Tormek Community

In the Shop => Knife Sharpening => Topic started by: wootz on October 15, 2019, 08:42:11 am

Title: Grinding software upgrade is coming
Post by: wootz on October 15, 2019, 08:42:11 am
NEED FOR UPGRADE
In its current form, our software sets an accurate grinding angle for resharpening a knife with established bevels at the existing edge angle.
E.g. you resharpen a 15 degrees per side (dps) knife to the same 15 dps.

However, when grinding new bevels, sharpening a grossly dull knife or a knife blank gives an edge angle differing from the calculated target by 0.5-1.5 degree. The thicker is the blade behind the edge, and the lower is the new edge angle, the greater is the difference.

To complicate it further, when sharpening on a coarse wheel, you may get a higher than the calculated angle simply because the jig projection shortens as you grind off the apex and raise the burr.

For example, when you resharpen a thin kitchen knife on a fine wheel to the same edge angle as this knife already has, you get the edge angle within 0.1 degree of the angle calculated by our software. But when you sharpen a thick hunting knife on a coarse wheel, you get an edge angle by 0.5 degree higher if sharpened at the original edge angle, and by up to 1.5 degree higher if reprofiled to a lower angle.

If you have a laser protractor, observing how the edge angle changes in the process of shaping bevels gives a better understanding of what I am writing here.

NEW INTERFACE
The new interface has additional parameters in its "Blade" section, to address the above and improve accuracy.

(http://knifegrinders.com.au/dropbox/IF_advanced8.png)

STATUS
I've coded the computer algorithm and currently testing in sharpening blades of varying thickness.
The calculations are along the lines of the explanation given by Ton Nillesen in 2018 on the page 6 of his additional booklet that can be downloaded from our website http://knifegrinders.com.au/Manuals/Grinding_Angle_Adjustment_Booklet_2018.pdf (http://knifegrinders.com.au/Manuals/Grinding_Angle_Adjustment_Booklet_2018.pdf)

The blade position on the grinding wheel changes as the sharpening progresses, gradually lowering as the edge apex travels the distance of the blade thickness behind the edge, as shown on the following schema:
(http://knifegrinders.com.au/Equipment/knife_beveling1.jpg)

This downwards shift of the blade and the knife jig it is clamped in increases in the duller edge, the thicker blade, the coarser grinding wheel, and the lower grinding angle. If not corrected, the actual grinding angle will be differing from the target.

As I am happy with my testing, we will prepare an upgrade, first of the computer-based applications, Windows PC and MacBook, and email an upgraded download to our over 1000 customers.

I am not as sure about the mobile applets, though. iPad and tablets are no problem and we will sure upgrade them and find a way to deliver to our existing customers, but the phone screen may be too small to accommodate the additional settings.

We will also upgrade our Frontal Vertical Base software with these advanced settings. But again, the phone applets are a problem, as they hardly take even the current FVB interface.

As we all understand, this is not only about the edge angle accuracy, but for better matching the grinding and honing angle to get a sharper edge.

We will also have to update the applet manuals and our webpage with the new information.
Overall, we need about 1 month to complete this upgrade, and appreciate your patience.

Cheers, Vadim
Title: Re: Grinding software upgrade is coming
Post by: van on October 15, 2019, 08:52:54 am
Good job! we are waiting. You are great! ;D
Title: Re: Grinding software upgrade is coming
Post by: Sharpco on October 15, 2019, 09:06:37 am
Great!
Title: Re: Grinding software upgrade is coming
Post by: smurfs on October 15, 2019, 10:27:29 am
Hi Vadim,

I observed similar behaviour when I was grinding the life out of my practice chisel. This was especially noticeable when I changed from a more to less acute edge angle as more of the edge was ground away to arrive at a flat bevel. I found that in the process of grinding the jig projection length was reduced by up to 1 to 2mm, throwing out the desired bevel angle by a similar number of degrees.

In my research I too measured the thickness of the bevel at the heel and modified my projection calculation so that the correct angle was achieved at the moment of burr creation. As a sharpening novice it is pleasing to read someone else with vastly more experience has arrived at the same point with an almost identical solution.

Cheers, Andrew
Title: Re: Grinding software upgrade is coming
Post by: john.jcb on October 15, 2019, 04:49:45 pm
This will be a welcome addition. I have had several requests to change the angle on older European knives.
Title: Re: Grinding software upgrade is coming
Post by: Josu V on October 15, 2019, 09:46:22 pm
In first place, thank yoy for your work.

I will be alert for possible update for IOS app.
Please...  if necessary, I will buy a high magnification glasses in order to can see the app in my smart phone.  ;D
I always use my smart phone to calculate grinding and honing measures and find very interesting an update of the smart phone app.

Regards
Title: Re: Grinding software upgrade is coming
Post by: wootz on October 15, 2019, 10:09:08 pm
In first place, thank yoy for your work.

I will be alert for possible update for IOS app.
Please...  if necessary, I will buy a high magnification glasses in order to can see the app in my smart phone.  ;D
I always use my smart phone to calculate grinding and honing measures and find very interesting an update of the smart phone app.

Regards

 ;D
Not to worry, Josu. We are blessed to have the best mobile apps programmer, he should be able to solve it with an extra screen for the additional settings. I haven't thought much about it yet as we are in the early stages of the upgrade. I only wanted to say that as I myself program for Windows, the computer-based applet will be ready first; others will follow.
Title: Re: Grinding software upgrade is coming
Post by: wootz on October 22, 2019, 01:31:35 am
We've completed testing of our updated software, the testing process and results are shown here:
http://knifegrinders.com.au/software_testing.htm (http://knifegrinders.com.au/software_testing.htm)

It has been an exhaustive testing. I didn't count, but overall we did near 100 test sharpenings. With the amount of experimental grinding and honing we've done using the Grinding Angle Setter and the Frontal Vertical Base applets, I am confident in the accuracy of our software. Those of your who have a laser protractor will be able to confirm it yourself as we release the update.

It is clear now, that thickness behind the edge is an important parameter that should not be ignored.

The mathematical description of the grinding angle given for Tormek machine by Ton Nillesen in 2013 is using an abstract blade, thin and single-bevel. This is a normal phase in scientific thinking, as we have to abstract from real-world particulars to be able to generalize and describe the reality mathematically. That model did not take into account the thickness behind the edge. Because of that, the formulas give a systematic error for thicker blades, especially double-bevel, as Ton Nillesen explains in his additional booklet in 2018.

Our updated computer algorithm factors in the thickness behind the edge, and specifics of double-bevel edge vs single-bevel. It is more complex, but also more accurate.

This, however, does not make our applets more complex to use.
For our customers who care about the edge angle accuracy, our software gives an accurate tool.
But those of you who prefer simplicity and do not care much about 0.5 degree deviation from the target angle, can simply put number "1" in the "Blade thickness" field for thin knives, and number "2" or "3" for thick knives. I will explain this in the updated manual.

The software is now with our MacBook and mobile apps programmers, and should be released within 2 weeks from today. I will then send the update for Windows, Mac, iPhone/iPad and Android smartphone/tablets to our existing customers free of charge.


Title: Re: Grinding software upgrade is coming
Post by: Dutchman on October 22, 2019, 09:55:33 am
Thank you for mentioning the source :)
Title: Re: Grinding software upgrade is coming
Post by: Jan on October 22, 2019, 01:07:19 pm
I have shaped several blanks into blades without observing differences between the desired and sharpened bevel angle provided that the projection length has not been shortened during blank sharpening.

I use my Excel script to calculate the distance between the USB and the wheel surface. My script works without approximations.

Jan
Title: Re: Grinding software upgrade is coming
Post by: wootz on October 22, 2019, 09:12:49 pm
Jan, sharpen plate steel 1mm, 2mm and 3mm thick to the same target angle using your script, and you will see difference in the ground angle between all the three.
.
Title: Re: Grinding software upgrade is coming
Post by: Jan on October 22, 2019, 09:54:46 pm
Wootz, my experience is limited to 2.5 mm thick blanks which I shape to double-bevel blades. Blanks of this thickness are centred in the knife jig.

If the blank is not centred in the knife jig than the sharpened bevel angle will be different from the target bevel angle and even more the bevel angles will be different for each side of the blade.

Jan
 
Title: Re: Grinding software upgrade is coming
Post by: wootz on October 23, 2019, 05:38:38 am
Jan, are you implying we do not center blades in knife jigs before grinding? - we always do.
BTW, the Tormek knife jig SVM-45 centers a 2.1 mm blade, not 2.5 mm as you think.
Anyway, the blade thickness behind the edge matters for accurate calculation, even if using a self-centering jig.

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.
As you guys can see at the http://knifegrinders.com.au/software_testing.htm (http://knifegrinders.com.au/software_testing.htm) the BESS Sharpness Tester PT50 showed 60-80 BES for the 12° and 16° edge honed with the Tormek honing paste at the ground angle. This is an improvement over what we observed in the past for the knife steels used in this testing.
Title: Re: Grinding software upgrade is coming
Post by: Jan on October 23, 2019, 10:16:03 am
Wootz, thank you for ensuring me that blade centring in the knife jig is not an issue.

I am asking for clarification because I am missing some geometrical sketch or drawing which would explain the merit of the sw upgrade. Your reference to page 6 of the Ton Nillsen (2018) booklet is not fully sufficient and explanatory.

It is my great pleasure to inform you, that I have carefully reviewed the revised Ton booklet (2018) and have found, that the formula F9 used to calculate the New tables is exact, derived without any approximations.  The figures in his New tables are now identical with my calculations. For some users it might be useful to display the figures in the New tables with one or two decimal points.

The exact formula F9 replaces the original formula F1 which was an approximate one and might cause a bevel angle set-up error up to 0.7 degree per one side. The use of the approximate formula F1 could also cause some inconsistencies between grinding and honing angles.

Jan

Title: Re: Grinding software upgrade is coming
Post by: smurfs on October 23, 2019, 05:33:50 pm
Hi Vadim,

Could the angle issue simply be due to the reduction in the jig projection length during grinding, as illustrated in the schema diagram in your initial post? If it is would it not be better to recheck the projection after each grinding step in your sharpening procedure, and if necessary return to the initial projection length using the adjustable stop? Perhaps such a tweak is all that is needed to ensure the target edge angle is always maintained.

