Messages

[cbwx34]

Your posts should now come with a warning... like the ones in an infomercial.  They are simply marketing.  I doubt you can prove that it is "more accurate"... only that it works better for you.  (But I digress...).

I've had enough of this gentleman. Unless cbwx34 is banned from the Tormek forum, I am not posting any more.

4-5 years ago when developing our software, we chose measuring to the Tormek housing rather than to the wheel for 2 reasons:
- dropping a perpendicular from the universal support to the flat of the Tormek housing is more easy and accurate than to the wheel;
- we use a depth probe for measuring the distance, and poking the calipers' depth probe into the grinding wheel damages the probe.

And when later we developed our Frontal Vertical Base and extended our software to the Tormek honing wheel, felt wheels, and to paper wheels, we saw that ours was the right approach.
It would be even more difficult to accurately measure a perpendicular to the honing wheel.

All that said, without Dutchman's genius nothing would be possible. Even though prof. Verhoeven gave first formulas for setting grinding angle on Tormek, it was Ton Nillesen from Netherlands, who gave us all the detailed trigonometry of Tormek. We only computerised our version of it.
Ton showed everyone the way.

Scratches left in steel by an abrasive particle are always smaller in width than the size of that particle.
In order to form a scratch, sufficient pressure must be exerted by the particle to exceed the yield-strength of the steel, and the abrasive particles never fully go into the steel.
The scratching is done by a small contact area of the particle.

SEM studies have shown that in fine honing relation between the size of the abrasive particle and the width of the scratches it forms is approximately 10:1

[Can we mirror finish an edge with the Tormek honing compound?]

Now let us think about this: Can we mirror finish an edge with the Tormek honing compound?

The visible light wavelength range is from 380 to 700 nanometers.

For us not to see scratches, the human eye must stop seeing light reflected by scratches, and for that the scrataches must be less than 380 nanometers wide. In microns it is less than 0.4 micron.

The honing compound grit and the size of the scratches it causes are related by about an order of magnitude, i.e. in order to get scratches under 0.4 micron wide, the honing particles must be <= 4 microns in size.

The conclusion is that the Tormek honing compound with its particles of 3-10 microns in size, can give near mirror finish, but somewhat "cloudy".
For true mirror polish we should use a finer honing, and this is done with the Tormek Japanese SJ wheel, which has grains of 2-3 microns.

The ultra sharpness we get on knives using our software for Tormek, FVB and paper wheels is in the videos on our YouTube channel https://www.youtube.com/channel/UCrs9DEOG9tHbxAH50CKINqA/videos

Users of our software for Tormek in all corners of the world get exceptional sharpness on their knives, often sharper than shaving razors, see for example:
https://www.australianbladeforums.com/vb4/knife-grinders/39276-insane-sharp-customers.html

We've put countless man-hours in testing our software accuracy: http://knifegrinders.com.au/software_testing.htm

Fine-tuning and testing this software cost me a lot, and last year I decided to make the full computer code proprietary and am not giving details in the public domain, not to feed copycats.

I happened to have micrographs of the Tormek honing compound and Autosol metal polish in the same scale.
Now we can compare their grain size.

Tormek honing compound PA-70 (microscopy by Anthony, USA):


Autosol metal polish (microscopy by Iliya, Australia):


To my eye, the particles in both are of similar size, in the range of 3 to 10 microns (not taking into account the conglomerates).
What do you see?

They have similar honing ability, but in my experience the Tormek PA-70 does better at slow RPM, while the Autosol at high RPM.

Next image shows a mainstream kitchen knife sharpened on a coarse wheel of #200-300 and then deburred (polished) on the Tormek leather wheel.
Very good result telling us that we can do the majority of mainstream knives and common woodworking tools without a fine grinding wheel. A coarse and medium wheels can do the job, thanks to the honing compound working so good.



What the 2nd image also shows us is the wire edge or feather burr seen all along the apex after the honing.



We see this picture all the time, off the Tormek leather wheel, and off the paper wheels - and it tells us that the root of the burr is still there.
That is the reason we do one more step of deburring that we call "de-rooting" the burr, or "de-wiring", to get a strong clean apex.

In our routine sharpening, each knife goes from Tormek T-7 with a coarse wheel to Tormek T-8 with a medium wheel, and another T-8 with a fine wheel, then deburred on slotted paper wheels, then back to another Tormek T-7 for removing the wire edge on a felt wheel, and then back again to a finishing paper wheel  - and comes with the sharpness of 50-80 BESS.

But when I want a record sharpness of under 50 BESS, sharper than a disposable shaving razor, for better precision, I grind that knife on a single Tormek, changing wheels from coarse to fine of the same diameter. Still it then goes to paper wheels for deburring, and then to another T-7 with the felt wheel, and the finishing paper wheel.

