Tormek Community Forum

In the Shop => Knife Sharpening => Topic started by: benhung on April 25, 2023, 07:39:26 AM

Title: Chord-Tangent Angle Compensation
Post by: benhung on April 25, 2023, 07:39:26 AM
Hi,

New to the forum. I made a Chord-Tangent angle compensation sliding-diagram by GeoGebra. Don't know it's useful or not. I post it on forum for someone who is interesting.

Regards.

Benjamin

https://www.geogebra.org/m/abdqd8dj

d : Grindstone diameter.  α : angle.  t : blade thickness

-------------------------
Dutchman's Angle Setup Formula Diagram:
https://www.geogebra.org/m/wwuqbvhh

I add Dutchman's Angle Setup formula here. This is his origin model, also my calculator.  Present his theory only, can not be apply if you can not find out real Projection & Jig rotate radius.

-------------------------
TTS-100 Type - Jig calculator
https://www.geogebra.org/m/csmvmayb


20230505 Update:

This Diagram show how I find projection (k) & radius (f), not difficult.

https://www.geogebra.org/m/haxutcdv

Add USB base adjustment to Angle Setup Diagram.

https://www.geogebra.org/m/wndeq2gn

aslo post it on Dutchman's Link.

-------------------------
20230510 Update:

Tormek SVM-45 Version Calculator

https://www.geogebra.org/m/uk8cpnq7

Projection is Dutchmen's Projection (6mm different).

-------------------------
20230516 Update:

Tormek SE-77 Calculator

https://www.geogebra.org/m/cdc2mfcc

If you don't use chord angle as second bevel, set thickness t as 0.

-------------------------
20230521 Update:

Add parameter input box of "Blade Angle Setup", "SVM-45" and "SE-77" version.  Big thanks to cbwx34 for reviewing, testing & suggestions.

Title: Re: Chord-Tangent Angle Compensation
Post by: Dutchman on April 25, 2023, 09:59:56 AM
It helps if you describe what the use is and how you use it. ;)
Title: Re: Chord-Tangent Angle Compensation
Post by: cbwx34 on April 25, 2023, 03:35:32 PM
Quote from: benhung on April 25, 2023, 07:39:26 AMHi,

New to the forum. I made a Chord-Tangent angle compensation sliding-diagram by GeoGebra. Don't know it's useful or not. I post it on forum for someone who is interesting.

Regards.

Benjamin

https://www.geogebra.org/m/abdqd8dj

d : Grindstone diameter.  α : angle.  t : blade thickness

It looks like a "calculator" representation of what is described by Jan in this thread?

(https://forum.tormek.com/index.php?action=dlattach;attach=546)
https://forum.tormek.com/index.php/topic,3244.msg19184.html#msg19184

I too, would be curious how you use it.  (What do you mean by "angle compensation"?)

Pretty cool though!
Title: Re: Chord-Tangent Angle Compensation
Post by: benhung on April 27, 2023, 11:17:32 AM
Hi Ton,

I'm glad I can make conversation with you. I would like to say "Thank you!". Your booklet "More math for the Tormek grinder" help me a lots. I pick up some of you concept, made a motion diagram to help me setup T8. :)

I post the link bellow to show the amazing jobs you did, and how helpful it is. It also present the beauty of math that's described in your booklet. I try my best to draw the diagram same as your booklet's Figure 10 to show my respect. :)

I'll remove the link couple of days later. It's your concept, I don't think I have the right to show it in public without your permission. ;)

Benjamin

https://www.geogebra.org/m/wwuqbvhh (https://www.geogebra.org/m/wwuqbvhh)

I modify the link as English version.
Title: Re: Chord-Tangent Angle Compensation
Post by: benhung on April 27, 2023, 11:51:36 AM
Quote from: Dutchman on April 25, 2023, 09:59:56 AMIt helps if you describe what the use is and how you use it. ;)

I don't know how to describe, also don't know it useful or not? :)

By some reason, the angle of my chisel's blade has to be "given-angle + chord-tangent angle". Actually, I can not feel the difference. The difference is tiny, but it always be there. This situation irritates me a lot. You ask how I use it. I don't know. Maybe... the answer is "I use it to fix my stubbornness". ;)
Title: Re: Chord-Tangent Angle Compensation
Post by: benhung on April 27, 2023, 12:21:50 PM
Quote from: cbwx34 on April 25, 2023, 03:35:32 PMIt looks like a "calculator" representation of what is described by Jan in this thread?

