Tool Edge Micrographs

Discussion in 'Woodturning Discussion Forum' started by Jeff Gilfor, Jul 22, 2014.

  1. Jeff Gilfor

    Jeff Gilfor

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    Seriously Mark? Maybe a project for sometime in the future.

    Here are my plans for this weekend photos:

    Compare:
    CBN dry wheels at 80 and 120
    Tormek grey wheel at 220 (rough graded) and "1000" (fine graded) unhoned and honed edges.
    Tormek CBN wet wheel (280 grit) unhoned and honed

    I will also photo a fresh/unused surgical scalpel blade for true "scary sharp" comparison, and will find some scale reference to place with each micrograph.

    I will put this together as a single PDF document, an will post it in this thread (or a link to it anyway). That way, it will be easier to understand and use. It will also allow me to provide higher resolution and a size that is more conducive to presbyopic vision (old eyes).
     
  2. hockenbery

    hockenbery AAW Advisor Staff Member

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    Jeff,

    These are really nice images.
    I look forward to seeing round 2.
    Thanks for doing these.

    Al
     
  3. Dennis J Gooding

    Dennis J Gooding

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    Jeff, just to get sense of absolute scale of these pix, would it be possible to lay a fine wire of known size, say 30 gauge along gouge when you take one of the pix?
     
  4. Mark Mandell

    Mark Mandell

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    Excellent idea, but more appropriate when doing wear studies with different alloys. I seem to remember such a study done some years ago with PMs in various alloys. IIRC it sort of debunked the justification for the difference in price between V-15 and 2060 over their lesser cousins, A-11 and 2030, for bowl gouges.
     
  5. Gretch Flo

    Gretch Flo

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  6. Mark Wollschlager

    Mark Wollschlager

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    Sorry. I thought it seemed reasonable.
    A mirror shined sharp gouge on the shelf is a trophy.
    regardless of the method used to obtain the shine.
    The goal is to turn something with the tool, right?
    At what point would I need to return to the sharpening system to keep the high quality cut.
    I guess there are way too many variables to be objective.
     
  7. john lucas

    john lucas

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    Mark I was at that demo and the test results really didn't duplicate turning very well. He used odd angles on the tools and I forget what else we discussed later that left us with dubious results on his tests. I'm doing a comparison on how sharp the 3 types of tools get, Powdered metal, HSS and High Carbon Steel. I'm still trying to figure out a way to do some kind of test to get some wear results and then get micro photographs. That may take a while since I'm getting ready to start battling the Prostate Cancer I have. Hopefully it won't slow me down for long.
     
  8. Mark Hepburn

    Mark Hepburn

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    John,

    Off topic here but I had prostate cancer (Gleason 7) and underwent a RRP just over two years ago. Because of other health issues I wasn't a candidate for brachiotherapy or chemo. So out with the prostate and here I am two years later cancer free and with no lingering post operation issues. I'm glad I did it. Took about six weeks to get back to work and feeling somewhat normal again, though.

    I know some may think this is "too much information" but c,est la vie. I researched like a madman and feel like i made the best choice. Now it happens that three friends in my office have recently been diagnosed so we have spent a good bit of time discussing.

    I wish you well in your battle,


    Mark
     
  9. hu lowery

    hu lowery

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    ouch and a suggestion

    A time when the off topic is more important than the thread subject. John, good luck with your treatment. I have never had cancer but there have been a couple of biopsies. I do know even maybe preys on the mind, having to be treated has to be far worse. Wish there was more to offer to help but at times like this others are pretty helpless. I do know you have a world of friends just on the turning sites to support you.

    Jeff,

    Maybe just a finely graduated steel rule by your edge for reference or open a mike or caliper to a set distance the same in each picture to give an idea of scale. Shouldn't need to be too complicated. Any kind of standard will work, even laying the shank of the same drill bit by each piece photographed.

    I do much appreciate what you are doing and don't want to turn a simple thing into a monster project. I made the mistake of mentioning that my CAD software could position objects on a ten mile radius map within 3/8" of where they were reported to be. A few minute upgrade on a drawing turned into a three month project! Was worthwhile though, radiation monitoring sites if we had a release at the nuke.

    Thank You for doing this!

    Hu
     
  10. Jeff Gilfor

    Jeff Gilfor

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    Mark... Glad you are okay. As a physician who does that sort of surgery all the time, it can be very daunting to wade through all the information.

    Sorry, didn't mean to sound flip. I have so many things to do for this project this weekend, that I don't think I'll even get to do any real woodturning. Oh well. Shop needs cleaning anyway.

    I am going to try to find something here at the hospital that will show micro millimeter rulings. Don't have a ruler at home that has that much resolution.

