is still needed to keep the jig from kicking back.  I just watched the video and while Jeff does hold his thumb on the "head", if he mentioned it, I didn't catch it. 

Rick

It's actually in the manual...

[wootz]

I am yet to try the Curtis/Kavik/Rick modified knife jig, and can only talk a priori.

Tormek unmodified collar appears to be better for:
- knives with a straight edge (sheepsfoot, wharncliffe and alike);
- knives which profile is a normal sweeping curve like the majority of kitchen and utility knives;
- grinding away from the wheel - if you don't pay attention, even the regular collar may be dragged over the support bar by the wheel, let alone the reduced.

Curtis/Kavik/Rick modified knife jig should be better for:
- knives with a curved belly;
- knives having the tip segment steeply curved upwards;
- blades with pronounced convexity, concavity and S-shaped.

As to the O-ring vs screw-lockable collar, the latter has advantage only when used with the O-ring.
If you've tried the older knife jig without the O-ring, locking the projection is a pain.
The jig with the O-ring is way easier to handle, but it may lose its initial position in the process of sharpening, in a some multi-step protocol especially.

[Ken S]

CB,

Please keep in mind that your thumb has been hanging around a usb and knife jigs longer than the average Tormeker.

Ken

[cbwx34]

CB,

Please keep in mind that your thumb has been hanging around a usb and knife jigs longer than the average Tormeker.

Ken

Mainly pointing out that the "thumb on the jig" isn't a technique I had to develop for the modified collar... it's SOP.

BTW, I'd like to say I learned it from the book or video, but the reality, I learned it the first time the jig started 'climbing' up the USB, and I said... Oooo, better stick my thumb there to stop that.... 

I am yet to try the Curtis/Kavik/Rick modified knife jig, and can only talk a priori.

Tormek unmodified collar appears to be better for:
- knives with a straight edge (sheepsfoot, wharncliffe and alike);
- knives which profile is a normal sweeping curve like the majority of kitchen and utility knives;
- grinding away from the wheel - if you don't pay attention, even the regular collar may be dragged over the support bar by the wheel, let alone the reduced.

Curtis/Kavik/Rick modified knife jig should be better for:
- knives with a curved belly;
- knives having the tip segment steeply curved upwards;
- blades with pronounced convexity, concavity and S-shaped.

As to the O-ring vs screw-lockable collar, the latter has advantage only when used with the O-ring.
If you've tried the older knife jig without the O-ring, locking the projection is a pain.
The jig with the O-ring is way easier to handle, but it may lose its initial position in the process of sharpening, in a some multi-step protocol especially.

Hopefully, you'll also try the "4-Stop Collar" setup at some point.  I actually like it the best, and if/when the USB-400 arrives, I may solve the "running out of room" issue with longer blades.  (Or may just use the cut down collar).

My .02... the only real advantage of the stock collar, may be straight blades.

Can't really comment about the older collar being difficult to set the projection... I rarely used it.  Just don't like the new collar turning without my consent.