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  1. #1
    Join Date
    Aug 2019
    Location
    Revesby - Sydney Australia
    Age
    56
    Posts
    1,185

    Default Sharing QCTP tools between different lathes

    I have a Hercus 9, a Hafco AL336, and two compatible QCTPs;
    so I can use the same holders, and mostly 16mm tools, in each.

    Now, the lathes' centre heights are close, but not exact.
    (My measurements say Hercus 26.2mm, Hafco 31.5mm, above the compound slide)

    For a while I used a big washer on the Hafco, about 4.5mm thick,
    to lift the QCTP above the Hafco's compound slide.
    It made the tools nearly useable without adjustment, but not quite.
    (I am too lazy to keep adjusting the centre height)


    Last week, I found a little bit of odd scrap, about 6mm thick, and did some machining.
    But not the obvious washer shape!

    Mount the scrap on a mill,

    find a not totally blunt 12mm end mill:
    IMG_1438.jpg and start to mill a T slot nut profile.
    Relocate the clamps: IMG_1441.jpg and mill the back step.
    Locate the washer somewhere safe to drill: IMG_1444.jpg and centre the cutter in my badly machined step.
    Plunge: IMG_1445.jpg which, due to my badly milled steps,
    was not in the centre of the washer
    Found an 18mm drill, enlarged hole. no pic Tested in top of compound slide.
    Hole not centred perfectly -
    had to file one side a little.
    Time to try something new -

    surface grinding!
    no pic Spent at least an hour practicing,
    on the old 4.5mm thick washer.
    Wheel survived a few too wide,
    and too deep, grinds.
    Align step with a D.I.: IMG_1446.jpg so I can grind into the corners.
    A lick across the front,

    then the back,

    then the top:
    IMG_1447.jpg and 2 hours later I have some mirrors!
    Also did the tricky/dangerous part...

    grinding the flat top:
    no pic but I didn't use transfer blocks.

    I just magnetised the middle step,
    and did VERY shallow cuts.
    Test fit on the compound: IMG_1448.jpg
    and, IT FITS!!!! IMG_1449.jpg A satisfying tight fit -

    good end to the day.

    Time to go home.
    Day 2, align the QCTP: IMG_1454.jpg with the compound at an angle

    (here, 30° clockwise)
    and mark a centre: IMG_1459.jpg with a transfer punch
    in the QCTP location hole.
    Repeat at a few other angles: IMG_1461.jpg for some other common angles.
    Do some drilling and try to de-burr and have to use a file instead
    and voila: IMG_1463.jpg one scratched,

    but useable,

    QCTP location plate!




    So, some discussion is in order.


    Even though I have never used one, I like the idea of 4 way toolposts, that they have a detent* to align them (mainly for parting off). However, I think it is silly that they only align with the compound at 0/90/180°?

    I thought about mounting a 4way as a rear toolpost, but most lathes can't move the cross slide close enough to the operator for this to be useful?

    So, I frankensteined this solution. Which is just a prototype really, but I'll see how much time it saves me.





    (*) Speaking of detents, wouldn't it be nice if the compound had a detent or two to align at useful angles?
    Like a mitre saw?

    I set at 30° a lot - mainly so the compound clears the tailstock, but 0/45/90/135 and 60 would also be useful.

  2. #2
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,443

    Default

    Hi Nigel, Guys,

    Whilst I can see and understand what you have done and why !

    I got rid of my QCTP and my four way tool post in favour of making and using a "Norman Patent" tool post. I don't have or find any need for rotational indexing and certainly do not miss the expensive tool holders. I'm not into production or interested in making money like industry is. Commercial enterprises have to maximise profit so time is money to them.

    I'm sure that you have seen the pictures of both my front and rear Norman tool posts. They are not too difficult to make either. As far as tools are concerned the only insert tooling that I have are for threading, bar a 10 mm boring bar which doesn't get a lot of use. I don't have any problems with setting the tool height either, or need shims, which can be an issue when using HSS and grinding your own tool bits.

    As far as setting a parting blade square to the work is concerned, I just set it up against the face of the chuck. The fact that it is in the rear toolpost holder and upside down doesn't matter.

    Here is a link to mine !
    https://metalworkforums.com/f303/t20...orman+Toolpost

    HTH.
    Best Regards:
    Baron J.

  3. #3
    Join Date
    Nov 2007
    Location
    melbourne australia
    Posts
    3,228

    Default

    Nice work.

    Quote Originally Posted by nigelpearson View Post
    Even though I have never used one, I like the idea of 4 way toolposts, that they have a detent* to align them (mainly for parting off).
    Nah, I don't miss mine!
    Chris

  4. #4
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,443

    Default

    Quote Originally Posted by jack620 View Post
    Nice work.



    Nah, I don't miss mine!

    Hi Chris,

    Me neither !
    Best Regards:
    Baron J.

  5. #5
    Join Date
    Aug 2019
    Location
    Revesby - Sydney Australia
    Age
    56
    Posts
    1,185

    Default

    Quote Originally Posted by BaronJ View Post
    I'm not into production or interested in making money like industry is. Commercial enterprises have to maximise profit so time is money to them.

    I mostly agree, but none of us are getting any younger

    e.g. A lathe doesn't need quick change tooling, but if it means I can get two odd jobs out of the way before lunch instead of one, then I can go for a longer lunch!






    However, there is something nice about a simple lathe setup.
    Every time I see a turret attachment,
    half of me thinks "that would be so much faster,"
    and the other half thinks "wow that thing is ugly, and must really get in the way."



    A rear toolpost is tempting, but part of me thinks cross slides don't wind out enough to use one?

    (i.e. for decent swing between the two toolposts, they need decent spacing/separation,
    so slide needs to be all the way out on the regular post so the rear post gets close to centreline)

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