    I do think it would be nice to see how long it takes to dull an edge, o remove a burr. There's a lot of conjecture out there, but no real experimental data that I know of. Maybe we can generate some here. My problem with that is, I think I can only accurately do that test with a scraper. The angle of attack, even in bevel rub mode, greatly affects the amount of wear placed on a blade. Scrapers, on the other hand can be pushed into the wood in identical fashion time and time again. Unless someone has a better idea, I think that's how I shall proceed.

    Oh, and I definitely want to test burr durability... For Robo.
     
  11. john lucas

    john lucas

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    Jeff I'm making some chisel shaped tools for my test with the edge square across like a carpenters chisel. I've been thinking about putting the chisel in my metal lathe. advance the cut a known amount into the work as it rotates and then use the power feel to go from one end of a turning to the other. maybe make 2 or 3 passes with each tool and then look at the edges. Don't know if that will be enough to really dull them. I would have to use 3 pieces of wood all cut from the same board so maybe the variable wouldn't be too bad. These tools would be the same ones that I will have sharpened by a professional sharpening service so hopefully the edge would be about as good as it can get.
     
  12. Jeff Gilfor

    Jeff Gilfor

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    John. I think that sounds about as controlled an experiment as you can get with this sort of thing. If you do that, I'll do the others. The only thing I can think of, is that the force exerted on the edge of a turning gouge is higher per unit than a square gouge. It should skew the results towards longer edge life... At least that's my guess. Still a useful experiment.
     
    Last edited: Jul 25, 2014
  13. Mark Hepburn

    Mark Hepburn

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    Thanks Jeff. You're certainly right about the quantity (and dubious quality) of information out there. And I have to say that, having been through it, I have a real respect for those of you who are called to the profession. Now THAT is daunting!

    You'll make Robo a happy man if you can do that :)
     
  14. Gretch Flo

    Gretch Flo

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    John. Best of luck. Attitude is eveything!!! Gretch
     
  15. Mark Hepburn

    Mark Hepburn

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    This may be a dumb idea, but how about using some MDF formed up into blanks? It's a consistent medium and from what I understand not too forgiving to turn with? Just a thought.
     
  16. Mark Mandell

    Mark Mandell

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    Don't count on that result, John. I tried that with a couple of guys in my area just to see how they would do. Chisels came back with nice sharp burrs on even hollow-ground bevels that lasted about a inch in wood and then went dull. Except for large saw blades I do all my own sharpening now; from hand tools to chain saws.
     
  17. john lucas

    john lucas

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    Mark this guys knives are exceptional. I doubt they will come back with a burr. I just got the first 2 chisels done today. The Powdered metal and the HSS. I ground the angles identical and it came out to 28 degrees. I sharpened them on my scary sharp system. Man are they sharp. So far I can't tell the difference in these 2 in sharpness. Cuts paper effortlessly and or course cuts hair. I'm tempering the High Carbon steel to 60 rockwell and will sharpen it tomorrow after it cools down.
    I am thinking about running a test after I get them back and photograph the edge. If I put a piece of wood on my metal lathe and set the tool in carriage at the same angle I can advance the tool into the wood maybe .100" and let the power feed run it across the wood. Do this about 3 or 4 passes or until the I think the tool isn't cutting the same and then try to rephotograph the edges. Do you think this would roughly be accurate at all.
     
  18. Mark Mandell

    Mark Mandell

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    Hi John,

    No intent to take anything away from your "guy." A good job done is always worth it.

    Noting on your carbon steel. I know you know enough about steel to know that until you get to the molecular level, any alloy will sharpen to the same degree of fineness provided you use the same abrasive on each. It's an internet myth that Carbon Steel will give a sharper edge than High Speed or high alloys. The determining factor is the abrasive. A 400 grit wheel will leave a 400 grit edge on everything it touches. Carbon steel "can" be taken to a finer edge than ASP-2060 or V15 because of its smaller crystalline structure, but you need very special equipment, far beyond anything we woodworkers (or your sharpening guy) have to use.

    It'll confirm that HHS and PM are more durable than carbon. But you already know that. The pix will be fun, however, to see how much each edge is degraded.
     
    Last edited: Jul 28, 2014
  19. john lucas

    john lucas

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    I've been toying with using MDF or particle board simply because it might be more abrasive and at the same time more consistent. I'll have to look around and see what's available locally. I sharpened the chisels so far up to 1500 grit and then touched them on a leather strop to finalize the edge. That's as sharp as I get my hand plane blades and they cut wispers off wood. When I took slices off a piece of paper I couldn't believe how easily it cut. Probably not as easy as the floating silk in the movie Bodyguard (which myth busters proved wouldn't work anyway).
     
  20. robo hippy

    robo hippy

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    One thing with MDF, other than being terribly dusty is that it is not consistent. The surface is more dense than the interior. I would guess that it is pressed in single sheets unlike standard plywood which can be stacked several (30 plus) high. The inside does not compress as much. I am not sure how much difference that would make.

    robo hippy
     

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