Quote from: cbwx34 on April 25, 2023, 03:35:32 PM
Quote from: benhung on April 25, 2023, 07:39:26 AMHi,

New to the forum. I made a Chord-Tangent angle compensation sliding-diagram by GeoGebra. Don't know it's useful or not. I post it on forum for someone who is interesting.

Regards.

Benjamin

https://www.geogebra.org/m/abdqd8dj

d : Grindstone diameter.  α : angle.  t : blade thickness

It looks like a "calculator" representation of what is described by Jan in this thread?

(https://forum.tormek.com/index.php?action=dlattach;attach=546)
https://forum.tormek.com/index.php/topic,3244.msg19184.html#msg19184

I too, would be curious how you use it.  (What do you mean by "angle compensation"?)

Pretty cool though!

Hi cbwx,

Yes, it is just a calculator. It's not too hard to get chord-tangent angle's value, but has to take some massive steps. It's a small tool. If someone feel it useful, pick it up. If not, just let it be there.

Also thank you for your kindness, share your excellent jobs to newbies like me.

Benjamin
Title: Re: Chord-Tangent Angle Compensation
Post by: tgbto on April 27, 2023, 01:52:22 PM
Quote from: benhung on April 27, 2023, 11:17:32 AMhttps://www.geogebra.org/m/wgnjeedv (https://www.geogebra.org/m/wgnjeedv)


Hello,

It's nice to have it on geogebra, we can play with it and *see* how it varies. However, if red 'k' is the projection distance, shouldn't it also be set back 6mm along [GJ] on the off side of J ? And the typical 'f' distance would also be 6mm as the USB has a 12mm diameter, not radius. It is still usable this way if we make the corrections, so nice job anyway!
Title: Re: Chord-Tangent Angle Compensation
Post by: cbwx34 on April 27, 2023, 04:39:34 PM
Quote from: benhung on April 27, 2023, 11:17:32 AM...
I'll remove the link couple of days later. It's your concept, I don't think I have the right to show it in public without your permission. ;)

Benjamin

https://www.geogebra.org/m/wgnjeedv (https://www.geogebra.org/m/wgnjeedv)
...

Well, hopefully you can leave it up, because this is very cool.

Quote from: tgbto on April 27, 2023, 01:52:22 PMHello,

It's nice to have it on geogebra, we can play with it and *see* how it varies. However, if red 'k' is the projection distance, shouldn't it also be set back 6mm along [GJ] on the off side of J ? And the typical 'f' distance would also be 6mm as the USB has a 12mm diameter, not radius. It is still usable this way if we make the corrections, so nice job anyway!

I could be wrong, but I think some of this is the "behind the scenes" math, and what is actually being used.  For example "f" may be the "center of the jig" to the "center of the USB", not the actual diameter or radius of the jig.
Title: Re: Chord-Tangent Angle Compensation
Post by: tgbto on April 27, 2023, 06:29:58 PM
Quote from: cbwx34 on April 27, 2023, 04:39:34 PMI could be wrong, but I think some of this is the "behind the scenes" math, and what is actually being used.  For example "f" may be the "center of the jig" to the "center of the USB", not the actual diameter or radius of the jig.

You're seldom wrong. I, on the contrary...
Title: Re: Chord-Tangent Angle Compensation
Post by: benhung on April 28, 2023, 02:55:44 AM
Quote from: tgbto on April 27, 2023, 01:52:22 PM
Quote from: benhung on April 27, 2023, 11:17:32 AMhttps://www.geogebra.org/m/wgnjeedv (https://www.geogebra.org/m/wgnjeedv)


It's nice to have it on geogebra, ..........


Quote from: cbwx34 on April 27, 2023, 04:39:34 PM
Quote from: benhung on April 27, 2023, 11:17:32 AM...
I'll remove the link couple of days later. It's your concept, I don't think I have the right to show it in public without your permission. ;)

Benjamin

https://www.geogebra.org/m/wgnjeedv (https://www.geogebra.org/m/wgnjeedv)
...

Well, hopefully you can leave it up, because this is very cool.


