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Thread: Bowl Turning - Recess in the bottom to fit over Nova chuck

  1. #1
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    Feb 2017
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    Bowl Turning - Recess in the bottom to fit over Nova chuck

    I am relatively new to turning. I have seen a lot of responses on this and other forums concerning how to get the dovetail in the recess on a bowl bottom to fit over the dovetail on the Nova chuck (in this case a Nova G3) but cannot find any videos showing this. Given that I learn better seeing sometimes than by description it would be helpful to find a video reference of this operation.

    I have tried a parting tool and am now trying a flat skew, but end up with catches and have not been very successful. I have seen the Nova Dovetail tool and may just buy that but, before I do I'd really like to be able to do it with the 3/4" skew I bought. Any suggestions on videos or a site that has more pictures? I think my biggest problem is how I'm presenting the skew to the bowl bottom, which is why it's catching. Thanks.

  2. Your skew should be resting on the toolrest with the flat side on the rest, and the long point towards you. It should be in scraping mode, with light contact with the wood.....what we refer to as a negative rake position. Make the recess a little at a time with forward movement into the wood, taking a little bigger circle until you are at the diameter you need for the chuck jaws. You should be cutting at a hair above the center and not below it.

    Sorry, I do not know of any videos, but this is a simple thing to do.
    Remember, in a moments time, everything can change!

    Vision - not just seeing what is, but seeing what can be!




  3. #3
    https://www.youtube.com/watch?v=hSpLuWsVuYE

    https://www.youtube.com/watch?v=7ZKRlMNC5mc

    Search YouTube Randy and you'll find quite a few demonstrations.

  4. #4

  5. #5
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    Roger Chandler,

    I'm sure it is a simple thing to do. I do have a couple of questions about your explanation. . .

    1. When you say the skew should have the "long point towards you". I'm not sure what that means.
    2. What is the "scraping mode"? Negative rake position?

    So, push the long point into the wood up to the outer edge of the diameter of the circle you need cut. To get the dovetail shape (angled sides that fit over the G3 chuck), do you just move the skew sideways till you reach the correct angel?

  6. #6
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    Jan 2004
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    What Roger means is this. Your tool rest is perpendicular to the lathe bed and parallel to the bottom of the bowl blank. You hold your skew parallel to the lathe bed with the long point closest to you so you are cutting as you draw the tool towards you on the tool rest.

    I had to stop and think about it too.

    When you scrape using a tool, typically you want the scraper either absolutely horizontal or tilted slightly down referring to the working end. In other words, the handle slightly higher than the working end of the tool.

    Watch Mike Peace's video. He shows it quite well, IMO.
    Ken

    So much to learn, so little time.....

  7. #7
    Randy,

    Reed's video is very helpful. I basically follow the procedure he describes early in the video. I cut mortises for scroll chuck mounts with a large Forstner bit with diameter that is just a bit larger than my #2 jaws, closed.

    If I was going to turn the mortise on my lathe I would rough it out with a parting tool (cut many circles) and clean it up with a bedan tool. I don't think that you need to fuss about the dovetail angle. My jaws are straight so I cut a straight-sided mortise and it holds well.

    Doug

  8. I was not aware of Reed's youtube video on this, but I had previously seen Mike Peace's video. Sorry I failed to recall that, and thanks to those who gave the links to them. Thanks Ken for elaborating on my comments....sometimes a thought is clear to the commenter, but not clear to the reader.
    Remember, in a moments time, everything can change!

    Vision - not just seeing what is, but seeing what can be!




  9. #9
    Join Date
    Feb 2007
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    Inver Grove Heights, MN
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    I cut the recess with a bedan or with a 2 1/8 inch forsner bit. Normally I do not cut the dovetail in soft or medium density wood. When I do cut the dovetail I use a skew as described by others. Basically I find it easier to cut the recess and then add the dovetail if I think it is required.

  10. #10
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    Here is a video by Bob Hamilton that shows a nice way of making a recess, you can skip right to about the 7 minute mark, but the whole video is well worth watching, Bob has a nice and easy going way of showing how he does it.

    https://www.youtube.com/watch?v=uVjLGHVHF50

    I myself use the recess almost exclusively, and have for many years, I just use a scraper with a curved end that becomes a point (see picture) and push that in going in steps till the recess is large and deep enough, I always use a straight walled recess, and make sure it is cut nice and clean.

    underside scrapers.jpg

    The jaws grip right at the bottom, you can see that in this picture.

    Recess gripped inside.jpg
    Have fun and take care

  11. #11
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    Thanks for all the responses. I read them all and I ended up getting very close to the desired final product this evening when I had a little bit of time. I just need a little more practice to get it perfect. I did use the skew and, although I did not first understand, I figured out what the intent was when I got down to my lathe.

    After watching Reed's video, I think using the dovetail tool looks a lot easier and more reliable to create a dovetailed recess, especially for a beginner like me. I know Nova makes a dovetail turning tool that cuts at the angle of their chucks.

    Anyway, thanks again. The video references were very helpful and your information very useful.

  12. #12
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    I did purchase the dovetail chisel and find that, after a couple of tries I think it was a great choice to quickly get a recess in the bottom of the bowl to fit my chuck. Question about sharpening this tool . . . I have honed the flat side of the tool with my regular stones using the 800 and 1200 diamond and then my 4000 and 8000 waterstones. I guess the cutting is a little better, but I am wondering if there is something else I can do to sharpen it without disturbing the dovetail angle? Any suggestions or is honing the back flat side it?

  13. #13
    Randy,
    We recently had a demo by the owner of the local Woodcraft Store. When he got to his dove tail scraper, he told how it was 3 years old, and he only honed the top, which was very shiny. I had to stop and think because I had tried that before, but didn't do it any more. So, back in the shop, I was turning some madrone (cuts like green pear wood) and the honed top did a fairly good job, but any thing does a good job in madrone. I was turning some big leaf maple, which tends to be a bit stringy, and it didn't do a good job on the BLM. I put a burr on it, and it did a much better job. The dove tail tool is a scraper, and scrapers, on all but the hardest woods, cut better with a burr. So, hone off the old burr, or burnish it down. Then hone, grind, or burnish a new burr back on, by touching up the bevel, not the top. I have found 220 hones raise a better roughing type burr than a 600 grit hone. That is more suitable for fine finish cuts..

    robo hippy

  14. #14
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    What chuck has square jaws on the outside?
    Retired - when every day is Saturday (unless it's Sunday).

  15. #15
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    Quote Originally Posted by Thom Sturgill View Post
    What chuck has square jaws on the outside?
    No dovetail on the standart Oneway profiled jaws, and they hold best on straight tenon or recess.

    Oneway Profiled_Jaws.jpg Chucking spec's.jpg
    Have fun and take care

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