Upgrading my Harrison L5 with a Dixon type toolpost

  1. mm289 Member

    Messages:
    503
    Dover, Kent
    Another Christmas hols project:clapping:. Bought a Dixon type QCTP off @HughF beginning of the year which was in great nick with lots of toolholders but never got round to fitting it....until last weekend:laughing:

    This is the original toolpost.
    2019-12-24 21.16.27 (Medium).jpg

    Mounts on a rotating cuff that is pegged into the retaining post/bolt
    2019-12-24 21.16.52 (Medium).jpg

    Thats great apart from the Dixon type has a larger retaining bolt which has a square dovetail/slide fitting into the compound rather than the original round/pressed fitting
    2019-12-24 21.17.17 (Medium).jpg

    Machining the underside of the compound to take the new post seemed like overkill so seemed like the pragmatic approach was to sleeve the new mount to snug up onto the original post.

    As it happened I had sorted out my steel stock about 4 weeks ago, dragged it out of storage (on the floor:whistle:) and cut it down so it would fit into a corner of the machine shop I could actually get too.
    2019-12-24 21.20.29 (Medium).jpg

    And that meant I could actually find some bright steel rod which was a pretty much perfect diameter for the inside of the new toolpost holder:laughing:
    2019-12-24 21.20.20 (Medium).jpg

    So drilled and reamed out the internal bore so it was a nice snug fit over the retaining bolt
    2019-12-24 21.21.06 (Medium).jpg

    and then an easy press fit into the toolpost itself.
    2019-12-24 21.20.50 (Medium).jpg
    2019-12-24 21.21.34 (Medium).jpg

    Then could re-assemble using the clamping washer from the new toolpost which is bevelled to centre the toolpost on the bolt and the original tool post handle.
    2019-12-24 21.22.13 (Medium).jpg

    Now I just need to find enough uses for all the holders :clapping:

    2019-12-24 21.22.18 (Medium).jpg

    Seems to clamp down and hold really nicely and now means I can set the centre height accurately for each tool/holder and swap around quickly.

    This was my own theory on how to solve the problem, so just checking with you experienced machinists - any issues with taking this approach to fitting the new QCTP?

    Cheers,

    Paul.
     
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  2. Hood

    Hood Forum Supporter

    Messages:
    9,603
    Location:
    Carnoustie, Scotland
    You can never have too many holders :)
     
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  3. Hood

    Hood Forum Supporter

    Messages:
    9,603
    Location:
    Carnoustie, Scotland
    Oh and don't see any issues with doing what you did, I did similar on one lathe I had and it was fine.
     
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  4. Hopefuldave Intergalactic pot-mender

    Messages:
    1,012
    Location:
    The Shed of Danger, surrey, England
    Definitely need more holders... I'm up to a baker's dozen and want more!

    The sleeve is a good way to do it, leaves the option of putting the original post back on which redrilling the topside doesn't - I made a new humongous tee nut as my topslide has a Suitable Slot. Went well until I got to tapping it M16, and couldn't get the thread to start - which idiot had picked up a lefthand tap...?

    Where the hell did that come from?

    Dave H. (the other one)
     
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  5. Pete.

    Pete. Member

    Messages:
    8,551
    Location:
    Kent, UK
    Blue the bottom of the post and the top of the compound. Make sure you don't have a raised bit in the middle or it'll turn under load. Apart from that set the tool post square to the chuck and get used to using it like that, should be easy with all the holders you have.
     
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  6. HughF

    HughF Member

    Messages:
    5,469
    Location:
    Work: Dorchester, Workshop: Corfe Castle, Wife's place: Frome
    Nice job, hope you get on with the toolpost better than I did...
     
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