Or may be I've missed something and it is not as straightforward as I think  :-\

Andrew
Title: Re: Grinding software upgrade is coming
Post by: wootz on October 23, 2019, 07:29:23 pm
Hi Vadim,

Could the angle issue simply be due to the reduction in the jig projection length during grinding, as illustrated in the schema diagram in your initial post? If it is would it not be better to recheck the projection after each grinding step in your sharpening procedure, and if necessary return to the initial projection length using the adjustable stop? Perhaps such a tweak is all that is needed to ensure the target edge angle is always maintained.

Or may be I've missed something and it is not as straightforward as I think  :-\

Andrew

I wish it were that simple.
What we've been doing for the last 2 weeks - grouped knives by blade thickness behind the edge: under 1mm, near 2mm and near 3mm, and sharpened each group from 10 to 20 degrees at 1-2 degree step, on two T8 and two T7 machines, in the standard position and edge-trailing using our Frontal Vertical Base.
The laser protractor numbers tell us that the ground angle we get depends on 4 factors: the angle, the thickness behind the edge, whether the blade is double-bevel or single-bevel, and whether the grinding is done edge-leading or edge-trailing.

Our formulas now factor in the difference between the double-bevel and single-bevel blade, and the blade thickness behind the edge. It is not the same as the thickness at the spine, so has nothing to do with modifying the knife jig to center the blades better. You can have a blade 5 mm thick at the spine but thin behind the edge. But of course, you still have to center the blade in the jig as practical.

The new computer algorithm in our software not only has formulas that factor in the blade thickness, but also follows the experimental numbers we've obtained for each edge angle from 10 to 20, ground edge-leading vs edge-trailing, to grind the correct target angle no matter what.
We've made a big change from a pure theoretical algorithm to the one fine-tuned by 100 of experimental sharpenings. This makes the match to the honing angle perfect. At the end of the day, all the man-hours we've put into this improvement are to better the deburring and sharpness.
Title: Re: Grinding software upgrade is coming
Post by: wootz on October 23, 2019, 08:05:37 pm
A word on home-made FVBs.
4 months ago we started CNC machining the FVB base, and have tolerances tight.
If your self-made FVB does not have the base of the same thickness as ours or legs in the wrong position, you will be getting less accurate results, and all the man-hours we've put into this software improvement will be wasted as you will not be getting better deburring and sharpness with it.
I'll be stopping making custom applets for home-made FVBs because of that, because formulas by themselves will never match the algorithm fine-tuned to our particular FVB make.
Title: Re: Grinding software upgrade is coming
Post by: van on October 23, 2019, 09:31:33 pm
Hi Vadim,

Could the angle issue simply be due to the reduction in the jig projection length during grinding, as illustrated in the schema diagram in your initial post? If it is would it not be better to recheck the projection after each grinding step in your sharpening procedure, and if necessary return to the initial projection length using the adjustable stop? Perhaps such a tweak is all that is needed to ensure the target edge angle is always maintained.

Or may be I've missed something and it is not as straightforward as I think  :-\

Andrew

I wish it were that simple.
What we've been doing for the last 2 weeks - grouped knives by blade thickness behind the edge: under 1mm, near 2mm and near 3mm, and sharpened each group from 10 to 20 degrees at 1-2 degree step, on two T8 and two T7 machines, in the standard position and edge-trailing using our Frontal Vertical Base.
The laser protractor numbers tell us that the ground angle we get depends on 4 factors: the angle, the thickness behind the edge, whether the blade is double-bevel or single-bevel, and whether the grinding is done edge-leading or edge-trailing.

Our formulas now factor in the difference between the double-bevel and single-bevel blade, and the blade thickness behind the edge. It is not the same as the thickness at the spine, so has nothing to do with modifying the knife jig to center the blades better. You can have a blade 5 mm thick at the spine but thin behind the edge. But of course, you still have to center the blade in the jig as practical.

The new computer algorithm in our software not only has formulas that factor in the blade thickness, but also follows the experimental numbers we've obtained for each edge angle from 10 to 20, ground edge-leading vs edge-trailing, to grind the correct target angle no matter what.
We've made a big change from a pure theoretical algorithm to the one fine-tuned by 100 of experimental sharpenings. This makes the match to the honing angle perfect. At the end of the day, all the man-hours we've put into this improvement are to better the deburring and sharpness.
Congratulations on your work and self-denial.
I think maybe some photos would make everything more understandable
with regard
Title: Re: Grinding software upgrade is coming
Post by: wootz on October 24, 2019, 03:21:48 am
Thank you for mentioning the source :)

Ton, I believe in credit where it is due.
Your name is in the Acknowledgements of my book

(http://knifegrinders.com.au/dropbox/Book_Cover.jpg)
Title: Re: Grinding software upgrade is coming
Post by: wootz on October 26, 2019, 12:51:13 pm
I have shaped several blanks into blades without observing differences between the desired and sharpened bevel angle provided that the projection length has not been shortened during blank sharpening.

I use my Excel script to calculate the distance between the USB and the wheel surface. My script works without approximations.

Jan

I did trial sharpening by Jan’s formula / JVH _TormekCalc.xlsx with a knife 2.5 mm thick at the spine - the results:

(http://knifegrinders.com.au/dropbox/testing_Jan.png)

If you have a laser protractor, you can see to yourself that neither Jan's formula nor _TormekCalc.xlsx by JVH grind to the exact angle, and the thicker the blade, the greater is deviation from the target.

While our updated Grinding Angle Setter and the FVB applet grind exact angle, as I’ve shown in the testing results.
Title: Re: Grinding software upgrade is coming
Post by: Jan on October 26, 2019, 02:47:17 pm
Wootz, exact estimation of bevel angle is not an easy task especially for hollow grinded blade. The angle at the tip and at the heel are different. We are interested in bevel angle at the tip.

Catra offers two categories of laser goniometers: hobby and commercial.
1)   Hobby laser goniometer “HOBBIGIONI” measures sharpened angle
to an accuracy of +/- 2 degrees
2)   Portable laser goniometer measures sharpened angle to an accuracy of +/- 1 degrees
3)   Laboratory laser goniometer measures sharpened angle to an accuracy of +/- 0.5 degrees

The commercial goniometers have focusable lasers, because without the knowledge of the laser beam diameter we can non make serious angle measurements, because we simply do not know how large segment of the edge we are measuring.

The statistical significance of your results is very low because the sharpened angle was estimated with too large error. 

Even the accuracy of lab laser goniometer ad3), which costs some 3000 Euro, is hardly sufficient to demonstrate the dependence of sharpened angle on the blade thickness behind the edge.

In 2016 I have built my homemade laser goniometer and I know in detail all the pitfalls that this method brings. The accuracy of my goniometer is between 0.5 and 1 degrees. The problem is not the accuracy of reading but the interpretation of the reflections from the edge. https://www.tormek.com/forum/index.php?topic=3104.0

Jan


Title: Re: Grinding software upgrade is coming
Post by: wootz on October 26, 2019, 11:40:13 pm
Jan, I knew you would be faulting the method because you are in denial of the fact that the blade thickness behind the edge must be factored into the calculation.

We've done a 100 of test sharpenings for last weeks to make our Grinding Angle Setter and the Frontal Vertical Base applets accurate. We do it for our customers, not for fun. Our updated software release is coming in 10-14 days. You then can get our updated applet, and see to yourself how well it works, not by your abstract estimation, but in actual sharpening.
Title: Re: Grinding software upgrade is coming
Post by: Jan on October 27, 2019, 11:50:50 am
Vadim, I truly deeply admire your commitment to do these laborious experiments.

You are correct, I still have not digest the fact the sharpened angle depends on the blade thickness behind the edge. For me it is a new, almost revolutionary, hypothesis and that is why I am reluctant to accept it without detailed clarification. I do not see this thickness as a variable in the new Ton formula F9.

Sorry for my pedantic approach. Some time ago I worked for UN on screening and verification procedures and since that time I know how carefully each new hypothesis has to be analysed.

Because I have all necessary hw and sw tools I am conservatively reviewing and validating new procedures and formulas posted on this forum. You know that some two years ago I analysed the original Ton’s formula for bevel angle and found that it is only approximate and can give slightly biased results. Last year Ton revised his approach, derived a new formula which is exact. I have validated also his new tables and found they are OK now.  I am happy about it, I see my mission in it.

Vadim, I wish you all the best with your sw upgrade. I am looking forward to see additional data supporting your new hypothesis.  :)

Jan
Title: Re: Grinding software upgrade is coming
Post by: TorbenDenmark on November 01, 2019, 02:45:43 pm
Hi Jan,

Some time ago I made my own excel sheet to calculate these things. My calculations are not based on trigonometry but on vectors. I believe that my method does not introduce any errors.

You mention a new formula that you believe is correct Jan. I would very much like to compare my numbers with that. I have been searching this forum for 'ton', 'booklet' and more but nothing has showed up. Is this formula available for me? If so, can you help me find it?

BR
Torben
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 01, 2019, 04:22:56 pm
Torben, you are welcome. The Ton Nillesen formula is of course available for you also. The original but updated Dutchman thread “Simple adjustment of the grinding angle” is here: https://www.tormek.com/forum/index.php?topic=1849

The correct formula F9 you will find in a booklet More math for the Tormek grinder A5 serial.pdf stored at dropbox.
https://www.dropbox.com/sh/zfzeuyyhors8oid/Yyq5S71LxR

Please let me know if you have some additional questions.

Jan
Title: Re: Grinding software upgrade is coming
Post by: Dutchman on November 02, 2019, 09:07:53 am

I have been searching this forum for 'ton', 'booklet' and more but nothing has showed up. Is this formula available for me? If so, can you help me find it?

See links in my 'Signature'  ;)
Title: Re: Grinding software upgrade is coming
Post by: jvh on November 02, 2019, 11:43:43 pm

I did trial sharpening by Jan’s formula / JVH _TormekCalc.xlsx with a knife 2.5 mm thick at the spine - the results:

(http://knifegrinders.com.au/dropbox/testing_Jan.png)

If you have a laser protractor, you can see to yourself that neither Jan's formula nor _TormekCalc.xlsx by JVH grind to the exact angle, and the thicker the blade, the greater is deviation from the target.

While our updated Grinding Angle Setter and the FVB applet grind exact angle, as I’ve shown in the testing results.

Hello,

With all respect to you work I have doubt about test procedure and result interpretation.