This diagram is origin model developed by Ton. If Ton say it's OK, I don't mind leave it there.  Also can share my work sheet (GeoGebra's GGB file) to anyone who interest.  Very easy to modify it suit for various jigs, just change the value of factors. It can suddenly turn out to be a calculator with diagram, that's the way I setup my T8.

Benjamin
Title: Re: Chord-Tangent Angle Compensation
Post by: benhung on April 28, 2023, 09:33:24 AM
Quote from: cbwx34 on April 27, 2023, 04:39:34 PMI could be wrong, but I think some of this is the "behind the scenes" math, and what is actually being used.  For example "f" may be the "center of the jig" to the "center of the USB", not the actual diameter or radius of the jig.

hi cbwx,

You are not wrong, same as tgbto.  We are trying to find out the result, just approach it by different way.  Some way is easier, the other maybe complicate.  All of us can reach our goal when we keep it step by step.

I use a different way to approach it, assume point C is the centre of USB. When we bound jigs on USB, they are link together.  All machine parts are moving and rotating when machine is working, only Grind wheel's axle and USB are fixed. Wheel's axle is point A, jigs rotate axle is point C.  we adjust the distance of AC to get desire blade angle we want. It's done!

English is my 2nd language.  I hope I don't make things more confuse. I don't know how to upload picture  to explain it.  Sorry about that.

Benjamin
Title: Re: Chord-Tangent Angle Compensation
Post by: Dutchman on April 28, 2023, 10:29:09 AM
Quote from: benhung on April 27, 2023, 11:17:32 AM... snip
I'll remove the link couple of days later
...
https://www.geogebra.org/m/wgnjeedv (https://www.geogebra.org/m/wgnjeedv)
...
Hello Benjamin
Congratulations on your simulation of my angle setting formula.
I didn't understand your post, probably because I'm not familiar with 'GeoGebra'.
However, your explanation and the diagram in the new link gave the clarity I was missing.
You are right that it might explain a lot to new users especially regarding reference points. That's why I would be sorry if you removed the link. I would like you to add the link with some explanation as 'reply' to my topic, the link of which you will find in my 'signature',
Thanks in advance for your effort.
Title: Re: Chord-Tangent Angle Compensation
Post by: benhung on April 28, 2023, 11:15:03 AM
Quote from: Dutchman on April 28, 2023, 10:29:09 AM
Quote from: benhung on April 27, 2023, 11:17:32 AM... snip
I'll remove the link couple of days later
...
https://www.geogebra.org/m/wgnjeedv (https://www.geogebra.org/m/wgnjeedv)
...
Hello Benjamin
,,,,,

 I would like you to add the link with some explanation as 'reply' to my topic, the link of which you will find in my 'signature',


Hi Ton,

Thank you again about your great concept. Please give me couple of days to make an English version.

I'm also new to GeoGebra, I started it about a week ago.  It's very easy to use. I think you can easily handle it.

I'm sorry. The web page show "Author" name by default, can not be change.  I don't have GeoGebra account. Mr. Kuan is my cousin, he help me convert work sheet to web page.

That's why I need few day to modify it. I will re-post it when it is done.

Regards,

Benjamin
Title: Re: Chord-Tangent Angle Compensation
Post by: tgbto on May 02, 2023, 02:07:13 PM
Intrigued by @benhung's idea, I thought I might give geogebra a try.

Here's a first shot (https://www.geogebra.org/m/ax8zafyt), with the same naming conventions as in Jan's TormekCalc spreadsheet, so I could double check values. And guess what : R=125, TUSB = 78.9 and projection distance of 139mm gives ... a nice 15° angle! I assumed a fixed (top of) USB height above casing, but it would even be easier just setting TUSB.

The nice thing with GeoGebra is the only computation done uses Pythagora's theorem once. No need to master inverse cotangents like @Dutchman to set angles ;)
Title: Re: Chord-Tangent Angle Compensation
Post by: benhung on May 03, 2023, 02:15:46 AM
Quote from: tgbto on May 02, 2023, 02:07:13 PMIntrigued by @benhung's idea, I thought I might give geogebra a try.

