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  1. #1
    Join Date
    Nov 2019
    Location
    Melbourne
    Posts
    5

    Default Waldown 8sn series III spindle with JT6 taper

    Hi,

    I bought an old Waldown pedestal drill press 8SN Series III for restoration and put it in my workshop later.....

    This is my very first drill press.

    Few weeks ago, I pulled out a Jacobs #34 keyed chuck and
    I see a damaged thin brass sleeve inside taper hole....I have no idea...


    IMG_4329.jpgIMG_4332.jpgIMG_4330.jpg

    But now......I think that JT6 taper on spindle has been shaved off a bit on lathe and
    added a thin brass sleeve on it to hold the chuck together.......is that right?

    I wanted to add a new keyless chuck .......but first, what should I do? where can I get a new sleeve?
    or look for another spindle?

    Thanks
    - John

  2. #2
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,444

    Default

    Hi John,

    Welcome to the forum

    I've seen that trick done, using brass or copper shim to fix a damaged spindle taper. Very often the damage is just scoring and can be cleaned up with fine emery cloth. The drill chuck should push almost all the way on the taper. Screw the jaws fully back inside the body and using a block of hardwood between the chuck nose and the table press the chuck onto the taper. It should fit firmly in place without any shims.

    If it is loose at this point then you will need to replace the shim and go through the fitting operation again. The chuck should run true without any wobble. A wobble could indicate that the spindle might be bent.

    As far as a new chuck is concerned, there are at least two different tapers in common use, JT and BT ones. They are not interchangeable.
    Best Regards:
    Baron J.

  3. #3
    Join Date
    May 2011
    Location
    Murray Bridge S Aust.
    Age
    71
    Posts
    5,945

    Default

    Hi John welcome to a TOP FORUM, any chance of a pic of your spindle please?
    Your chuck should go back on without the extra shimming, that's why they are tapered. About the only thing that would prevent it seating, is if the taper itself is worn, or that it's too long for the chuck.
    Kryn
    To grow old is mandatory, growing up is optional.

  4. #4
    Join Date
    Oct 2011
    Location
    Norwood-ish, Adelaide
    Age
    59
    Posts
    6,542

    Default

    This table of Jacobs tapers is from littlemachineshop.com (just because it was the first to come up with on google)

    Taper Large End Small End Length Taper/
    Foot
    Taper/
    Inch
    Angle From Center
    #0 0.2500 0.2284 0.44 .5915 .0493 1.4117
    #1 0.3840 0.3334 0.66 .9251 .0771 2.2074
    #2 0.5590 0.4876 0.88 .9786 .0816 2.3350
    #2 Short 0.5488 0.4876 0.75 .9786 .0816 2.3350
    #3 0.8110 0.7461 1.22 .6390 .0532 1.5251
    #4 1.1240 1.0372 1.66 .6289 .0524 1.5009
    #5 1.4130 1.3161 1.88 .6201 .0517 1.4801
    #6 0.6760 0.6241 1.00 .6229 .0519 1.4868
    #33 0.6240 0.5605 1.00 .7619 .0635 1.8184
    As you can see, a JT6 and a JT33 are very close. I'm wondering whether the shim is there because the taper on the chuck is not the same as the taper on the spindle...
    Just a thought, as that shim should not be needed.

    Michael

  5. #5
    Join Date
    Aug 2008
    Location
    Charlestown NSW
    Age
    65
    Posts
    1,669

    Default

    A lot of chucks (good ones at least) have the taper size etched onto the body of the chuck somewhere. Usually near where the capacity is etched.

  6. #6
    Join Date
    Nov 2019
    Location
    Melbourne
    Posts
    5

    Default

    Thank you very much for replies

    I cannot find taper size marker on old #34 British-made Jacobs chuck.....without shim, it will drop like a stone......I can feel it very loosely......like a mil gap.

    I'll ask my brother to borrow a digital vernier caliper measurement from his work......to find out what size...... maybe reduce to JT33 at the machine shop and get a new 1-13mm keyless chuck with JT33....I don't know....I'll just wait for measurements.

    Jacobs Tapers.jpg

    Some pics of my spindle...............

    IMG_4336.jpgIMG_4337.jpgIMG_4338.jpgIMG_4339.jpgIMG_4340.jpgIMG_4341.jpgIMG_4342.jpgIMG_4345.jpg

    I'll look for another spindle with Morse taper.......it's nice to have that......

    drill_bits_MT2_shanks.jpg

    Thanks again
    - John

  7. #7
    Join Date
    May 2011
    Location
    Murray Bridge S Aust.
    Age
    71
    Posts
    5,945

    Default

    Thanks for the pics John, unfortunately that doesn't really help us determine the cause, as everything looks Mickey Mouse.
    Would it be possible to get pics of the inside taper of your chuck and any markings, please?
    Someone may recognise it or the problem.
    It could also be possible that you have a DIN238 series chuck? Or that you have the 33 chuck with a 6 arbor?
    https://uk.roehm.biz/fileadmin/produ.../DC0000321.PDF
    Kryn
    To grow old is mandatory, growing up is optional.

  8. #8
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,444

    Default

    Hi Guys,

    The number 34 Jacobs chuck was made with several sizes of arbour sockets. There should be a number after the 34 - xx that tells you what taper it is.
    Best Regards:
    Baron J.

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