I have never noticed the dependency of the grinded angle and the thickness of the blade behind the edge. Math used in TormekCalc is precise and verified firstly in CAD simulations and then in real life. I have to say that I get the expected results every time I grind. It doesn't mean that small corrections aren't needed, but they are always caused by dimension changes or measurement errors.

The most common is the jig projection length shortening if you grind too much (under the axis). Wheel diameter change should be considered too in longer grinding.
Measurement errors also affect grinded angle (e.g. ±0,16 mm of the jig projection length changes angle by ±0,1%; ±0,14 mm of the vertical USB heigth changes angle by ±0,1%).

Next thing is laser goniometer accuracy (Catra Hobbigoni has accuracy ±2 °) and its scale division is very tight (low resolution). Interpretation of laser reflecting is another source of errors.

Last at not least your results in this trial sharpening (12° gave + error , 20 ° gave - error) don't make a sense. Result seems to me inconsistent and I cannot simulate/verify it.

Please do not misunderstand this post, it is not meant to be offensive. Just I didn't notice such problem and there aren't detailed information about testing procedure (used equipments, measuring accuracy for all parts etc.). Therefore I have a doubts and I see possible systematic errors. Of course I can be completely wrong, but I haven't found any convincing evidence yet.

jvh
Title: Re: Grinding software upgrade is coming
Post by: wootz on November 03, 2019, 08:25:49 am
Ton Nillesen from Netherlands gave us mathematical description of knife sharpening on Tormek using an abstract model of a thin single-bevel blade.
Jan did a little tweak to Ton's formula, but this does not change the fact that it still describes the abstract thin single-bevel blade.
The _TormekCalc.xlsx by Jan JVH on this forum uses Jan's tweak as well, and still calculates grinding angle as if the blade is single-bevel and thin.

How on earth can this be accurate for a double-bevel blade?! For a thick blade? And especially for a thick double-bevel blade?

Formulas are giving a systematic error that Ton Nillesen explains in his 2018 booklet on page 6; and as Ton has shown, the thicker the blade and the lower the grinding angle, the greater is the error.
Why the 2 Jans persist in denial of what the author of this mathematical model himself says?

I've revamped my computer algorithm to take into account the blade particulars, and now our applets grind correct angle on double-bevel, single-bevel, thick and thin knives.

Grinding Angle Setter for Tormek
Released for Windows, MacBook, iPhones and iPads, and Android phones and tablets.
Details on our website.

Instructional video Software for Tormek >> (https://youtu.be/JjLrG-2iawY)

Frontal Vertical Base applet
Currently under review by Google Play and Apple Store. Will be released next week.

As soon as the FVB applet is released, I will email users of our software instructions on how to update both the Grinding Angle Setter and the FVB software free of charge.
... just in a few days...
Title: Re: Grinding software upgrade is coming
Post by: jvh on November 03, 2019, 01:46:19 pm
O.K., this is what's going on when grinding on any wheel - top of the edge has defined/counted angle (e.g. 20 °). Different angle is at the edge heel and it vary in dependency on thickness of the blade. This error is given by "roundness" of the wheel and can be eliminated by flat grinding on diamond wheels side only.

If you change grinding angle / heigth of the USB / jig protrusion length you will get better result at the edge heel but this will change the angle at the top of the edge accordingly.

All these errors exist but they are countable with pure math without any approximation and can be taken into account while grinding.

I still have doubt about your test procedure and result interpretation for some reasons. The main one is accuracy of used equipment. How you can see on Catra goniometer difference between angle 12 and 12,2°? The next big problem is height of the grinded edge. If you grind sharp angle or thick material you get very high grinded edge which makes wide reflection on laser goniometer. How do you evaluate such large reflection pattern with high accuracy? What is the accuracy of measurement of the jig protrusion length? What is the accuracy of measurement of the USB height? All these values (and many others) affect results and repeatability.

TormekCalc.xlsx (https://www.tormek.com/forum/index.php?topic=3919.0) doesn't use Jan's tweaks at all. All calculations are made in the axis of the knife, results are valid for all double bevel knifes (symmetrical) at the top of the edge. For single bevel knives is possible to make a correction of dimension JC by changing diameter of USB.
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 03, 2019, 04:28:08 pm
JVH, thank you very much for your drawing! :)  It nicely shows how the angle increases along the hollow. This angle increase is visible in measurement with laser goniometer as ellipsoidal widening of the dot reflected from the very edge.

Your drawing makes it clear that there is no assumption concerning edge thickness behind the edge in your approach. The same is true for my approach and also for the Ton formula F9.

Hopefully our reservations will help Vadim to reconsider his approach and mainly to explain the changes embedded in the sw upgrade more clearly. It is important for the sw acceptance by the grinder’s community. It would not be wise to keep the sw upgrade as black box with some ad hoc correction formulas of unknown provenience and accuracy. The reference to the page 6 of Ton booklet 2018 is fully insufficient.

Jan
Title: Re: Grinding software upgrade is coming
Post by: wootz on November 04, 2019, 03:56:26 am
Jans, simply start your Tormek, and set the grinding angle using your formula and _TormekCalc.xlsx.
Grind a single-bevel blade and a double-bevel and observe difference between the resulting edge angle and the calculated.
Then grind 2 double-bevel blades of differing thickness behind the edge and observe difference between the resulting edge angle and the calculated.
Then take the thicker blade and grind it at 20 degrees, and at 12 degrees, and observe how the deviation from the calculated angle increases.

Then you probably will reread Ton's explanation with more understanding.

What Ton does not mention, but I've found out, is that grinding with the wheel rotation goes differently to grinding into the wheel and requires additional mathematics. Therefore, you will see that the angle calculated for the Frontal Vertical Base by _TormekCalc.xlsx deviates from real edge angle even more.

I understand that accepting that may be frustrating to you both, but we have to adjust maths to the real world, the vice versa doesn't work.

Title: Re: Grinding software upgrade is coming
Post by: Jan on November 04, 2019, 09:52:57 am
Vadim, in real life I am sharpening double-bevel, medium quality kitchen knives, which usually have the thickness behind the edge 0.4 to 0.5 mm. For those knifes I have never observed deviations of the actually grind angle and the desired angle. The accuracy of my angle measurements is cca 0.5 degrees. 

When the blade thickness behind the edge is larger than some 0.75 mm then the knife usually does not perform well, despite small BESS score, and is an adept for blade thinning.

For routine USB set up (over 80% of my cases) I use my double ended kenjig for projection length of 139 mm and bevel angle 15 degrees. New diamond wheels with fixed diameter made this even simpler.
 
Jan
Title: Re: Grinding software upgrade is coming
Post by: Dutchman on November 04, 2019, 11:04:31 am
… grinding with the wheel rotation goes differently to grinding into the wheel and requires additional mathematics.

Can you explain that?
Title: Re: Grinding software upgrade is coming
Post by: jvh on November 04, 2019, 07:24:36 pm
Grind a single-bevel blade and a double-bevel and observe difference between the resulting edge angle and the calculated.
Then grind 2 double-bevel blades of differing thickness behind the edge and observe difference between the resulting edge angle and the calculated.
Then take the thicker blade and grind it at 20 degrees, and at 12 degrees, and observe how the deviation from the calculated angle increases.

TormekCalc (https://www.tormek.com/forum/index.php?topic=3919.0TormekCalc.xlsx) calculations are made in the axis of the jig and the knife, so results are valid for all symmetrical double bevel knifes with defined angle at the top of the edge. Error given by material thickness is suppressed there completely.

For single bevel knives is a correction necessary to get “right” axis of the jig. For this you can change diameter of USB or jig diameter value and “virtually” move the jig axis to the right place. Then you get exact results for single bevel knifes with defined angle at the top of the edge. Error given by material thickness is suppressed by the jig axis movement.

What is still present is error given by "roundness" of the wheel – see picture Edges.jpg – which caused that angle increases along the hollow. As you can see, the error is bigger with thicker material.

The essential thing is that you cannot eliminate* this error when grinding on rounded wheel. The only thing you can do is shift desired grinding angle closer to the edge heel. Then you get the desired angle at the edge heel but angle at the top of the edge will be smaller accordingly. If you shift the desired angle to the middle of grinded edge then you get smaller angle at the top of the edge and higher at the edge heel.

In view of the above, it is necessary to ask: Which point on the edge is the right one for the defined angle? Top? Middle? Heel? Something between?
It’s no problem to do it in TormekCalc – just change the jig projection length and you will get desired angle at the point where you want. Small corrections are sometimes needed while grinding because of change of the jig projection length, or measurement errors. It's really not dark magic or rocket science.


What Ton does not mention, but I've found out, is that grinding with the wheel rotation goes differently to grinding into the wheel and requires additional mathematics. Therefore, you will see that the angle calculated for the Frontal Vertical Base by _TormekCalc.xlsx deviates from real edge angle even more.

Sorry, without detailed explanation this doesn’t make a sense.

I don’t have any problem with grinded angles while using my FVB (regardless of direction of rotation). It should be noted here that all constants in TormekCalc have been set for my T-8 and FVB and may differ in other devices.


I understand that accepting that may be frustrating to you both, but we have to adjust maths to the real world, the vice versa doesn't work.

It’s not about frustration, it’s about precise inputs and corresponding outputs.
I made a robust testing on TormekCalc and I didn't find any problem with calculations. Here I write about some limitations and explain why it is so. TormekCalc is free and everyone can test it and check its outputs. I have no evidence that there is something wrong except your claim, which is not specifically substantiated, so I try to make it right.

I have indicated that I have doubts about the accuracy of your measurements, which affect the grinded angle and the subsequent interpretation of the results.
There is why:
1. Jig projection length  (video) (https://youtu.be/ZCKXeXTWl0o?t=143): Minimal supposed measuring/reading error ±0,25 mm
2. USB height  (video) (https://youtu.be/ZCKXeXTWl0o?t=232): Minimal supposed measuring/reading error ±0,1 mm
3. Wheel diameter  (video) (https://youtu.be/ZCKXeXTWl0o?t=54): Minimal supposed measuring/reading error ±0,1 mm

All these minimal errors together (in the worst scenario) will change the desired angle by ca ±0,25° at the exact jig projection length. Errors caused by FVB constants and by hand grinding aren’t included.

