40/40 grind

Discussion in 'Newbie' started by Dave Fritz, Nov 8, 2016.

  1. john lucas

    john lucas

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    I learned that method from John Jordan and it's mostly used when you get a new tool and have to establish the wing shape you want. Grind the nose. Draw a line with a permanent marker to show you where to stop once you've ground it with the flute against the wheel. The grind the wings and then blend the wings into the nose.
     
  2. Kevin Campbell

    Kevin Campbell

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    Thanks for the info. I basically ground, as usua, only very little on the nose. After a few swings, it started to come back to its original shape, and profile. Then I put it on the other wheel, and sharpened it. I'm going to give the 40/40 grind a try, as soon as I get my nerve up..
     
  3. Jamie Straw

    Jamie Straw

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    Too funny. One of our veteran turners, who produces fabulous, fabulous stuff, took a workshop with ... either Batty or Tom Wirsing... anyways, since he'd been turning for 20 or 30 years, it just plain didn't work out for him. Too different from what his techniques have been all those years.:D
     
  4. Dave Fritz

    Dave Fritz

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    Interesting comment Jamie, at the Batty demo I attended an older man I know said he'd have to forget most of what he believed before. I doubt he did. When you reach a certain age it's hard to go back and start over.
     
  5. john lucas

    john lucas

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    At my classes it's the older gentleman who can't seem to grasp bevel rubbing or changing what they are doing. I will rotate the tool in their hands to show them how it cuts clean or with less chatter and as soon as I turn my back I can hear them digging into the wood again. The best student I ever had was a female Nurse. She listened to what I said and then did exactly that and was turning really nice pieces by the end of the class.
     
  6. Fadi Zeidan

    Fadi Zeidan

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    I believe this is a video of what Bill is describing. I was watching it couple of days ago and found it useful.

    http://thompsonlathetools.com/sharpening/
     
  7. Bill Boehme

    Bill Boehme Administrator Staff Member

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    Yep, that's it. It's good for quickly making a big change to the shape of the tool, but it also grinds away a lot of steel so only use it when absolutely necessary.

    Doug does a good job simplifying tool grinding to make it easy for beginners to see the how and why of sharpening. But, if you wish to grind to a different shape by using a different leg angle, tool protrusion length, and Wolverine V arm setting that's fine ... everything he says about how to grind still applies.
     
  8. hockenbery

    hockenbery AAW Advisor Staff Member

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    This method is the best way I have found to put wings on a new gouge that does not have them.
    It also is useful on particularly badly ground gouges.
    If you try grinding a wing with out jointing the top of the wing quite you will usually get very thin metal bit of metal sticking up on the top of the wing that bends over instead of grinding off. Jointing the top of the flut eliminates this problem and also gives you the target edge of flute to grind to.
     
  9. Jon Minerich

    Jon Minerich

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    A few days ago I posted a link to Stuart's full video that shows both hand grinding method and a discussion of "bottom gouges". It's on the main forum.
     
  10. WoO

    WoO

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  11. WoO

    WoO

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    I know I'm late to the party but haven't been on for awhile and only found this string while updating a handout I made on grinding angles. Regarding Stuart's 40/40 grind I have one more thing to add that hasn't been included in the string. The setting John Lucas described in his post is correct. I don't have the Wolverine Vari-grind with the notches, but I put the setting all the way forward (or back depending on your perspective) - see picture, which appears to be the same as using the last notch as John did. The one thing I have to add, is that Stuart was teaching in my shop last November and ground one of my gouges with his 40/40 grind. I then played around with several different sharpening jigs I have, by coloring the bevel of Stuart's grind with a magic marker, and then rotating the CBN grinder wheel by hand until I found a setting where it contacted the bevel on all areas, front and side. I was unable to replicate his grind on any other jig other than the Wolverine. I now use his grind on almost all of my bowl gouges. 40-40 Wolverine setting.jpg
     
  12. Jamie Straw

    Jamie Straw

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    Hi, Larry, looks like your reply didn't make the post, what were you going to say? As much time as you've spent with Stuart, I'm curious about any advice you might have on the 40/40 grind. Tom Wirsing reground 2 of my bowl gouges at the platter workshop, but they'll need re-sharpening, yesterday actually.:D
     

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