All grinding and deburring controlled with our software.

German high-density 0.9 g/cm3 felt wheels are made by laying and using adhesives (glue) between the layers - this gives them the abnormally high density.
United Kingdom makes them the same way.

There is a technological limit for natural felt, and high density felt not using any glue can be reached on 1" thick wheels, but this becomes increasingly more difficult with wheels nearing 2" thickness.

Effect of the glued felt on deburring is different from the deburring protocols that we published are for natural felt wheels.
I explain all this and more in the YouTube video https://youtu.be/5iqnvD8_M2k

What's an example of needing to remove the "RPM-increaser"?  I haven't seen the need... and can't think of one where the faster Tormek needs to be slowed back down... it's still slower than most other methods.  (I still think you should call it the "speeder upper").

We get nicer bevels by grinding at low RPM pocket knives, delicate folders, and complex edge shapes like recurve blades.
We get sharper and stronger edges by finishing the grinding on fine wheels at low RPM, thanks to the low grinding speed producing a smaller burr.

[rock-hard]

You know that we've been using felt wheels in deburring/honing on Tormek for years, since 2016, checking the results with the sharpness tester.
For the best results, the felt must be rock-hard - if the felt density is just "hard", "firm" or "medium", it will round the edge and drop sharpness.
I am telling you this not to promote our rock-hard felt wheel, but to save your time and effort in experimenting with the felt on Tormek.

My first idea was to use a strip of felt glued to an MDF wheel, but when we tried flexing a rock-hard felt strip on the wheel, the strip broke. Maybe this is the reason why no one produces rock-hard felt strips - they are too dense and break on flexing.

In production of our rock-hard felt wheels, for precise centering of the 12mm arbor hole it is moulded, not drilled. QA checks that the wheel circumference is flat and square.



Testing video: https://youtu.be/-HBpsQn7frY

The price that you see on our website includes world-wide delivery.

***

We needed the "RPM-increaser" not only to grind faster, but to unleash the CBN and diamond wheels advantage.
You've heard that CBN and diamond wheels grind better than stone wheels, but that is given that the pressure on the blade is the same. Since the pressure on CBN and diamond wheels must be light, less than on the stone wheel, to see their grinding advantage we need higher RPM.

And it does "unleash" - video: https://youtu.be/c-q_AI0BD6A

Initially, we also went the "tape on the motor shaft", but with the tape we cannot as easily decrease the RPM back when we need Tormek run slow for precision grinding.
With our device, we simply unscrew the set screw and remove it.

Unfortunately, we could not find stainless steel round bars of the right diameter, and every part must be turned to meet the specs. We have it done by CNC machining to keep the costs to the minimum. The 1st batch of 100 ea. is being made, and the price will become clear as it is ready for shipment.

***
We ship world-wide at the same flat rate, no matter which country our customers live, and this is my vision of fair go for everyone.

https://bladeforums.com/threads/wheel-grind-a-straight-edge-without-overgrinding.1733595/

Thank you mate.
People have been asking for sample sharpening protocols, many offered an extra pay for them. These protocols come from years of my sharpening business. I started with higher-end "supersteel" knives, i.e. those that require special pricey equipment to sharpen, then added mainstream and knife rental. It has been a very interesting journey full of the "aha" moments. The knife edge is a fascinating mystery.

A good portion of the book can be previewed in Google Books >>

Video: https://youtu.be/TLfDeE7JRAA
Testimonials: http://knifegrinders.com.au/Book_Testimonials.htm

I had to re-upload the "knife sharpening mistakes" video, of a better quality and somewhat expanded - the new link:
https://youtu.be/kRZTiv6XVgA

I've compiled it to help a rookie not to repeat the mistakes with Tormek we've done.

[Scotty]

"made from unobtanium"

Approach to low carbon and low hardness knife steel is to NOT to use fine grinding wheel and polishing, and NOT to put an acute angle, as explained in our video https://youtu.be/t4df0tWH4kY

Scotty, your mistake is that you did this knife on the #1000 grinding wheel, and honed it on the fine paper wheel. This produces weak apex and that flimsy burr that is next to impossible to get rid of.
You  can try sharpening it on your coarse wheel #220 at 15 dps, and deburring at 17.5 degree on Tormek leather wheel with the Tormek honing paste. This should give you a reasonably stable apex of <= 150 BESS.

The sharpeners I know, measure the edge angle on each side with a laser protractor, and then grind edge bevels at the original angle each side, using our angle-setting software for Tormek

E.g. Kent (Sweden): Sharper than a razor with asymmetric grind
https://youtu.be/iQ9OQepVlR0