4. CATRA Hobbigoni protractor  (video) (https://youtu.be/rv2ulY6Less?t=53)
Scale division is poor, supposed reading error can be ±0,5°, big reflection pattern can be other source of errors. Declared accuracy by Catra “measures the sharpened angles to an accuracy of ±2°”.

Therefore I am skeptical of the reported results which seems to me inconsistent and I cannot simulate or verify them.


*) Actually it’s possible with flat grinding on diamond wheels or much more difficult way by changes of jig projection length while grinding.
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 04, 2019, 09:53:02 pm
JVH, I again agree with your arguments.


In view of the above, it is necessary to ask: Which point on the edge is the right one for the defined angle? Top? Middle? Heel? Something between?

The bevel angle is traditionally defined at the tip of the edge.


Jan
Title: Re: Grinding software upgrade is coming
Post by: wootz on November 04, 2019, 10:22:32 pm
At my workshop we sharpened 3 types of blades, under 1mm behind the edge, 2mm and 3mm thick behind the edge,
from 10 to 20 degrees per side, at 1 degree step, registering the actual edge angle vs calculated.

We repeated this grinding into the edge, and grinding with the edge using our Frontal Vertical Base.

This way we collected a set of experimental data.
Looking at these data I saw regularities that I expressed mathematically and included into our computer algorithm.

We then made another round of the above 100 sharpening sessions to confirm the new algorithm on 2 Tormek-8 and 2 Tormek-7 machines, as detailed in the Software Testing on our website http://knifegrinders.com.au/software_testing.htm (http://knifegrinders.com.au/software_testing.htm)

Our computer algorithm is the most accurate and the best tested.
This way we've improved matching of the ground angle to the honing angle, and knives sharpened using our updated software and Frontal Vertical Base are sharper than ever. Everyone can now get hair-splitting edge on his Tormek machine.

Jans, you better put aside your pencil, switch off your computer and switch on your Tormek.

Another good news: last week Tormek agreed to supplying us directly with the XB-100 part for our Frontal Vertical Base. The first boxes arrive to Australia in 2 weeks, and we won't have interruptions in production as we used to when we sourcing this part through retailers.
We are also the very first in Australia to get Tormek Extended Universal Support US-430, to supplement our Frontal Vertical Base but not sell individually.
Title: Re: Grinding software upgrade is coming
Post by: jvh on November 04, 2019, 11:45:57 pm
We then made another round of the above 100 sharpening sessions to confirm the new algorithm on 2 Tormek-8 and 2 Tormek-7 machines, as detailed in the Software Testing on our website http://knifegrinders.com.au/software_testing.htm (http://knifegrinders.com.au/software_testing.htm)

Our computer algorithm is the most accurate and the best tested.

Sorry, with all respect to you I have to say that it’s just your statement without any evidence. Your test results looks like from ideal world, at least you should quantify the overall error (systematic + random) that occurs during your measuring and grinding. Otherwise your results looks suspicious.

I cannot verify your testing procedure but I saw in your videos (in production run!) some problematic parts with length and angle measurement which I pointed in my previous post.

In my opinion, these errors and used equipment do not allow you to work with the accuracy you declare.

That's all, have a nice day.

jvh
Title: Re: Grinding software upgrade is coming
Post by: Dutchman on November 05, 2019, 09:38:18 am

This way we collected a set of experimental data.
Looking at these data I saw regularities that I expressed mathematically and included into our computer algorithm.

So you adjusted your formulas to fit the experimental data, but without knowledge of the cause?
I have no problem with that, except that it is unsatisfactory.
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 05, 2019, 12:42:05 pm
I am very sorry to say, that the discussion reveals that the very laborious experiment was not prepared correctly. Design of experiments is extremely important because only correctly designed experiments can advance knowledge in natural sciences and engineering.

Offensive communication cannot establish validity and reliability of results or reduce the measurement errors.

Jan
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 05, 2019, 05:12:26 pm

Jans, you better put aside your pencil, switch off your computer and switch on your Tormek.


Vadim, my recommendation is you switch off all your Tormek machines, take your pencil, switch on your computer and rethink the design of your experiments. Otherwise it can easily happen that all your toil be in vain. That would be a great pity.

The nice CAD drawing prepared by JVH is an excellent starting point for a constructive discussion. I was dreaming about such a drawing for a long time, but my light CAD sw was not able to depict the strongly zoomed geometry of the edge and wheel accurately. Thanks JVH my dream has come true.  :)

Jan
Title: Re: Grinding software upgrade is coming
Post by: Ken S on November 05, 2019, 06:41:25 pm
As forum moderator, I am getting concerned with this topic. You are all valued members of this forum. You have contributed much and I would not want to lose any of you. Please back away from this topic and let things cool down.

Ken
Title: Re: Grinding software upgrade is coming
Post by: Dutchman on November 06, 2019, 09:42:57 am
Wootz
Regarding the following statement, I can point out two reasons why there is a difference.
Quote from: wootz on November 04, 2019, 03:56:26 am
=> What Ton does not mention, but I've found out, is that grinding with the wheel rotation goes differently to grinding into the wheel

• The mounting of the USB is different in both cases. Either in the FVB or in the original position on the other side.
• You adjust the position of the USB relative to the bottom not to the center of the stone.
With this setting, the distance from the USB to the center of the stone should be the same in both cases to obtain the same grinding angle.
Your experiments however show that this is not correct and you have adjusted the "math" accordingly.
I recommend that you take a critical look at the position of the FVB, as the deviation must come from there.

However, a good method to set the USB gives the "KenJig".
There is no better way.  8)
Title: Re: Grinding software upgrade is coming
Post by: jvh on November 06, 2019, 08:13:24 pm
However, a good method to set the USB gives the "KenJig".
There is no better way.  8)

Excellent advice for verification!  :)

I would like to add that this "KenJig" dimension ("T" in my drawing) stays the same for all types of universal supports (on the same wheel for the same grinding angle and jig projection length).

jvh
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 06, 2019, 09:55:37 pm
JVH, thanks for perfectly documented calculation of the kenjig length T. The simple concept works for all Tormek machines! You do not need to know all the constants of different Tormek models. I have checked your length T = 83.19 mm and can confirm that it is correct and identical with my calculations for the same input parameters.
 
The same distance you will get from the new Dutchman tables also. (77.19 + 6.00 = 83.19 mm)

I agree with Dutchman. Kenjig is for me king of jigs. It is probably the fastest USB setting.  :)

Jan

Title: Re: Grinding software upgrade is coming
Post by: Ken S on November 07, 2019, 12:43:53 am
The kenjig is a very simple device, easily made of cardboard or plywood in only a few minutes in a home shop. Its magic is derived from very solid math. I no not understand the math beyond a basic level. I am grateful we have forum members like you guys with a solid mastery of our math.

I have seen amazing innovation from the forum. I am convinced we still have much more to develop. I look forward to innovative cooperative thinking from all of you.

Ken
Title: Re: Grinding software upgrade is coming
Post by: Morne1312 on November 07, 2019, 09:21:26 am
Where can one get more info regarding the Kenjig or how it works (set up, working etc?)
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 07, 2019, 09:58:42 am
The original description of kenjig concept’s you can find e.g. here:
http://sharpeninghandbook.info/Images/Tool-Jig-KenJig.pdf

About my modification to double-ended kenjig you can read e.g. here:
https://www.tormek.com/forum/index.php?topic=2654.0

Jan
Title: Re: Grinding software upgrade is coming
Post by: Ken S on November 07, 2019, 12:53:23 pm
Morne,

Be sure to pay close attention to the very informative photo Jan has included showing his double ended jig (what I call the "Janjig").  Jan's jig incorporates the very useful function of determining the Distance to the leather honing wheel (220 mm diameter). Jan has wisely decided to limit his jig to one bevel angle (15°). Having the jig for only one angle lessens the possibility of error. For angles other than 15°, the Protraction can be kept at 139 mm. Only a separate Janjig would be necessary. I would paint the second Janjig a different color to keep things simple.

The kenjig concept is designed to be "one size fits most" rather than "one size fits all". I designed it for three groups:
1) New users to simplify knife set up.
2) Infrequent users who need a simple set up with fewer skills to remember.
3) Farmers market sharpeners who need a very time efficient set up procedure to sharpen many knives quickly.

The applet and other programs are clearly preferred for high end sharpening, where the customer's original bevel or desired angle must be matched. In these cases, time involved is not as critical. My knife sharpening is my home knives. I standardized at 15°, although, following the new research, I am leaning toward converting to 12°. That will mean a few minutes and a bit more material to make up a new kenjig and a Janjig. I also keep the applet "at the ready" for higher tech work.

Ken
Title: Re: Grinding software upgrade is coming
Post by: john.jcb on November 07, 2019, 02:58:44 pm
Ken, have you also made allowances on your jig for setting an alternative honing angle on knives as detailed in Wootz's book on deburring?
Title: Re: Grinding software upgrade is coming
Post by: Ken S on November 07, 2019, 07:10:44 pm
Good question, John.

No, the kenjig predates Wootz' deburring book. You make a good point; I should update the kenjig. I would leave the Projection at 139mm and make special kenjigs (or Janjigs) for the Distances for the deburring stages.

Keep on thinking.

Ken
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on November 07, 2019, 07:20:50 pm
NEED FOR UPGRADE
In its current form, our software sets an accurate grinding angle for resharpening a knife with established bevels at the existing edge angle.
E.g. you resharpen a 15 degrees per side (dps) knife to the same 15 dps.

However, when grinding new bevels, sharpening a grossly dull knife or a knife blank gives an edge angle differing from the calculated target by 0.5-1.5 degree. The thicker is the blade behind the edge, and the lower is the new edge angle, the greater is the difference.
....

STATUS
I've coded the computer algorithm and currently testing in sharpening blades of varying thickness.
The calculations are along the lines of the explanation given by Ton Nillesen in 2018 on the page 6 of his additional booklet that can be downloaded from our website http://knifegrinders.com.au/Manuals/Grinding_Angle_Adjustment_Booklet_2018.pdf
....

After wootz posted this topic, I took another look at the section in Ton's (Dutchman) book on thickness...

(https://forum.tormek.com/index.php?action=dlattach;topic=4089.0;attach=3873)

... and quite frankly, I don't understand it.  (So, by default, I'm not saying wootz is right or wrong... I need clarification of the section).

