Testing Edge Angle.

[nozh2002]

Recently I had to develop some method to measure edge angle. Idea is to make clue in the clay and make shot of it using digital camera close up. Having picture of this clue it is easy to measure it on the screen using protractor.

I tried first thin piece of clay, but found that it easy to deform, because it kind of stick to edge. So I deside to make thicker piece, but with it being thick side should be flat so it will not affect look of the angle. I uses piece of wood with clay to make sure one side is flat. It is easier to show then explain.

1. Stick clay to wood:

2. Cut top with knife - make sure edge is perpendicular to wood surface:

3. Remove clay from wood - better delicately shake it off, preventing any deformation. Shoot close up using Digital Camers:

4. Check angle with protractor.
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This is Busse Game Warden in two parts of the my edge (in the middle of the belly and at the bottom of the belly) both about 28 degree (you may check it for youself):

This is Busse Meaner Street Red G10 with factory edge 31 degree:

This is my edge on Yuna Hard II 26 degree:

This is my edge on Spyderco Mule CPM M4 22 degree:

This is not yet final method - just some experiment and I like to discuss this if you have any idea, is it good or bad or anything wrong and may be improved, may be someone try this too and report his/her observations?

Thanks, Vassili.

 

[mmmotorcycle]

And it is a very interesting method. I am unsure how you sharpen your knives, exactly, but this method seems like it could work best with zero ground edges without micro bevels.

 

[markksr]

I really doubt that this method is very accurate. Even the slightest "wiggle" from side to side could skew the results.

 

[richard j]

i wouldnt rely on it to be accurate

 

[hardheart]

how about using a clay/other substance that hardens. coat the edge in an oil or something to keep it from sticking. Once hard, you could section it to then photograph.

 

[nozh2002]

i wouldnt rely on it to be accurate

Why?

Thanks, Vassili.

 

[mmmotorcycle]

Why?

Thanks, Vassili.

Unless you insert the knife into the clay at a perfectly perpendicular angle, it will not be an accurate test. Perhaps if you developed a method of insertion steadier than your own hand?

 

[nozh2002]

how about using a clay/other substance that hardens. coat the edge in an oil or something to keep it from sticking. Once hard, you could section it to then photograph.

It take way more time and I an not sure result will be different from what I an doing. Material need to be without any even minimal resistance to deformation after cut is made, from other hand it need to be strong enough to not to deform before picture taken - it seems it does work so far.

Thanks, Vassili.

 

[nozh2002]

Unless you insert the knife into the clay at a perfectly perpendicular angle, it will not be an accurate test. Perhaps if you developed a method of insertion steadier than your own hand?

I think I can do perpendicular enough with hand. At least to expected precision.

Thanks, Vassili.

 

[mmmotorcycle]

Also, depending on the type of clay, it might be best to slide it through the clay seeing as pushing it could result in some sort of deformation. I could be wrong though.

 

[just10minreader]

It take way more time and I an not sure result will be different from what I an doing. Material need to be without any even minimal resistance to deformation after cut is made, from other hand it need to be strong enough to not to deform before picture taken - it seems it does work so far.

Thanks, Vassili.

Do one (or two) to see if it makes a difference in the results you get.
You can always use superglue to speed things up, or even just icewater.

I think wet felt or newspaper and superglue might work, say if enclosed in a a piece of halfpipe

 

[just10minreader]

I stumbled upon this after a few simple searches

Measuring Edge Angle - £5 laser goniometer - British Blades :: Custom Knife Making

 

[nozh2002]

I stumbled upon this after a few simple searches

Measuring Edge Angle - £5 laser goniometer - British Blades :: Custom Knife Making

I guess it can be done using chaep lazer pointer.

Thanks, Vassili.

P.S. But it require mirror polished edge.

 

[2brothers]

Lubricate the blade with oil, WD-40 etc.. and stick it into a container of melted wax.
When the wax hardens (it will not shrink), pull the blade out.

mike

 

[nozh2002]

More edges:

Buck CS 110 BG42 G10 factory edge - 23 degree

Buck 110 factory edge - 21 degree

Buck 110 BassPro - CPM 154 - 22 degree

Buck 110 Alaskan Guide - CPM S30V - 22degree

Buck CS 110 BG42 Birch - 21 degree

KaBar Dozier folding Hunter D2 - 25 degree

Dozier KS1 - 25 degree

Dozier KS7 - 20 degree

Thanks, Vassili.

 

[markksr]

If you can't see for yourself that some of those are crooked and therefore not accurate, well, then I guess nothing anybody says will get through to you...

 

[Cobalt]

If you can't see for yourself that some of those are crooked and therefore not accurate, well, then I guess nothing anybody says will get through to you...

 

[lazerboy2000]

Perhaps you could somehow attach the knife handle to a drill press, and then use that to ensure a purely vertical, and consistent movement each time. Otherwise your idea is pretty creative and more accurate method than any I've got.

 

[Knife_Geek]

I'm sorry nozh2002 this method of testing just is not nearly accurate enough to be worthwhile. It is far to easy to distort the angles on the way in and also on the way out. I think the only way to measure something like this would be the purpose built measuring equipment available to knife manufacturers or with a good bit of practice using the method posted on britishblades.com

 

[nozh2002]

I'm sorry nozh2002 this method of testing just is not nearly accurate enough to be worthwhile. It is far to easy to distort the angles on the way in and also on the way out. I think the only way to measure something like this would be the purpose built measuring equipment available to knife manufacturers or with a good bit of practice using the method posted on britishblades.com

Of course distortion may happen and idea with drill press may very help - I have some for Dremel. also regular wise may be used as well. But even with hand it is pretty stable - because wood, especially when you penetrates deep stabilize position and then you may pretty controllable take it out by lowering handle which is behind wood, so edge lifted slow and without moving side by side. I will try to make more photos or video to explain it better.

Thanks, Vassili.