How To How To Measure Freehand Edge Angles?

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MtnHawk1

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May 22, 2019
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I often read posts about knife edge bevel angles and would like to know what mine are (I freehand sharpen) without buying an expensive measuring device or getting into complicated procedures or calculations. I've seen inexpensive devices, such as small circular bevel gauges with cut-out angles around the edge, but I'm not sure how well they work for knives. They seem to be for woodworking tools such as chisels rather than relatively tiny knife edge bevels.

If it's not possible to do this without spending big bucks or a lot of time I'm good with that, just don't want to continue looking for something that may not exist. I did some searches but couldn't find much relevant. If there is an existing thread regarding this subject I'd appreciate the link.

Thank you...
 
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The easiest way isn't TECHNICALLY the actual angle but is a close enough approximation for all practical purposes--simply find a hard but cuttable flat surface like a piece of plexiglass, lay the blade flat on the surface, then slowly start tilting the spine up. As the edge appears to near the surface of the material, make slight back-and-forth pushes on the blade without any downward pressure, and when the edge JUST starts to catch, your edge angle is just a hair below that.

However, for a cheap and accurate bevel measuring tool, a digital protractor rule works great. A company called iGaging makes some very solid stainless steel ones that work well for the task. I recommend their 11" model or longer since it helps give you more bevel contact at low angles. Cost is about $20
 
When I started dialing in my freehand, I scribed a bunch of lines on the block of wood I used for a stone holder. When starting I would sight down the midpoint of my spine and align with the line that matched my intended angle.

Every so often I would stop, remove the stone and check per 42's suggestion above - lightly push the edge along the wood to see where it starts to hitch. Put the stone back on and continue.
 
MtnHawk1 said:
I often read posts about knife edge (secondary bevel) angles and would like to know what mine are (I freehand sharpen) without buying an expensive measuring device or getting into complicated procedures. I've seen inexpensive devices, such as small circular bevel gauges with cut-out angles around the edge, but I'm not sure how well they work for knives. They seem to be for woodworking tools such as chisels rather than relatively tiny knife edge bevels.

If it's not possible to do this without spending big bucks or a lot of time I'm good with that, just don't want to continue looking for something that may not exist. I did some searches but couldn't find much relevant. If there is an existing thread regarding this subject I'd appreciate the link.

Thank you...
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Hi

You can also do it sharpmaker style,
hold a stick verticallly, then tilt it 15 degrees (check with phone?),
slide knife, if it catches, thats your angle
...
two sticks and a screw and plastic protractor in place of pohone


Do you have a one dollar laser pointer and a box?
jasonstone20 makes basic verhoeven version Re: Making Your Own Goniometer: How To?
1589911690770666102762.jpg

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Clip-on version
https://dschep.github.io/imgur-album-downloader/#/xTma1cJ
imgur.com/a/xTma1cJ
... ... ... ...


update: another way is to measure edge thickness and bevel width using digital calipers and punch the numbers into a triangle calculator
 
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bucketstove said:
update: another way is to measure edge thickness and bevel width using digital calipers and punch the numbers into a triangle calculator
Click to expand...
This works if you have perfectly flat bevels, but the more convex the bevel, the less accurate it will be.
 
FortyTwoBlades said:
The easiest way isn't TECHNICALLY the actual angle but is a close enough approximation for all practical purposes--simply find a hard but cuttable flat surface like a piece of plexiglass, lay the blade flat on the surface, then slowly start tilting the spine up. As the edge appears to near the surface of the material, make slight back-and-forth pushes on the blade without any downward pressure, and when the edge JUST starts to catch, your edge angle is just a hair below that.
Click to expand...

Would this technique work using a digital angle gauge to measure the edge bevel angle? I think I've read about this before somewhere.

This is my understanding (hopefully correct) of how it works: The gauge (some have magnets) is set to zero on the knife blade on a flat surface (in this case the plexiglass), then after the spine is tilted up and the edge catches that angle reading is taken from the gauge.

Has anyone heard about this method? Does it work?

I'm not looking for exact angles, just good approximations. Thanks...
 
Magnetic angle cubes won't work for this purpose--they're too large and bulky. With the protractor you just use it like the little cheap-o bevel gauges but adjust the angle until it matches that of the knife. Easy, quick, and accurate. The apex should be able to *just* touch the bottom of the angle for the reading to be correct.
 
Free hand is just that. No need to measure, use your eyes. Know how the blade looks and feels when you find the angle you like for the edge you get. Practice until muscle memory is ingrained and the right angles occur without much conscious thought. When you can do it without looking directly at it then you got it.
 
SOLEIL said:
Free hand is just that. No need to measure, use your eyes. Know how the blade looks and feels when you find the angle you like for the edge you get. Practice until muscle memory is ingrained and the right angles occur without much conscious thought. When you can do it without looking directly at it then you got it.
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I agree, and like to think I am doing this already.

Knowing the edge angles of my freehand-sharpened knives, and how this is determined, is just another aspect of sharpening I am curious about. It's not going to make any difference in how I sharpen. I often read about angles that others sharpen to and just wondered what mine are.
 
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Dirt said:
I certainly don't have the experience of some here, but I just take a marker along the blade and when I have the ink coming off evenly I know I have the original angle.
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I'm aware of this technique, but it doesn't tell what the edge bevel angle is. I think it does with guided systems that tell you the sharpening angle, but I freehand sharpen.

Thanks for the info about the wedges. I think they are a good idea and good product, but I have them and don't find them particularly useful for how I sharpen
 
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