Ton states that if you start grinding a thick blade, you're measuring to "Kb", but as you grind you end up out to "Ke".  This, to me, is not the case.  If I put a knife or wood like he did, in a clamp,...

(https://forum.tormek.com/index.php?action=dlattach;topic=4089.0;attach=3875)

 and measure the projection distance, I am measuring the total projection distance (Ke).  I'm never measuring to "Kb".  So, the calculator/formula automatically is set for the angle I want to end up at.  While it is obvious that at the start of the grind, the angle of the knife/wood in relation to the stone is different, at the end, I'm getting the angle the calculator provided.  That's the way I see it anyway.  (I actually did it to see if I was missing something).

Another part that has been left out of this conversation is the quote on p. 7....  "Furthermore this error is not present or negligible with sharpened blades".  Wootz even states above that his previous version "sets an accurate grinding angle for resharpening a knife with established bevels at the existing edge angle."  So, if I put in a thick blade, and wanted to set a new bevel, and use the new formula adjusting for thickness, I end up with a different USB height, than if I had the same blade and just wanted to sharpen at the current angle.  Isn't that a contradiction?

The only way you'd see a difference, is, (as someone else said), you start with a blade sharpened at a lower angle, that you want to put a higher angle bevel on.  This would grind right at the edge, and reduce the projection distance.  But, from what I can tell, the formula Ton provides, does not address this.  You could take off as little or as much metal you want, since each pass is right at the edge of the bevel.

In reading the section before, on "Comparison with the "Anglemaster", I'm led to believe that the "thickness error" is relative to the section on adjusting for thickness... i.e. if you want to compare the formula with the Anglemaster, you need to account for the thickness of whatever you're measuring.  (But that is my guess).

My opinion, based on my testing, is that the updated formula Ton provides on p.10, produces the desired angle at the end, with no need to adjust for thickness.  I don't understand what Ton's formula regarding thickness accomplishes.  SO, if I'm missing something, in this or in Ton's section, feel free to tell me. What exactly is Ton describing here?  ???

Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on November 07, 2019, 07:27:20 pm
Where can one get more info regarding the Kenjig or how it works (set up, working etc?)

Ken, have you also made allowances on your jig for setting an alternative honing angle on knives as detailed in Wootz's book on deburring?

Good question, John.

No, the kenjig predates Wootz' deburring book. You make a good point; I should update the kenjig. I would leave the Projection at 139mm and make special kenjigs (or Janjigs) for the Distances for the deburring stages.

Keep on thinking.

Ken

Well, since I'm here....

You don't need to make a Kenjig.  Get a caliper with a lock...

(https://forum.tormek.com/index.php?action=dlattach;topic=4089.0;attach=3877)

... or any measuring device similar to this...

(https://forum.tormek.com/index.php?action=dlattach;topic=4089.0;attach=3879)

... and you have "Kenjig", that you can "lock" to a particular distance, but also adjust as needed when things change.  ;)
Title: Re: Grinding software upgrade is coming
Post by: john.jcb on November 07, 2019, 08:42:19 pm
I actually have not made a jig but use calipers for my measurements. I do try and use a standard distance between the knife jig and blade edge.
Title: Re: Grinding software upgrade is coming
Post by: Ken S on November 07, 2019, 09:32:05 pm
The real secret of kenjig theory is standardization, not the tool itself. Of course, calipers and combination squares are adjustable, however, one can make a lifetime supply of kenjigs for a fraction of the cost of either adjustable tool. Also, the reading of a kenjig remains constant, with no need for constant remeasuring.

Ken
Title: Re: Grinding software upgrade is coming
Post by: jvh on November 08, 2019, 10:08:06 am
... and measure the projection distance, I am measuring the total projection distance (Ke).  I'm never measuring to "Kb".  So, the calculator/formula automatically is set for the angle I want to end up at.  While it is obvious that at the start of the grind, the angle of the knife/wood in relation to the stone is different, at the end, I'm getting the angle the calculator provided.  That's the way I see it anyway.  (I actually did it to see if I was missing something).

I explained this partially in my previous post (Reply #33 on: November 04, 2019, 07:24:36 pm).

We can say that that total projection distance X is always right. The dimension starts at the edge tip and this is also the first point of our axis.

If you have symmetrical double bevel knife and you center it well in the jig SVM-45 then the second point of axis lays in the axis of the jig and goes through point J.

Now it depends on used math because you can suppress this "thickness error" from the beginning with the correct calculation.

TormekCalc  (https://www.tormek.com/forum/index.php?topic=3919.0)calculations are made in the axis of the knife (point at edge tip) and the jig (point J), so results are valid for all symmetrical double bevel knives with defined angle at the edge tip. Error given by material thickness is suppressed there completely.

For single bevel knives or non-symmetric bevel knives is a correction necessary to get the “right” axis.
 
1. You can put some distance pad to the jig clamp to get "virtual symmetrical" edge - then the edge tip will shift to the axis of the jig.
2. In TormekCalc you can change diameter of USB or jig diameter value and “virtually” move the jig axis to the right place by change the JC dimension. Then you get exact results for single bevel or non-symmetric knives. Error given by material thickness is suppressed by the jig axis shift.
3. You can change USB height too but there isn't exact calculation for this at the moment.

jvh
Title: Re: Grinding software upgrade is coming
Post by: Dutchman on November 08, 2019, 12:14:00 pm

I don't understand what Ton's formula regarding thickness accomplishes.  SO, if I'm missing something, in this or in Ton's section, feel free to tell me. What exactly is Ton describing here?  ???
At your service  ;D
I have corrected text, Figure 6 and the table in "More math for the Tormek grinder" in the paragraph "Understanding why thickness matters"
The documents (See link in my signature) have been updated.
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on November 08, 2019, 02:43:31 pm

We can say that that total projection distance X is always right. The dimension starts at the edge tip and this is also the first point of our axis.

If you have symmetrical double bevel knife and you center it well in the jig SVM-45 then the second point of axis lays in the axis of the jig and goes through point J.

Now it depends on used math because you can suppress this "thickness error" from the beginning with the correct calculation.

TormekCalc  (https://www.tormek.com/forum/index.php?topic=3919.0)calculations are made in the axis of the knife (point at edge tip) and the jig (point J), so results are valid for all symmetrical double bevel knives with defined angle at the edge tip. Error given by material thickness is suppressed there completely.
.....

jvh

Thanks for the reply.  I agree with this.


At your service  ;D
I have corrected text, Figure 6 and the table in "More math for the Tormek grinder" in the paragraph "Understanding why thickness matters"
The documents (See link in my signature) have been updated.

Thanks for the reply and "corrected text".  I do have one more question though.  On the next page, you make the statement..

Quote
It will be clear that these considerations are related to single sided grinding. For double sided grinding the values Ke and tb will increase with 50% for grinding the first edge. Furthermore this error is not present or negligible with sharpened blades

In my view, this should say something like... For double sided grinding the values Ke and tb will increase with 50% for grinding the first edge, if you grind to the opposite side of the blade on the first edge.[/b] (Or something to that effect).

In other words, if I have a blunt blade, and grind one side to a burr, then flip it over and do the same, there will be a bit of an error (and also a reduced Projection Distance).  But, if I have a blunt blade, and grind each side a bit at a time, until I reach the center, then there is a negligible error.  (I know this is an ideal condition, and some of this is just wording, but I think it might clear up some of the issue).

...................................
Which perhaps comes back to what wootz is trying to do/say/correct for... if you have a blunt blade, and grind one side to a burr, then flip and repeat, there will be a bit of an error or difference, that needs to be adjusted for.  My questions to wootz would be, did you also update the formula (which I think is more accurate, regardless of thickness).  I would also ask, why, once a blade is sharpened, does your calculator still require a thickness entry, if the error/difference is no longer there?

I think we're all on the same page, or close anyway... it may just depend on how the blunt blade is actually ground?

Title: Re: Grinding software upgrade is coming
Post by: smurfs on November 08, 2019, 03:11:48 pm
Dutchman, please would you confirm if I am correct in thinking that the objective of the formula adjustment is to shift the tangent from the bevel edge to the blade center line so that the target angle occurs at the mid-point of the hollow grind, not at the edge?

If so (and if I'm not mistaken) the tangent at the blade mid-point runs parallel to the chord so I guess what your formula is effectively doing is calculating the angle of the chord, not the edge angle. Could this be the source of much of the confusion evident in this thread, or am I muddying the waters further? :)
Title: Re: Grinding software upgrade is coming
Post by: Dutchman on November 08, 2019, 03:25:56 pm

calculating the angle of the chord, not the edge angle. Could this be the source of much of the confusion evident in this thread, or am I muddying the waters further? :)
You are right AND "muddying the waters further" :) 8)
Title: Re: Grinding software upgrade is coming
Post by: smurfs on November 08, 2019, 04:30:58 pm

calculating the angle of the chord, not the edge angle. Could this be the source of much of the confusion evident in this thread, or am I muddying the waters further? :)
You are right AND "muddying the waters further" :) 8)
Or may be not...
So the enhancements that wootz has made to his software is in effect calculating the chord angle using the target grind angle, which means the angle at the edge is more acute. That being the case the finer edge angle goes some way to explaining how wootz is achieving lower BESS scores with the software tweaks, improvements I might add are probably at the expense of edge retention.
...more muddy water? :)
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 08, 2019, 05:27:16 pm
In the new thread started today by JVH it is discussed in details with additional drawings. https://www.tormek.com/forum/index.php?topic=4110.0

I have attached the simple prof. Verhoeven formula relating the bevel (tangent) angle and the chord angle.

Jan
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on November 08, 2019, 05:29:51 pm
Or may be not...
So the enhancements that wootz has made to his software is in effect calculating the chord angle using the target grind angle, which means the angle at the edge is more acute. That being the case the finer edge angle goes some way to explaining how wootz is achieving lower BESS scores with the software tweaks, improvements I might add are probably at the expense of edge retention.
...more muddy water? :)

That's probably reading too much into it... at least I don't think it would be all that significant.

FWIW... I purchased wootz updated app, and ran some numbers, comparing it to both Dutchman's old and new formulas.  Here's a quick sample...

(https://forum.tormek.com/index.php?action=dlattach;topic=4089.0;attach=3900)

... if anything, things are probably starting to line up a bit better between calculators?  (I didn't double check it, and it would be interesting to see, for example a comparison of angles setting the USB with wootz app, then "reversing" it to see the angle in Dutchman's New Formula, but in most cases, doesn't seem to be that much).

