USB Height Setting Using Wootz's Applet

[RickKrung]

Wootz,

I know that your applet uses the top of the machine case as the reference point for setting the height of the USB. I also know a major interest in you developing that applet was to increase accuracy in setting the bevel angle. 

I have been somewhat casually setting the angle, using a pattern makers marking gage, not paying much attention to exactly where on the case top that I was referencing from.  Not having calipers long enough to work directly in mm, I use my 12" calipers, convert units, set the calipers and then set the marking gage and then use the gage to set the USB.  Pain in the ass, but its what I have.  I have tried using the calipers directly, but they don't quite reach the top of the USB.  Thus, the marking gage.  Nice big wide flange. 


I noticed today that the case from a very short distance away from the mount base is sloped.  Makes sense for water drainage.  Slopes from about 168.7mm at the top to about 172.1 at the edge near the stone.  That is a lot. 


I started trying different locations, to get away from that slope.  I settled on in front of it, between the mount base and the lifting handle.  There is a good flat area there, which is where I rest the end of the marking gage with the large flange above the USB.  To set the USB height, I start with the USB below and clear of the gage flange. Then start raising the USB using the micro-adjust.  I tilt the gage left and right as I raise the USB until the tilting stops.  That is top dead center and the proper height.  Then lock the screws.  I am much happier with this procedure.


Rick

[Crusty]

I also use Wootz program.
I also use the housing on front of the USB although I use a sliding combination square to set the height, the end of which is square to the top of the housing, maybe not as accurate as callipers but getting close.

[wootz]

The applet sets grinding angle by vertical distance from the top of the Universal Support bar to a flat area on the top of the housing near the vertical sleeves.
I also drop a perpendicular in front of the Universal Support - as shown for T-8/4 and T-7, but most important for consistency is using the same spot on a perpendicular from the US bar and the same instrument to measure the distance.

T-8 and T-4


T-7


E.g. to finish a knife within 5 min we save time on changing wheels, and have a coarse wheel on T-7 and fine wheel on T8, then deburr on paper wheels, and this software allows to maintain the same grinding/honing angle on all.

Another way to save time is using 2 wheels on a single Tormek machine, one coarse and the other fine, rather than grading the same wheel fine/coarse - and this applet maintains the same grinding angle on wheels of different diameter.

Suppose you aim at a 30 degrees included edge.
Should that spot on the housing you use to set the grinding angle be not in a flat area, or your measuring instrument be not of the ultimate precision, no one gives a hoot or two hoots if your grinding angle is 15.1 degrees and not 15. What matters is that having changed to a finer wheel you continue grinding at the same 15.1 degrees - and that's what this applet does for you.
At this moment, as SEM shows for grit # 800-1000, your edge apex comes to 0.1-0.2 micron width (for comparison, a Gillette razor edge is 0.1)
Use the applet again to maintain the same angle as you deburr on SJ wheel to get a straight razor sharpness on your knife edge.

We don't have a T-4 in our workshop, and I take this opportunity to thank Curtis (cbwx34) for his help with tuning the applet for it.

[cbwx34]

but most important for consistency is using the same spot on a perpendicular from the US bar.

Worth highlighting this small, but very important point.  Consistency is sometimes more important (or at least just as) than accuracy.

If only there was a scale of some sort directly on the USB...

[Ken S]

I learned a very simple way to set the USB Distance from Steve Bottorff. This is used with the horizontal position, which is what Steve uses for knives. Steve places his index finger over the end of the USB sleeve and places the USB. The Distance is when the end of the USB meets his fingertip. This Distance doesn't work for everything, however, when it does, set up is very fast.

Calibrating the USB would be nice, however, as the grinding wheel diameter changes, the scale reference point would also need to change. 

Ken

[cbwx34]

I learned a very simple way to set the USB Distance from Steve Bottorff. This is used with the horizontal position, which is what Steve uses for knives. Steve places his index finger over the end of the USB sleeve and places the USB. The Distance is when the end of the USB meets his fingertip. This Distance doesn't work for everything, however, when it does, set up is very fast.

Calibrating the USB would be nice, however, as the grinding wheel diameter changes, the scale reference point would also need to change. 

Ken

I'm thinking a measuring scale on the USB.  If it were 'calibrated' against something like wootz's program... it would make setup a breeze.  For example, I did a quick calculation in wootz's program... for the T-4:  Wheel 200mm / Projection Dist. 141mm / Angle 20° = USB height of 167.5mm.  If I had measurement markings on the USB in 5mm increments (referenced from the top of the casing, like the program does now)...



... this would get me close.  A quick check showed that 20 'clicks' on the micro adjust (each number on the micro-adjust is a 'click') = 5mm change... so 4 clicks = 1mm... anyway 10 clicks would put me right at 167.5.

Wheel size wouldn't matter, since it's accounted for in the program.

(Peer review time...).

p.s.  (Don't etch these numbers, like the "clicks" in stone, I was doing a quick setup to show what I meant). 

[wootz]

Today my son shot me using the applet, and finally I have a video on the need of which Ken has been telling me since mid last year - will upload to YouTube tomorrow.

[Ken S]

Wootz, once again you inspire me to move forward. I look forward to your video!

