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Thread: Cutting v grooves with Skew chisel

  1. #1
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    Cutting v grooves with Skew chisel

    I am having a devil of a time using the devil's can-opener.

    I am trying to cut v grooves on chair legs. Once they get deeper than 1mm, my point catches the edge and skates down the leg. I have watched a bunch of videos and thought I understood the physics of this cut. But I cannot for the life of me tame this cut.

    Below are my practice cuts.

    It feels like I am catching the top corner, where the notch begins. The only way I can mitigate this is to approach the notch with my tool 90 degrees to the work. This has the effect of making the notch more vertically shouldered instead of my desired 45 degrees.

    How do YOU do it? Any references welcome. I have already watched the Batty and Lacer videos online.
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    Last edited by Prashun Patel; 10-03-2019 at 10:10 AM.

  2. #2
    There is an Alan Batty video up on You Tube. One of the best ever. Look it up.

    robo hippy

  3. My approach is as follows:
    For the right side of the V, the skew should be coming in from the right (handle to the right of center). In addition, rotate the handle of the skew slightly clockwise so that as soon as the point begins the cut, the bevel on the right side of the skew will be supported by the right side of the V. Do the opposite for the left side; handle to the left of center, and a slight counter clockwise turn of the handle.

  4. First off....are you using the long point of the skew, and not the short point? If so, you have to get the angle and lift the handle to make the cut go into the valley of the V groove. A strong grip, not super tight helps control the cut as well.
    Last edited by Roger Chandler; 10-03-2019 at 6:29 PM.
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  5. #5
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    Thanks for the tips

    I think I am starting to get it.

    Yes, Roger, thanks, I am using the long point.

    The trick was setting my rest a little lower and then (as Roger said) lifting the tool into the cut. I was focusing too much on trying to keep bevel contact near the tip. In fact, that takes care of itself if you just think of it more as a series of parting cuts just approached from different angles.

    I can still make my cuts cleaner, but I'm not catching anymore. Thanks for the help.

    By the way, I am making Curtis Buchanan's Democratic chair. It is a fascinating and inspiring project. It really makes many aspects of Windsor chair making and green woodworking quite approachable. Parts are red oak; parts are (I think) white oak from our yard.
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    Last edited by Prashun Patel; 10-03-2019 at 10:27 PM.

  6. #6
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    It's difficult to know what to suggest without watching what you are doing. 5 minutes with an experienced turner would be valuable.

    For me the key to perfect v-grooves is positioning the skew so the edge and bevel on one side is alinged exactly with the angle of that side of the v-groove, or in actuality, the angle I want the side to be. For a deep v-groove I often sight down the bevel to align it. Every cut will widen the v a tiny bit so touch the point to fresh wood a tiny bit away from the last cut on that side. Then, as I lift the handle and start the plunge cut, I adjust the alignment the slightest bit so there is the tiniest clearance angle between the tool edge and the cut in progress. This clearance angle should be visible when sighting down the edge as the cut gets deeper.

    If the edge is aligned exactly with that side of the newly cut v without any clearance then a catch is likely. (The catch happens instantly when the outermost "corner" of the v contacts the cutting edge of the skew.) Plunge to a bit deeper than the last cut. I usually alternate sides as the v deepens, first cutting a thin slice from one side then the other, meeting exactly in the middle for a clean v. Never try to twist the tool to pry out swarf at the bottom of the groove, tempting at first. Instead, make slightly deeper cuts from alternating sides to cut the swarf away cleanly.

    For a deep v-groove, the path of the point in the wood if viewed from the side should describe a curve with the point spiraling toward the axis. The identical cut is used when cutting a short taper such as a shallow cone, or whem facing off a cylinder for a flat end. Darlow has a great illustration of this in his book "Fundamentals of Woodturning", a must-read in my opinion.

    I learned v-groove technique from either Darlow's or Raffan's book "Turning Wood", can't remember and I'm not home now to check.

    For teaching the shew I made a huge wooden skew from a piece of wood about 2x3" and illustrate the clearance needed using a deep v-groove I cut in a 3" cylinder. With the big groove it's easier ot see the angles and clearance needed.

    After a little practice with the right clearance you should never get another catch.

    JKJ

  7. #7
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    Thanks John. I figured it out. I was starting with the handle too high. Dropping the rest a few mm forced me to drop the handle of the skew and lift up into the cut. Of course, the bevel needs to clear that corner as the cut peels the groove wider, but I find that part intuitive. Raffan has a video about wood catches that helped me a great deal. The skew is a really wonderful tool. It really forces the user to understand the basics of how any lathe tool interacts with a spinning object. My skew practice has even improved my gouge use. I wish I had forced myself to study this years ago.

    Sharpening the skew is also so simple and intuitive - even easy to hone.

    I do think I need to spend some time with experienced turners. One of these days I'll make it out to one of the 3 great clubs in my area.

  8. #8
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    Quote Originally Posted by Prashun Patel View Post
    ...The skew is a really wonderful tool. It really forces the user to understand the basics of how any lathe tool interacts with a spinning object. My skew practice has even improved my gouge use. I wish I had forced myself to study this years ago....
    I'm sure I've mentioned this before but I start new turners on the skew. The skew is the very first tool in their hands and we learn planing cuts then v-grooves before picking up any gouge, even a spindle roughing gouge.

    I've never had a student get a catch. Several have said later the skew was their favorite tool, a lot easier than the spindle gouge! (Also, we never move to face turning (bowls) until we get some quality time on spindle turning.)

    JKJ

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