Also, jvh... you brought this up earlier...

...
Last at not least your results in this trial sharpening (12° gave + error , 20 ° gave - error) don't make a sense. Result seems to me inconsistent and I cannot simulate/verify it.
...
jvh

... I noticed the same thing when I was doing testing before, I think between the old and new formulas.  I remember doing most of my testing at 15°, because it seemed "neutral".  I don't know why (i'll leave that for you smarter people), but I don't think it has anything to do with wootz's revision.
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on November 08, 2019, 05:51:09 pm
In the new thread started today by JVH it is discussed in details with additional drawings. https://www.tormek.com/forum/index.php?topic=4110.0

I have attached the simple prof. Verhoeven formula relating the bevel (tangent) angle and the chord angle.

Jan

But, (mostly for clarification), the calculator sets the angle based on the tangent at the very edge, right? (So, doesn't it account for this? Basically what jvh said earlier...)
Title: Re: Grinding software upgrade is coming
Post by: Josu V on November 08, 2019, 06:08:59 pm
Hello everyone.
The following comment is not to solve the "problem" about the thread of discussion, but I think all points of view are interesting.

I have no advanced mathematical knowledge and it is impossible for me to offer a qualified point of view, but I have the other part of the equation: the practice.

I received the actualizated app of Wootz and I have used it in (about) 40 knives including the day of today.
This knives been between 0,4mm to 2,5mm thicknes behind the edge.
Absolutly all the knives finished in target angle. The comprobation of the angle was with Catra Laser Protractor.
I know the Catra have a tolerance, but the ressults have been clarifiers in my opinion.

Nothing more. I would like to have enough level in order to clarify this problem, but only can offer this.

Regards
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 08, 2019, 06:11:36 pm
Ken, have you also made allowances on your jig for setting an alternative honing angle on knives as detailed in Wootz's book on deburring?

Good question, John. Yes, the kenjig concept allows for setting an alternative honing angle on knives.

First alternative which was mentioned by Ken is making honing kenjigs with distances for different deburring stages.

Second alternative is even simpler. When the kenjig for projection length of 139 mm sets the USB for honing 15 degree bevel angle then one full revolution of the knife jig stop’s changes this angle by some 1.6 degrees. If you e.g. intend to hone this blade at edge angle of 15.4 degrees you simply rotate the jig stop by 90 degrees.

This example is valid for T7 and T8.

Jan
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 08, 2019, 06:19:59 pm
In the new thread started today by JVH it is discussed in details with additional drawings. https://www.tormek.com/forum/index.php?topic=4110.0

I have attached the simple prof. Verhoeven formula relating the bevel (tangent) angle and the chord angle.

Jan

But, (mostly for clarification), the calculator sets the angle based on the tangent at the very edge, right? (So, doesn't it account for this? Basically what jvh said earlier...)

Yes, CBWX, you are right!

Jan
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on November 08, 2019, 08:29:26 pm
In the new thread started today by JVH it is discussed in details with additional drawings. https://www.tormek.com/forum/index.php?topic=4110.0

I have attached the simple prof. Verhoeven formula relating the bevel (tangent) angle and the chord angle.

Jan

But, (mostly for clarification), the calculator sets the angle based on the tangent at the very edge, right? (So, doesn't it account for this? Basically what jvh said earlier...)

Yes, CBWX, you are right!

Jan

Thanks!



Hello everyone.
The following comment is not to solve the "problem" about the thread of discussion, but I think all points of view are interesting.

I have no advanced mathematical knowledge and it is impossible for me to offer a qualified point of view, but I have the other part of the equation: the practice.

I received the actualizated app of Wootz and I have used it in (about) 40 knives including the day of today.
This knives been between 0,4mm to 2,5mm thicknes behind the edge.
Absolutly all the knives finished in target angle. The comprobation of the angle was with Catra Laser Protractor.
I know the Catra have a tolerance, but the ressults have been clarifiers in my opinion.

Nothing more. I would like to have enough level in order to clarify this problem, but only can offer this.

Regards

I think we're all pretty close... consistency can be just as (if not more important) than accuracy, so no matter what one decides to use, stick with it!

Sometimes I think we're splitting hairs, in the hopes of splitting hairs.  ;)
Title: Re: Grinding software upgrade is coming
Post by: wootz on November 08, 2019, 09:01:46 pm
Instructions on our software update have been emailed.
If we missed someone, it means we do not have your email on records - please email us a proof of purchase of the original applet, and we will email you a promo code to install the updated applet free of charge.

Feedback from Spain:
(http://knifegrinders.com.au/dropbox/applet_feedback.png)
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 08, 2019, 09:28:34 pm

FWIW... I purchased wootz updated app, and ran some numbers, comparing it to both Dutchman's old and new formulas.  Here's a quick sample...


CB, thanks for spending money for purchasing the updated app. It is of key importance for our discussion here. The differences are large! Please if you find some time make similar comparison for the honing wheel also. Thanks in advance.

Jan
Title: Re: Grinding software upgrade is coming
Post by: jvh on November 08, 2019, 10:28:41 pm
Hello everyone.
The following comment is not to solve the "problem" about the thread of discussion, but I think all points of view are interesting.

I have no advanced mathematical knowledge and it is impossible for me to offer a qualified point of view, but I have the other part of the equation: the practice.

I received the actualizated app of Wootz and I have used it in (about) 40 knives including the day of today.
This knives been between 0,4mm to 2,5mm thicknes behind the edge.
Absolutly all the knives finished in target angle. The comprobation of the angle was with Catra Laser Protractor.
I know the Catra have a tolerance, but the ressults have been clarifiers in my opinion.

Nothing more. I would like to have enough level in order to clarify this problem, but only can offer this.

Regards


Hello,

thank you for your report. Can you give us more information to get a better overview?

Did you check angles also when you were using previous version of app and did you notice some difference between old and new results?

Which angle did you grind typically and what was overal range of angles which you grinded on last 40 knives?

Regards
jvh
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on November 08, 2019, 10:42:17 pm

FWIW... I purchased wootz updated app, and ran some numbers, comparing it to both Dutchman's old and new formulas.  Here's a quick sample...


CB, thanks for spending money for purchasing the updated app. It is of key importance for our discussion here. The differences are enormous! Please if you find some time make similar comparison for the honing wheel also. Thanks in advance.

Jan

If you mean the FVB app... I don't have the ability to test that.  (It requires his FVB).

I went ahead and did a comparison of the earlier chart... answering "what would the angle be in Dutchman's new formula, using the USB height set in wootz new app (the angles are in parenthesis)...

(https://forum.tormek.com/index.php?action=dlattach;topic=4089.0;attach=3902)

... IMO, (in this limited set), most differences aren't that big... the exception being the 2mm thickness at 10°.  (WD:250 PD:140).  That one is 2° difference.  Even comparing it to the "old formula" it's significant. (That should be large enough to show up in an actual test).  But for most knives, the difference is not that significant... everything else is less than 1°.  (This is all theory at this point on my end... no motor running).  (Hopefully, I did it right).  :o

I'm thinking most of the "checks" aren't accurate enough to validate one way or the other...  but either way, it's better than the AngleMaster!  ;D
Title: Re: Grinding software upgrade is coming
Post by: Jan on November 09, 2019, 11:28:12 am
CB, thanks for your analysis which shows that the maximum error for the limited input data set is some 2⁰ while the majority is probably smaller than 1⁰.

You are a benevolent judge. This benevolence may be understood with the explanation that changing bevel angle by 1⁰ will not dramatically change the cutting performance of the blade.

The major concern is that +/-1⁰ error in bevel angle and +/-1⁰ error in honing angle may be fatal for edge deburring. Having those errors it is not possible to reliable setup an alternative honing angle on knives as detailed in the booklet on deburring. For this reason I have asked you to kindly include also the honing wheel diameter in your table.

Jan
Title: Re: Grinding software upgrade is coming
Post by: Josu V on November 09, 2019, 04:47:31 pm

Hello,

thank you for your report. Can you give us more information to get a better overview?

Did you check angles also when you were using previous version of app and did you notice some difference between old and new results?

Which angle did you grind typically and what was overal range of angles which you grinded on last 40 knives?

Regards
jvh

Yes.
Exactly was 38 knives.
10 knives was sharpened at 17º  (butcher knives)
25 knives was sharpened at 15º (kitchen knives)
3 Knives at 20º (two folden knives and one knife. All for Hunting
All in DPS.

With the old app, I did not verified all knives, but sometimes I finded an error of +1º at maximum. I have not exact notes of the final angle of all of knives, but always was higher angle than target.
Sharpened with SG-250 (actually 227mm of diameter), DF-250 and DE-250

This is all the information that I can offer.

Regards
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on November 09, 2019, 06:38:50 pm
CB, thanks for your analysis which shows that the maximum error for the limited input data set is some 2⁰ while the majority is probably smaller than 1⁰.

You are a benevolent judge. This benevolence may be understood with the explanation that changing bevel angle by 1⁰ will not dramatically change the cutting performance of the blade.

The major concern is that +/-1⁰ error in bevel angle and +/-1⁰ error in honing angle may be fatal for edge deburring. Having those errors it is not possible to reliable setup an alternative honing angle on knives as detailed in the booklet on deburring. For this reason I have asked you to kindly include also the honing wheel diameter in your table.

Jan

Like I said, the honing setup is separate, I can't provide that info.

If the "error" is consistent, it would cancel out (or hopefully favor a higher angle in honing). ;)  (I've always said "consistency").

I mainly came here to get a better understanding of the section in Dutchman's book (that I'm now satisfied with).

