BESS Score Decrease Due to Using Multiple Tormeks?

[wootz]

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.

[BeSharp]

...snip...
I live (rent) in a rather ritzy area in Vancouver (average house price: $2.5 million). I would guesstimate my sharpening as 70% Henckels / Wusthof, 20% Global, and the rest Boker, Benchmade, Opinel, Shun, etc. So good quality steel from customers who have money. Sharpening prices are not a predominant concern (I have raised prices three times in six months with no decrease in business).
...snip...

BC, Canada or WA, USA?  Or somewhere other?

What are you charging?
Rick

I'm in Vancouver, B.C., Canada, eh. Charging $1 an inch, $2 an inch for high end steel or serrated.

[BeSharp]

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 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.

Thanks Vadim. This is the kind of response I was looking for - from someone who has multiple Tormeks, and has measured the results.

Looks like I'll be ordering two more Tormeks!

[cbwx34]

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 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.

This software? 

Seems like if you want to bring up your software... you should address the issues, that's what a forum is for....

And now I have a followup question... if your software is accurate to 0.1 degree... why do you have to use just a single Tormek "for better precision"?  One of your reasons you state you use your updated software...

...
Our software update is not only for the sake of the edge angle accuracy, but for better matching the grinding and honing angles to get a sharper edge.
....

... seems a bit of a contradiction.  (I didn't add the bold on this one).

[Jan]

CB, you are correct, I agree with you.

The updated KG software uses the old, approximative Dutchman formula. For input parameters 250 mm, 139 mm and 12⁰ the top USB – stone distance is biased by 1 mm which means that the grinding angle is biased by 0.7⁰ per site.

If we add the strange jumps depending on the thickness behind the edge the bias of the grinding angle increases to some 1⁰. It is definitively not sufficient accuracy for setup of multiple Tormeks for advanced deburring.

Nevertheless when all your wheels have the same diameter you will get consistent results and small BESS score.

Jan

[wootz]

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.

[cbwx34]

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'm not sure if you read my other post, but your code was dumped into the forum a while back.  So, it's no longer a secret.

So, it leaves the questions I asked earlier worth answering.  Even if the code wasn't there... the questions remain.

Users "get exceptional sharpness", but it doesn't really have anything to do with software, as much as just the simple long tested process of creating a burr and removing it.  There's some validity to the process... but it's been around for a long time... not really new.

Bummer you spent a lot time and money, 'cause it looks like there's a flaw in the testing.  (The bad part of "going it alone" I suppose). 

[jvh]

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

Hello,

I don't want to waste too much time on already proven problems, but measured data...

Accuracy of CATRA HobbiGoni is declared ±2°, not ±0,2° as is written in your web, please correct it.
This model seems to be discontinued, specification on Catra web isn't anymore, but it can be found elsewhere. New model Portable Laser Goniometer Mk2 LP (Unfocused) has declared accuracy ±1° (and the price is about 500$).

Sharpening on "rounded" wheel produces deviations between angle at the edge apex and angle at the edge heel, see EdgeCalc (part of TormekCalc²) for more information. There are no deviations in your measurements but they must be there, because it's not flat grind. Eg. difference between apex/heel angle on 250 mm wheel, for 3 mm thick blade and double bevel (symmetrical) grind, 20° per side, is 20°/21,92°. Average deviation apex vs. heel angle is 20,96°.

EdgeCalc proves that there is no dependence of edge angle vs. blade thickness. All deviations are caused by "roundness" of the used wheel only (ideal situation with error-free measurement). It means that you get exact angle at apex, but it will vary on other parts of the edge and the highest angle will be on the edge heel. If you try to compensate it, you will get different angle on apex. Again, there's no trace of that in your data.

In view of the above and because approximative formula was confirmed in your software, I cannot take measured data seriously, sorry. It's not test of software accuracy for me, but it can be taken as grinding consistency check for a row of wheels with diameter near 250 mm (250, 260, 256, 251, 247, 10"=254 mm). I don't count Tormek leather wheel, because it's flexible and it fits into the grind surface made on a bigger wheel.

BTW: This knife wasn't very well centered in the jig.


jvh