Freehand Sharpening with Microscope Pics

Discussion in 'Sharpening Station' started by The Edge, Oct 14, 2019.

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  1. Oct 14, 2019 #1

    The Edge

    The Edge

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    Took some pics this weekend of my sharpening process. Pictures are 1 mm wide and 1 mm high (edited with correct picture size, thanks Matus). Process for each stone was to raise a burr on one side, flip the burr, and then reducing the burr until I couldn't feel it with my fingers anymore. I've always thought it was harder to de-burr on a courser stone, and I think this backs it up.

    Up first, is a pic with no edge at all, and just a 150 grit sandpaper finish:
    No Edge.jpg
    Next picture is 120 grit dmt burr raised and flipped. The dark area is the steel starting to curve up to a bright line that is the edge of the burr.
    120 DMT Burr formed and flipped.jpg
    Next, I've sharpened until I could no longer feel the burr, and the edge felt toothy. You'll notice that there is a small wire edge still left on the knife at this point.
    120 DMT Finished.jpg
    From there, I switch to a 600 grit splash and go stone. The next picture is after I've raised the burr, flipped it, and then reduced it until my fingers felt a toothy edge. You'll notice that the wire edge is starting to rip off, but is still present along most of the edge. I was a bit surprised by this one.
    600 Grit Finsihed.jpg
    Next, I do a larger jump, going to 6k. Same as before, raised a burr, flipped it, and then stropped, edge trailing, until I felt the knife was sharp. There are only a few spots where small micro-burrs are still attached, and at this point, I'm not sure how much they would even affect performance, other than maybe catching in paper slightly.
    6k Grit Finished.jpg
    Last, I stropped on a cheap leather bench strop loaded with chromium oxide, and then a light cut into hard felt. Maybe not as toothy as some prefer, but for me, it can slice a tomato with almost no effort, and cooking for 2 everyday, the edge will last me about 4 months. Granted how long an edge lasts is more dependent on how someone uses a knife, and what surface they are cutting on. Steel is AEB-L @~62 hrc.
    Stropped and De-Burred.jpg
    Thanks for looking!
     
    Last edited: Oct 15, 2019
  2. Oct 14, 2019 #2

    chinacats

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    Very helpful...i would suggest a bit more work on cleaning the edge (as i believe you understand) w the lower grit stones...
     
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  3. Oct 14, 2019 #3

    The Edge

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    If I was finishing on those stones, I would agree with you, but in the end, it didn't matter. Yes, I'm sure if I spent more time on those stones, rather than the 5 minutes I spent on the entire process (not counting pictures), that I could get them to look better. Just depends on what the end goal is.
     
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  4. Oct 14, 2019 #4

    kayman67

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    It's all down to pressure and technique. But it wasn't about those directly.
    This wasn't a best possible scenario, but more like you wanted to see what happens with your scenario. And I get why ;)
     
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  5. Oct 14, 2019 #5

    Michi

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    Thanks for that post! I assume that you used a USB microscope for the pictures? If so, what model?

    I previously tried a Celestron USB microscope, which was an unmitigated disaster. The software (for OS X) was not just bad, but completely unusable. I ended up returning the thing. If someone knows of a USB microscope that works with OS X and doesn't cost more than $200, I'd be keen to hear about it!
     
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  6. Oct 14, 2019 #6

    The Edge

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    Correct, I am using a USB microscope. It's an AmScope MD200. Not sure how it works with OS X, since I'm still stuck in the stone ages with Windows 7. It's fairly limited with the USB attachment, only zooming in to this resolution. Eventually, I'll invest in something much nicer, but for now, I'm just going to have to make due.

    And you're very welcome!
     
  7. Oct 14, 2019 #7
    This is quite cool, thanks for sharing.

    However comparing to what I can see through my optical 100x microscope I would say that the image size is at least 100 microns linearly and most likely even larger. Not only the size of the scratches would suggest that, but also if the images were really only 10 microns wide, than this would mean that the USB microscope is giving you effective resolution of around 50 nanometers what is physically not possible with visible light microscopy. To test it try to have a look at a structure you can still resolve with a naked eye and compare to something (i.e. a human hair, a scale on a fine ruler or such).
     
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  8. Oct 15, 2019 #8

    The Edge

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    That's what I get for trusting the measurements on the screen. I pulled out the calibration slide, and the width is actually 1mm. Dohhh. Thanks for pointing that out. I need to remember to always double check the computer! (Note, edited above to show the correct measurement)
     
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  9. Oct 15, 2019 #9

    ian

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    Oh, good point. I guess in contrast, this is around 20 microns wide. (From scienceofsharp.)

    [​IMG]

    Thanks a lot for the pics, @The Edge. This is a great thread. Have you tried out edge leading instead of trailing for burr removal? I'm an evangelist.

    It's awesome how much you can see in your images, given that one can presumably make them without spending thousands of dollars. I'm inspired to check out my edges too.
     
  10. Oct 15, 2019 #10

    The Edge

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    I used to do that exclusively, but switched to edge trailing years ago for some reason or another. I'll probably go back and do more comparisons when I have another knife that needs to be sharpened. I'll probably do both edge leading, and trailing strokes, and I may actually take my time on each stone to show the finished states. Especially since I have a few other stones that I could play around with.
     
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  11. Oct 15, 2019 #11

    ian

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    Looking forward to the pics! Keep us updated.
     
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  12. Oct 15, 2019 #12

    GoodMagic

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    Awesome, thanks for taking the time to do this, I appreciate it. Would love to see other progressions, especially 1 k to 3k-5k, as that is my most used progression for edge maintenance.
     
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  13. Oct 15, 2019 #13

    kayman67

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    Guys, keep in mind that you see the progression of a particular sharpening style, not of grits in definitive terms. I guess this is always the case, but here even more. I really liked the idea of doing this to see how things evolve with a particular approach.

    I remember that 120 DMT being very brutal. Was it worn-out here?
     
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  14. Oct 15, 2019 #14

    The Edge

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    Yeah, this one is on its final legs. Still removes steel, but definitely not nearly as aggressive as used. And thank you!
     
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  15. Oct 15, 2019 #15

    bahamaroot

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    I've been wanting to get a USB Microscope for ages to do exactly this. This just might be the last push I needed to do it!
    Thanks for taking the time to do and post this, a really enjoyable thread.
     
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  16. Oct 15, 2019 #16

    Kippington

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    They're insanely cheap - I say do it.
    I'll also say that optical microscopes don't seem to tell you a whole lot about what's happening at the very edge, where it matters most - unless there's something terribly wrong.
    I enjoyed mine while it lasted, but didn't miss it when it died.
    [​IMG]
     
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  17. Oct 15, 2019 #17

    The Edge

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    Very true it doesn't give you the entire picture, but it can help out with some of what's going on at the edge. This model was cheap, and I'd love to actually get a metallurgical tricscope with dark and light field options, since it would be nice to get more information for my heat treatment (though I go back and forth with this, as it could be just as expensive to have someone else do the testing for the cost of the equipment).

    I visited a friend a couple months ago, and we had a great discussion about grinds and sharpening progressions. I'm thinking I could have gotten an even smoother finish with the 6k, but wanted to check out this method. Just gives me more tests to run!

    Love seeing your work and experiments btw! Even though I think I know a lot, this forum has expanded on that knowledge, and led me down countless other rabbit holes. Meanwhile, I'll drop a video of how the edge performs on a tomato:
     
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