Here's the way I see it, and why I published the chart.  For the most part, other than the 2mm thickness (which that thickness behind the edge would cause other issues anyway...), I don't see a glaring difference... and probably overall pretty consistent.  Most Tormek sharpeners aren't going to get caught up in the decimals... frankly "Sharpie accuracy" probably suffices.  I do think there may be some issues, or at least some questions with this approach, most have which already been presented, but wootz doesn't seem interested in working this out, so at this point, it's probably not worth it to belabor the issue.  My .02.  :)
Title: Re: Grinding software upgrade is coming
Post by: Dutchman on November 09, 2019, 07:13:01 pm

but either way, it's better than the AngleMaster!  ;D
Thank you for testing and verifying that.
But the most important thing about this method is that the setting is also much faster if you don't use that computer. :) ;) :D ;D
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on November 09, 2019, 09:23:27 pm
...
But the most important thing about this method is that the setting is also much faster if you don't use that computer. :) ;) :D ;D

It makes me look more smarter.   ;D
Title: Re: Grinding software upgrade is coming
Post by: Ken S on November 10, 2019, 03:32:04 pm
...
But the most important thing about this method is that the setting is also much faster if you don't use that computer. :) ;) :D ;D

It makes me look more smarter.   ;D

The ancestor of the kenjig used neither a computer, grinding tables nor math. I used my TTS-100 turning tool setter and, only for setting up the TTS-100, my Anglemaster. I used the two holes in the TTS-100 to set the Distance. I don't remember the exact Distance; it doesn't matter. What does matter is that it is constant and easily repeatable.

I set the Projection (for sharpening chisels) by placing the chisel in the square edge jig and adjusting the Projection with my Anglemaster until it matched the desired angle. I placed a blank piece of white labelmaker tape in one of the slots of the TTS-100 and used a Sharpie to scribe a line for the Projection. The last step was to note the degrees (“25°”).

The initial set up was a bit clumsy, however, every chisel afterward is set up quickly, consistently, and with no calculating, either with computer or grinding tables.

When Dutchman posted his booklet in 2014, I realized that his tables would be a hyper leap forward in applying standard settings to knives. Supported by his tables, I can use a humble kenjig made several years ago and get consistent settings very quickly.

Today, I also have the Knife Grinders applet in my arsenal of available tools. I use the applet differently than shown in the KG videos. I believe the videos show the correct way to learn how to use the applet. However, in my case, my knife sharpening is limited and simple. I am rethinking my 15° bevel angle. I may eventually change my standardized angle to 12°. Either way, it will be constant. My Projection will remain at 139 mm. My Distance will remain almost constant, varying only slightly with wheel wear, except for diamond and CBN wheels which remain constant. The diameter of my leather honing wheel remains constant. Using the applet allows me to incorporate my recently purchased FVB. However, the set up for the FVB for me, once established, will remain constant. I do not need a computer in my workshop.

Occasionally I do need to make changes. I needed to use Dutchman's tables to make a kenjig to sharpen my Chinese cleaver. I added another SVM-45 jig with paring knives set for 125mm Projection to eliminate the need for the small blade tool. This required using the tables and making another kenjig.

As I become more sophisticated with burr removal, I plan to use the applet more with initial set up.

Back to Dutchman's quote, I agree that not needing a computer for routine sharpening is definitely faster.

Must dash.

Ken
Title: Re: Grinding software upgrade is coming
Post by: wootz on November 16, 2019, 01:43:07 am
Tormek-4 owners, please bear with me - the testing is still in progress.

We do not use Tormek-4 in our sharpening workshop, but I've bought a T-4 for the purpose of the testing. Proper testing requires constant diameter of the grinding wheels; since we do not make 200mm CBN wheels I had to order them from WoodTurnersWonders USA, but they say they are on backorder from their factory, ETA 4 weeks.

I will have every grinding and honing regimen tested for T-4 as we've done for T-7 and T-8, and in 2 months the software for T-4 will become as reliable as it is now for T-7/8. For now the result may be playing in both the Grinding Angle Setter and the Frontal Vertical Base applet because of the pure theoretical extrapolation based on the T-4 constants.
T-4 is the last piece in our big revision that is still pending experimental verification... Well, if I can find a SuperGrind 2000 around, I will test it in real sharpening as well.
When ready, I will email the update to Tormek T-4 owners we have on our records. Appreciate your patience.
.
Title: Re: Grinding software upgrade is coming
Post by: Ken S on November 16, 2019, 02:32:13 am
Wootz,

On behalf of the millions of T4 owners who have been anticipating your applet, THANK YOU!

Ken
Title: Re: Grinding software upgrade is coming
Post by: Nitram on November 17, 2019, 12:03:35 pm
Hello Wootz,

Thank you very much for your efforts to test the software on the T-4, too.
No problem if it takes a while.

Cheers
Title: Re: Grinding software upgrade is coming
Post by: Roger M. on February 28, 2020, 09:35:30 pm
I don't see updates anywhere else on this forum (or any other or that matter), but was wondering if anybody has heard anything related to the updated information Wootz indicated he was working on for the benefit of T-4 owners?
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on February 28, 2020, 10:47:52 pm
I don't see updates anywhere else on this forum (or any other or that matter), but was wondering if anybody has heard anything related to the updated information Wootz indicated he was working on for the benefit of T-4 owners?

I haven't seen any updates to the app since he last posted.

If you're talking about the standard app, it appears pretty accurate to me.  (I use .5mm for thickness... it seems to be closest to answers I get with other calculators).

Do you have the FVB and software and have you tried it?  I tested it a while back, and it seemed to give results that were almost 5° low compared to both measuring directly to the wheel or comparing it with the AngleMaster (and a flat target).  I figured since KnifeGrinders was going to update the app, I'd wait and see what the results were (but forgot about it until you brought it up).

Didn't spend a lot of time on it... would be interesting to see what you're getting, if you (or anyone else) have the FVB setup.
Title: Re: Grinding software upgrade is coming
Post by: Scotty on March 17, 2020, 05:23:54 pm
I am new to the world of “really sharp” knives, but have been on the quest for years.
After reading Wootz’s book (learn something new each time), watching the videos, and scouring anything I could find, I believe I am on the right path.

Having said that , it may be kinda like golf: always trying but never attain the grail.
I have downloaded three of Knife Grinder’s apps (Grinding Angle Setter, Paper Wheel Angle Setter, and Front Vertical Base).
Problem I am having is the first two programs will not accept a “blade thickness behind the edge in mm” value of less than 1 (eg 0.7 etc.) and if I leave it blank, the program will not compute.
Issue with the FVB program will not process without the PIN code for the FVB.
Since they were not available on til recently, I had fabricated my own FVB ( after reading about some members of this forum doing so).
Just trying to do it correctly
Would appreciate any thoughts and/or advice
Title: Re: Grinding software upgrade is coming
Post by: Al on March 17, 2020, 06:22:42 pm
I am having problems with the 3 apps opening
Have just gotten a new laptop and can’t open any of them. I too think I need the activation pin from knife grinders. Have emailed them about this issue but haven’t heard anything in the last few weeks. Wootz must be run off his feet!
Very unusual as he is usually really prompt
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on March 17, 2020, 08:04:15 pm
I am new to the world of “really sharp” knives, but have been on the quest for years.
After reading Wootz’s book (learn something new each time), watching the videos, and scouring anything I could find, I believe I am on the right path.

Having said that , it may be kinda like golf: always trying but never attain the grail.
I have downloaded three of Knife Grinder’s apps (Grinding Angle Setter, Paper Wheel Angle Setter, and Front Vertical Base).
Problem I am having is the first two programs will not accept a “blade thickness behind the edge in mm” value of less than 1 (eg 0.7 etc.) and if I leave it blank, the program will not compute.
Issue with the FVB program will not process without the PIN code for the FVB.
Since they were not available on til recently, I had fabricated my own FVB ( after reading about some members of this forum doing so).
Just trying to do it correctly
Would appreciate any thoughts and/or advice

I can tell you that Wootz (KnifeGrinders) believes thickness matters, and will not allow a lower value.  I emailed him about that, and that is what he believes, so that is not an error, it is intentional.

Edit:  I should add, there is a bug depending on what version you use.  You can enter a value below 1 for thickness, but you have to enter it as 0.5  not just .5     You have to use the "0." and should be able to enter down to 0.2mm, depending on the other parameters.

If you fabricated your own FVB, unless you have the exact measurements and dimensions as the one KnifeGrinders makes, his computer program will not work with your setup.  (And, I don't think he will program one for your setup anymore).  (To get the PIN #, you have to purchase his FVB).

But there are other options! ;)  Click on my signature....  8) 
Title: Re: Grinding software upgrade is coming
Post by: Scotty on March 17, 2020, 09:12:16 pm
Well dang.
Thanks.
Tried all variations  of data that I can think of.
Reckon I will have to get his FVB - even though I was kinda proud of mine.
Appreciate the response.
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on March 17, 2020, 09:28:06 pm
Well dang.
Thanks.
Tried all variations  of data that I can think of.
Reckon I will have to get his FVB - even though I was kinda proud of mine.
Appreciate the response.

If you click on my signature link... there are several calculators available... any that measure directly to the wheel, will work with your FVB.
Title: Re: Grinding software upgrade is coming
Post by: Scotty on March 18, 2020, 03:33:38 am
Thanks, but cannot find the link.
Working off an IPad,  so I am limited on computer interface.
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on March 18, 2020, 04:07:21 am
Thanks, but cannot find the link.
Working off an IPad,  so I am limited on computer interface.

http://sharpeninghandbook.info/indexCalc.html
Title: Re: Grinding software upgrade is coming
Post by: chiamsi on March 30, 2020, 08:46:24 am
Hello,
I am new here and just ordered a t-4. I tried to purchase the Mac version on the App Store but it is not available in the German App Store.
Is there any other way to get the SW?

Thank you
Ernst
Title: Re: Grinding software upgrade is coming
Post by: Dutchman on March 30, 2020, 09:12:05 am

 I tried to purchase the Mac version on the App Store but it is not available in the German App Store.
Is there any other way to get the SW?
It is not in the app store.
Here it is: https://connect.calcapp.net/?app=qq0pg0#/ (https://connect.calcapp.net/?app=qq0pg0#/)
Title: Re: Grinding software upgrade is coming
Post by: Al on March 30, 2020, 11:51:35 am
Have heard from Wootz managed to get all my apps working a treat .things have been quite slow down here in NZ with Covid 19 putting our whole country in lock down for at least a month
Title: Re: Grinding software upgrade is coming
Post by: john.jcb on March 30, 2020, 04:37:51 pm
Have heard from Wootz managed to get all my apps working a treat .things have been quite slow down here in NZ with Covid 19 putting our whole country in lock down for at least a month

Al I hope all is well in NZ. It is quiet here in the US with almost everyone in their homes. I will probably go grocery shopping this week. The weather where I live has been awful with rain and some snow so it was not hard to remain indoors. The Sun is actually out today and maybe I will get out and do some yard work. I have a lot of pork ribs in the freezer aand plan on smoking them when it is a tad warmer.
Title: Re: Grinding software upgrade is coming
Post by: Roger M. on March 31, 2020, 04:32:07 am
For those using the KnifeGrinders software, Vadim just updated his software yesterday for the iPhone. So the Grinding Angle Setter app, and the FVB app are both available right now to update via the iPhone App Store.