Ken

[wootz]

Videos showing sharpening on Tormek using our applet, and BESS testing:

https://youtu.be/OvYN0jx_Hik

https://youtu.be/ZDPXqAK9Xr0

Where it seems inappropriate to older generation, it is meant to be entertaining...
As to the quality - shot and edited by my 11-year son on his iPad.

[cbwx34]

Video showing sharpening on Tormek using our applet, and BESS testing:
https://youtu.be/OvYN0jx_Hik

Where it seems inappropriate to older generation, it is meant to be entertaining...
As to the quality - shot and edited by my 11-year son on his iPad.

Nice to see it implemented in an "actual use" video, and not just a quick demo.

(I did spend the first minute checking the volume... so worth mentioning there's no sound). 

Walter would be proud.

[wootz]

Actually, the sound is there where the actual sharpening is happening.
Funnily enough how this video made me recognize the amount of preliminaries.
Rephrasing the Abraham Lincoln's quotation about sharpening the axe, "If I were given six minutes to sharpen a knife, I would spend the first five in preparation."

[cbwx34]

Actually, the sound is there where the actual sharpening is happening.
Funnily enough how this video made me recognize the amount of preliminaries.
Rephrasing the Abraham Lincoln's quotation about sharpening the axe, "If I were given six minutes to sharpen a knife, I would spend the first five in preparation."

Ok Mr. picky...

Nice to see it implemented in an "actual use" video, and not just a quick demo.

(I did spend the first minute checking the volume... so worth mentioning there's no sound at the beginning). 

Walter would be proud.

[cbwx34]

I'm thinking a measuring scale on the USB.  If it were 'calibrated' against something like wootz's program... it would make setup a breeze. 

So, I was doing some other testing, and actually set this up to work today...



It's 'calibrated' to work with Wootz program.  This time I did the math.  (But as always, double check).

The thread pitch on the USB is 1.5mm, so I would make marks every 3mm.  (The picture is a sample). Each mark on the micro adjust is .25mm, so 4 marks or 'clicks' = 1mm.  At every 3mm mark the '6' on the Micro Adjust was at the 12 o'clock position, so it was easy enough to "dial in" whatever angle I wanted.  If you want a starting point... '150' is 42mm from the bottom of the USB post.  I used the post on the machine as 'straight edge' for the Sharpie.

After a while, I could easily "dial in" greater distances, so I'm thinking marks every 6mm would be easily sufficient.

I found it easier than using a caliper... or at least an alternative... especially on calculations that were larger than my caliper would reach.  I would periodically check it with a caliper... and would typically be within a few hundredths.  (Close enough for government work). 

(Now I just need to not stand and try and write the numbers, while holding the USB). 

Let the Sharpie sit overnight, and it stays on pretty well... (found out when I was cleaning off the other marks I made). 

[wootz]

Curtis, I believe in mental connections through noosphere or whatever, and there is definitely some sort of link between our two minds, as you often voice what I've been thinking about, like now.

The Universal Support positioning in the vertical sleeves keeps returning to my thoughts, and my thoughts keep returning to a scale on the Universal Support similar to what you've just described, and some driving mechanism for it in the vertical sleeves to eliminate the play and add to precision.
This is the last area left for Tormek to improve to make this sharpener truly precise - in addition to the self-centering knife jig of course.

Unfortunately, I do not see this happening in the medium future.
Risking to be banned here, I will still say what I see.

The cast aluminium top of the T-8 is a design failure.
Not only it worsened the Universal Support mount precision, as its play in the oval-shaped sleeves has become worse than it was in T-7, but also deprived users from ability to screw-in attachments to the top - we could do it with the T-7 steel flat top, but can not now.

Precluding further improvements, the full-cast housing is a dead-end.
Practicality has worsened, as the magnet base devices can't be used with it anymore, even the AngleMaster.

The water trough in T-8 is a great improvement, but honestly they'd rather direct their development funds to solve imprecision of the Universal Support mount, as it is the foundation of all jigs precision.

Interestingly, I found the USB holes on the machine case to be different (I have a T-8).  The ones closest to the grinding wheel were fairly consistent, 0.477" (12.12mm).  But the USB holes away from the grinding wheel were larger, closer to 0.5" (12.5mm) and much less consistent. (These were measured using a machinist telescoping gage, so it is as precise as I can get without resorting to gage pins, which I have.)

Rick

[Ken S]

From the Office of the Moderator:

Mr. Wootz, you are forthwith banned from the forum for life.

Just kidding. Speaking only for myself, I welcome honest constructive criticism on the forum. However, if you are not careful, you will unseat me as the Chief Critic. I also consider myself the Head Cheerleader. There are many things I like about the Tormek. I do not see any of the clones as peers in either quality or innovation. That does not mean that I see no room for improvement.

As moderator and a member, I do not want to see vindictive criticism of the Tormek on the forum. That is not the same as well intentioned constructive comments.

Keep posting.

Ken

I originally intended this post to compliment your well done video. I appreciate that you made it long enough to let your message sink in. Some of us have attention spans longer than thirty seconds and don't need canned bumper music or tricky graphics. (Oops, maybe I just got myself banned from you tube......)

Your good work is appreciated!