What Angle Is This Knife Sharpened At?

[cbwx34]

The pictured knife has a side taper of 3° per side. 

The Angle Master, sitting on the taper area, reads 25°. 

What angle (per side) is the knife sharpened at? 

[Fedor]

Is it a matter of holding a quiz? A question on wits?
If you need an exact answer, it's best to use:

http://ermak-laser.ru/services/lazernyj-uglomer-ermak-50/

http://www.catra.org/pages/products/kniveslevel1/lgpm.htm

http://www.catra.org/pages/products/kniveslevel1/lkep.htm

Or use the method as in this video:

https://youtu.be/3ICnxj6TDjs

Yours faithfully Fedor.

[Fedor]

I apologize for the offtopic.
For lifehack you will need:
Laser modul:

https://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=High+Precision+635nm+5mW+Red+Line+Laser+Diode+Module+for+Marking+device&_sop=15

The transporter with his own hands:

http://www.luaz967.ru/compiz/transportir-svoimi-rukami/

https://yadi.sk/i/3HXvbXIP3UBxR2

We get

[cbwx34]

Is it a matter of holding a quiz? A question on wits?
If you need an exact answer, it's best to use:

Thanks for the reply.  Just a "thought provoking" quiz.  (No question of "wits", answers can be anonymous).

Good thoughts though!

[SharpenADullWitt]

Try the OUTSIDE of the anglemaster.  What angle does it fit, divide in half.

[cbwx34]

Try the OUTSIDE of the anglemaster.  What angle does it fit, divide in half.

The answer is in the question... no measuring needed. 

[bisonbladesharpening]

I look at it just like a secondary bevel, so 22 plus 3 =25 from the spine of the knife.
Sharpening angle should be 22.

[SharpenADullWitt]

Try the OUTSIDE of the anglemaster.  What angle does it fit, divide in half.

The answer is in the question... no measuring needed. 

No, no measuring needed, because it is already set.  That doesn't mean I don't think some future reader will get the idea this is the way you are supposed to use it.

[cbwx34]

Try the OUTSIDE of the anglemaster.  What angle does it fit, divide in half.

The answer is in the question... no measuring needed. 

No, no measuring needed, because it is already set.  That doesn't mean I don't think some future reader will get the idea this is the way you are supposed to use it.

Not sure I understand your thinking... measuring the angle on the side of the Angle Master, won't tell you what angle you're sharpening at.

Edit to add:  I might understand the disconnect here... I'm just looking for... what angle is the knife being sharpened at (before sharpening), not seeing what it is after it's done.

[Fernando]

Is it a matter of holding a quiz? A question on wits?
If you need an exact answer, it's best to use:

http://ermak-laser.ru/services/lazernyj-uglomer-ermak-50/

http://www.catra.org/pages/products/kniveslevel1/lgpm.htm

http://www.catra.org/pages/products/kniveslevel1/lkep.htm

Or use the method as in this video:

https://youtu.be/3ICnxj6TDjs

Yours faithfully Fedor.

It would be great to have such a tool

[cbwx34]

The answer....

The AngleMaster, if used according to the manual, sets the angle being sharpened based on the area above the bevel, as seen in the Tormek Handbook...


... however this assumes a flat surface above the bevel...



...to correctly set the sharpening angle.  Most knives however, as shown in the original question, have a "secondary grind" that is also angled, throwing off the AngleMaster...



... so if you want to sharpen the knife at 25dps, you set the angle at 28°...



... and if the AngleMaster is kept at 25°, the sharpening angle is actually 22°...



So, the answer in this example was 22°.

Thanks for playing! 

My next poll may be... do you like polls?

[WolfY]

If measuring on the Primary bevel, e.g the blade and it is not straight but have an angle like in your case, I deduct the degrs from the reading like you did. I don't measure it so precisely but know that for kitchen knives it is normally about 1.5dgrs/ side.
Exactly like explains in the Tormek bible + self thinking/ understanding 

[wootz]

@cbwx34 - as much as the upper side of the blade "throws off" the angle by 3 degrees, the other side does the same in the opposite direction, and in the end you get on your edge what the AngleMaster shows, don't you?

[cbwx34]

@cbwx34 - as much as the upper side of the blade "throws off" the angle by 3 degrees, the other side does the same in the opposite direction, and in the end you get on your edge what the AngleMaster shows, don't you?

If the AngleMaster was being placed directly on the bevel being sharpened, as seen in the top photo...



... you would be correct.  But when it's placed on the secondary bevel, as in the bottom of the photo, and that bevel has an angle... it effects the reading, but doesn't "cancel out".

BTW... that is one advantage of using something like your calculator... it measures the "true" angle, and you don't have to deal with this.

If measuring on the Primary bevel, e.g the blade and it is not straight but have an angle like in your case, I deduct the degrs from the reading like you did. I don't measure it so precisely but know that for kitchen knives it is normally about 1.5dgrs/ side.
Exactly like explains in the Tormek bible + self thinking/ understanding 

Yea... a good "rule of thumb"... a degree or two for kitchen knives, 3-4 degrees will cover most pocket style knives, etc.

[cbwx34]

BTW... that is one advantage of using something like your calculator... it measures the "true" angle, and you don't have to deal with this.

In fact, I'll expand on this a bit...

I took a knife that had a decent secondary bevel, measured the dimensions, and calculated it with a "Triangle Calculator"...




... this came out to around 11.5°, so about 6° per side.

I then set the angle using the "Knifegrinders Calculator" to 20° per side...



Now comparing it with the AngleMaster set at 20°...



vs. setting it to "correct" for the secondary bevel at 26°...



shows the adjustment that is needed.

p.s.  Don't confuse it with measuring directly to the primary bevel(edge angle in the Tormek manual)...



... that would be set to the total angle being sharpened = 40°