He's also updated the Grinding Angle Setter app for the MacBook laptop, but he notes that today (March 30th) Apple has not yet uploaded the updated version, so he suggests you (actually "I") wait a day or two to make sure you're either purchasing, or updating to this most recent version.

Great news for users of Vadim's software.
Title: Re: Grinding software upgrade is coming
Post by: john.jcb on March 31, 2020, 03:26:50 pm
Thanks for the heads up Roger. I will update mine this morning.
Title: Re: Grinding software upgrade is coming
Post by: chiamsi on March 31, 2020, 08:40:22 pm
I bought the Grinding Angle Settings SW on the App Store for IOS.
Cant find the setting for the grinding wheel diameter and the blade thickness.
Is this correct?

Regards
Ernst
Title: Re: Grinding software upgrade is coming
Post by: john.jcb on April 01, 2020, 12:08:49 am
Both values should be available for entry.

I looked at mine and the values are there for entry.
Title: Re: Grinding software upgrade is coming
Post by: Roger M. on April 01, 2020, 02:35:57 am
I bought the Grinding Angle Settings SW on the App Store for IOS.
Cant find the setting for the grinding wheel diameter and the blade thickness.
Is this correct?

Regards
Ernst
Attach a screenshot. Your post doesn’t make a lot of sense in light of the app being one small window with a few fields to fill in.
Title: Re: Grinding software upgrade is coming
Post by: chiamsi on April 01, 2020, 11:21:25 am
looked at it again and indeed you guys are 100% right.
My mistake!
I thought the grinding wheel diameter is related to the Torweg-8 only

Ernst


Title: Re: Grinding software upgrade is coming
Post by: Roger M. on April 02, 2020, 07:07:07 am
Ahhh, yes ... I know exactly what you're talking about.
Even though it's a small window that contains the entire app, you do have to be clear that the radio buttons to select the model number have nothing to do with the text for the variables immediately to the right of those radio buttons.
There should probably be a vertical line separating the machine model selection buttons from the text describing the assorted fields that you enter the variables into ... it can be a bit confusing for a new user.
Title: Re: Grinding software upgrade is coming
Post by: wootz on April 03, 2020, 04:13:46 am
Tormek-4 owners, please bear with me - the testing is still in progress.

We do not use Tormek-4 in our sharpening workshop, but I've bought a T-4 for the purpose of the testing. Proper testing requires constant diameter of the grinding wheels; since we do not make 200mm CBN wheels I had to order them from WoodTurnersWonders USA, but they say they are on backorder from their factory, ETA 4 weeks.

I will have every grinding and honing regimen tested for T-4 as we've done for T-7 and T-8, and in 2 months the software for T-4 will become as reliable as it is now for T-7/8. For now the result may be playing in both the Grinding Angle Setter and the Frontal Vertical Base applet because of the pure theoretical extrapolation based on the T-4 constants.
T-4 is the last piece in our big revision that is still pending experimental verification... Well, if I can find a SuperGrind 2000 around, I will test it in real sharpening as well.
When ready, I will email the update to Tormek T-4 owners we have on our records. Appreciate your patience.

Tormek T-4 updated software is available as of yesterday.
We've updated both the Grinding Angle Setter and Frontal Vertical Base for Tormek applets in the part of T-4.
Testing has shown that the software works accurately for Tormek T-4.

Please see our YouTube video for how to update your applets:
https://youtu.be/DTq71b033OQ (https://youtu.be/DTq71b033OQ)

Cheers,
Vadim
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on June 27, 2020, 12:14:32 am
Hey Wootz... I have a couple of calculator questions for you...

I was programming a new calculator, and was using yours to check the answers... when I ran across a couple of things I had questions about.

When I change the blade thickness in the "Grinding Angle Setter" app, for example: T-4 WD:200 PD:139 A:20, I get the following...

0.2  165.42
0.5  165.05
1.0  164.45
1.5  163.84
2.0  164.51
2.5  163.94
3.0  163.36

... as you can see, the numbers decrease until 2.0 where it jumps back up, and then decreases again.  It also does this on the T-8 setting (WD changed to 250), you get a jump back up at 2.0, then starts decreasing again.  Is there a reason or an error?  I don't see this on the FVB calculator... it decrease all the way thru.

My second question... why does the main app change less than the FVB app between thicknesses?  The difference between 3.0 and 0.2 above is 2.06... the same range in the FVB is 4.32.  There a reason for this?

Also, (since my email went unanswered + I know I'm not the only one), how does a person who bought an FVB get the updated PIN # for the app?  I know it's not needed right away, but when a phone is switched or reset, the PIN is needed. ;)

Thanks!
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on June 29, 2020, 06:57:25 pm
Well, I have to say, my inadvertent discovery led me down an interesting path this weekend.  (Buckle your seatbelts)...

Wootz may not be aware, but a recent new forum member posted the code to his calculator.  So, I used it to program a calculator that matches the results of Wootz's calculator, to try and figure out what was going on here.  From that, I made an interesting discovery...

The "Blade Thickness" Correction:

Wootz states, based on page 6 of Dutchman's book, that blade thickness matters.  Now, if you read the entire section in the book, it only matters in certain circumstances.  But Wootz claimed it always matters, and his calculator now requires an entry for blade thickness, and uses it in the formula.  Now, keep this in mind... if you adjust for blade thickness, you shorten the Projection Distance, which results in a LOWER USB height.  And part of Wootz calculator does this.  But, there's more.  Enter...

The "Correction Factor":

Here's where things get a bit shall we say... interesting.  Wootz calculator has a second part that adds a "thickness correction" to it.  This correction takes a number based on the angle and blade thickness entered, and adds this correction back to the angle.  This results in a HIGHER USB height.  So, to be clear... the "correction factor" CANCELS the result of the Blade Thickness correction (partly or completely depending on the angle and blade thickness).

What's even more interesting is, the "Correction Factor" isn't tied to anything... it just makes "jumps" depending on the angle and thickness.  That's why I got the results in my earlier post because, at 2mm... it jumped to a higher correction.  (My guess here is, that just entering a blade thickness correction got so far off, he had to figure out a way to offset it... because there's no correlation to anything?)  If you want an example, from the post I made earlier, a blade with a .95mm thickness would give the same answer as a blade at 2.0mm thickness.  So, how does thickness matter...

So, why am i posting this?  Like I've said before, some of this doesn't matter... consistency does too, so if you're using the wootz calculator, stick with it, the actual numbers for the most part, aren't that different (and where they are, sometimes favors the sharpener).

It's because Wootz, repeatedly in this thread, made statements that "thickness matters" and even more importantly, that the other calculators being used were wrong not to include it.  For example...

...
I did trial sharpening by Jan’s formula / JVH _TormekCalc.xlsx with a knife 2.5 mm thick at the spine - the results:
...
If you have a laser protractor, you can see to yourself that neither Jan's formula nor _TormekCalc.xlsx by JVH grind to the exact angle, and the thicker the blade, the greater is deviation from the target.

While our updated Grinding Angle Setter and the FVB applet grind exact angle, as I’ve shown in the testing results.

... and repeatedly claimed how important thickness, and how accurate he is.  Then he creates a calculator that requires thickness be entered... but makes a correction to try and cancel it out?  (And, btw, his quote here is a bit false because the "thicker the blade" the more he corrects for it).  It certainly appears that it doesn't... and it also calls into question what was brought up earlier... the ability to measure the results he's given.

You be the judge..............

Title: Re: Grinding software upgrade is coming
Post by: Jan on June 29, 2020, 09:27:19 pm
CB, thanks for your analysis of the upgraded SW.

You are correct, but I am wondering why you did not mention that the upgraded SW still uses the old Dutchman formula? It is incomprehensible, isn’t it?

Jan
Title: Re: Grinding software upgrade is coming
Post by: cbwx34 on June 29, 2020, 10:20:10 pm
CB, thanks for your analysis of the upgraded SW.

You are correct, but I am wondering why you did not mention that the upgraded SW still uses the old Dutchman formula? It is incomprehensible, isn’t it?

Jan


True, and probably worth mentioning... I just thought of it as a separate issue than what was talked about in this thread.
Title: Re: Grinding software upgrade is coming
Post by: Jan on June 30, 2020, 09:49:23 am
I hope the upgraded SW will be corrected soon again.

In the past KG was issuing incorrect sharpness certificates saying that 100 on BESS ≈ 1 micron. After some time and several interventions from different sites in the world it was corrected by dividing the apex width by five! The initial error was not a misprint, it was done intentionally. The motivation was to speak the language of the local customers. The current KG certificate is OK.

The great role of constructive feedback, provided e.g. by CBWX, is to keep everyone on track and help to avoid major mistakes, namely in the concept.

Jan
Title: Re: Grinding software upgrade is coming
Post by: RickKrung on June 30, 2020, 06:15:34 pm
So, what is the correct relationship between apex width and sharpness and is there a way to relate that to BESS scores?  If I read your message correctly, it sounds like the apex width of a 100 BESS score would be about 0.2 micron. 

Is there reference material to look at?  Was this posted here and I missed it? 

Rick
Title: Re: Grinding software upgrade is coming
Post by: Jan on June 30, 2020, 07:58:54 pm
Yes Rick, you are correct. The apex width of 100 BESS score should be about 0.2 micron (200 nanometers).

The reference material is here: https://www.edgeonup.com/Support_Document.pdf

Jan
Title: Re: Grinding software upgrade is coming
Post by: dec11ad on April 17, 2022, 04:05:00 pm
A word on home-made FVBs.
4 months ago we started CNC machining the FVB base, and have tolerances tight.
If your self-made FVB does not have the base of the same thickness as ours or legs in the wrong position, you will be getting less accurate results, and all the man-hours we've put into this software improvement will be wasted as you will not be getting better deburring and sharpness with it.
I'll be stopping making custom applets for home-made FVBs because of that, because formulas by themselves will never match the algorithm fine-tuned to our particular FVB make.

Could you post or send me the measurements/print to the FVB so I can fabricate my own in our machine shop?