Here's a first shot (https://www.geogebra.org/m/ax8zafyt), with the same naming conventions as in Jan's TormekCalc spreadsheet, so I could double check values. And guess what : R=125, TUSB = 78.9 and projection distance of 139mm gives ... a nice 15° angle! I assumed a fixed (top of) USB height above casing, but it would even be easier just setting TUSB.

The nice thing with GeoGebra is the only computation done uses Pythagora's theorem once. No need to master inverse cotangents like @Dutchman to set angles ;)

Well done!

Expect more sharing from you. Thanks!  :)

Benjamin
Title: Re: Chord-Tangent Angle Compensation
Post by: tgbto on May 03, 2023, 09:40:26 AM
Thank you for the kind words. I modified it slightly (https://www.geogebra.org/m/ax8zafyt) to fix a few bugs and so it is easier to read/understand. I still have a 1.5 difference in H_USB with TormekCalc which I can't explain...
Title: Re: Chord-Tangent Angle Compensation
Post by: Ken S on May 03, 2023, 11:16:29 PM
I have a request from a member to move this topic to knife sharpening. I have no problem with it in either group. I would like some feedback from the members before deciding.

Ken
Moderator
Title: Re: Chord-Tangent Angle Compensation
Post by: benhung on May 04, 2023, 01:37:45 AM
Hi,

I made a calculating diagram simulate TTS-100's design.  It can help you make your version TTS-100 type jig.  Hope it help.

https://www.geogebra.org/m/csmvmayb

I didn't out of topic, I did the chord-tangent line compensation on it. Same as previous, you have to figure out Ton's real projection to apply it.

Regards,

Benjamin

I add it at first page also.
Title: Re: Chord-Tangent Angle Compensation
Post by: cbwx34 on May 04, 2023, 02:58:10 PM
Quote from: Ken S on May 03, 2023, 11:16:29 PMI have a request from a member to move this topic to knife sharpening. I have no problem with it in either group. I would like some feedback from the members before deciding.

Ken
Moderator

That would be me.

I figured that since it's related to Dutchman's work, it would be more appropriate there.

As a sidebar, in GeoGebra, you can "turn on" the geometry part used to solve the Knife Angle calculator.  I found the different approaches taken by benhung and tgbto interesting...


IMG_0082(1).jpg

(Maybe I'm easily amused.)   ;)
Title: Re: Chord-Tangent Angle Compensation
Post by: tgbto on May 04, 2023, 04:02:52 PM
Quote from: Ken S on May 03, 2023, 11:16:29 PMI have a request from a member to move this topic to knife sharpening. I have no problem with it in either group. I would like some feedback from the members before deciding.

Ken
Moderator

No objection, Sir. At least for the part I designed, it works with the knife jigs only, due to the way their handle lies on the USB.
Title: Re: Chord-Tangent Angle Compensation
Post by: Dutchman on May 05, 2023, 10:27:46 AM
Under the date header '20230505', I added info, including URLs, about Benjamin's graphics in my topic "Simple adjustment ..." (https://forum.tormek.com/index.php/topic,1849)
Title: Re: Chord-Tangent Angle Compensation
Post by: Ken S on May 05, 2023, 12:10:57 PM
I will move the topic.
Ken
Title: Re: Chord-Tangent Angle Compensation
Post by: benhung on May 10, 2023, 05:34:24 PM
I made a diagram for SVM-45.

https://www.geogebra.org/m/uk8cpnq7

Link is also added in first page.

Benjamin

Ps.
Anyone who need a special version for your own(design) jig, give me a mail.  I can make one for you, just give me your jig's dimensions & photo. :)
Title: Re: Chord-Tangent Angle Compensation
Post by: cbwx34 on May 17, 2023, 03:25:54 PM
One thing I found, is that the Sliders don't work well on a phone.  I managed to figure out how to convert them to Inputboxes...

IMG_0669.jpg

...(that's a screenshot from my phone.) Between that and making the font larger (32pt in this example), it works a bit better.  With your knowledge/skill, you could probably come up with better ideas.
Title: Re: Chord-Tangent Angle Compensation
Post by: TomP2 on February 11, 2024, 11:28:15 PM
Hi, I am a complete Newby and read this thread carefully. There is one thing I still do not understand: the USB Base point (height). What is it needed and adjusted or measured? Maybe it is a dumb question, but I don't currently own a Tormek.
Thanks for understanding and support!