Union 3 jaw chuck disassembly
Close
Login to Your Account
Results 1 to 14 of 14
  1. #1
    Join Date
    May 2009
    Country
    UNITED STATES
    State/Province
    Washington
    Posts
    208
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    87

    Default Union 3 jaw chuck disassembly

    I`ve got all the bolts and the jaws out but I cannot get any further.
    Looks like the plate in the back is a separate piece.
    The turning screws won`t budge out either?
    Attached Thumbnails Attached Thumbnails kimg0852.jpg   kimg0853.jpg   kimg0854.jpg  

  2. #2
    Join Date
    Jul 2009
    Location
    Munster, In. USA
    Posts
    2,322
    Post Thanks / Like
    Likes (Given)
    471
    Likes (Received)
    701

    Default

    Expect an interference fit and there may be locating pins to align the two sections.
    First...match mark the two sections at the split line.
    Set on edge and smack with a big dead blow soft face hammer against the back is sometimes enough to start separation.
    Think of billiards/pool.
    Use a bit of cardboard or carpet to set the chuck on, minimize scratches.
    One can also insert the chuck key into the pinion and tap towards the back of the chuck so the pinion is not driven into the gear side of the scroll.
    If an opening is started banding or shim stock will hold the split open. Do not use a screwdriver or such to pry the finished surfaces apart.
    John

  3. #3
    Join Date
    May 2009
    Country
    UNITED STATES
    State/Province
    Washington
    Posts
    208
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    87

    Default

    Ok ta.
    What about removing the screws in a 4 jaw chuck?

  4. #4
    Join Date
    Apr 2006
    Location
    Manchester, England
    Posts
    8,258
    Post Thanks / Like
    Likes (Given)
    1201
    Likes (Received)
    5232

    Default

    I used to stand the chuck on it's outside diameter then just give the scroll a sharp tap in all three places with an aluminium drift or an hard piece of wooden dowel. That'll normally separate the two halves. Mark them up first though if the two halves haven't already been marked. The " turning screws " are normally held in place by a fluted dowel. You need to split the chuck to access these dowels. They are drilled and tapped on the end to aid removal. You can remove the dowels by putting a small screw into the dowel and pulling on the screw. Failing that it's slide hammer time.

    As for four jaw chucks - remove the jaws first. When you've removed all four jaws if you look at the back you'll normally see the rear face of the 4 retaining forks. On a good chuck they'll be held in place with small screws. Remove the screws. Again on a good chuck the retaining forks will be drilled and tapped for removal. If you have a slide hammer you can remove them easily. Failing that make a small bridge and a strong back and wind the forks out with a screw. Failing all that and if the fork isn't drilled and tapped you may tap the fork out with a small drift from the front. Sometimes it's possible to drill and tap the fork but normally they are hardened so then it's almost impossible.
    The jaw adjusting scroll screws should slide out easily after that.

    You can get other issues IE the jaws won't slide all the way out because the outside of the chuck has been damaged. Ditto the jaw adjusting scroll screws won't come all the way out either. There are techniques to overcome these problems but we'll cross that bridge if we come to it.

    Regards Tyrone.

  5. Likes jhruska liked this post
  6. #5
    Join Date
    Jul 2009
    Location
    Munster, In. USA
    Posts
    2,322
    Post Thanks / Like
    Likes (Given)
    471
    Likes (Received)
    701

    Default

    The Union 6 inch #123 - K exposed!

    union-6-inch-chuck.jpg

  7. Likes Tyrone Shoelaces liked this post
  8. #6
    Join Date
    May 2009
    Country
    UNITED STATES
    State/Province
    Washington
    Posts
    208
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    87

    Default

    That helps a lot . I got the 4 jaw apart so that's getting cleaned.
    I`ll prolly just soak the 3 jaw in gas and clean it up that way.
    Don`t plan on using it as I intend to start off using the 4 jaw and learn that way.
    I`ll see how brave I feel once it`s clean.

  9. #7
    Join Date
    Jul 2004
    Location
    Houston, TX USA
    Posts
    29,769
    Post Thanks / Like

    Default

    There are 3 jaws split differently - on those the pinions have to come out first

  10. #8
    Join Date
    May 2009
    Country
    UNITED STATES
    State/Province
    Washington
    Posts
    208
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    87

    Default

    Well I grew a set and got it apart , not to bad in there should clean up nice.
    The question is to grease of not to grease? It does have an oil port so im thinking oil better than grease?

  11. #9
    Join Date
    Nov 2008
    Location
    Madera county california usa
    Posts
    2,421
    Post Thanks / Like
    Likes (Given)
    21
    Likes (Received)
    602

    Default

    Good you hot it open.

    We usually back out the screws that hold it together a few turns then smack them with mallet or handy 2x4 and it drives the Chuck parts apart and retains them by the screws still being in place.

    Sent from my SAMSUNG-SM-G930A using Tapatalk

  12. Likes JST liked this post
  13. #10
    Join Date
    May 2009
    Country
    UNITED STATES
    State/Province
    Washington
    Posts
    208
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    87

    Default

    That's exactly what I did.

  14. #11
    Join Date
    Apr 2006
    Location
    Manchester, England
    Posts
    8,258
    Post Thanks / Like
    Likes (Given)
    1201
    Likes (Received)
    5232

    Default

    Thanks for that guys. I've never seen a three jaw chuck that splits more or less in half like that one. I've got to say that you don't come across 6" chucks in heavy engineering very often. Usually chucks have the main body and what is more or less a backing plate. Having said that it's great that here's always something new to learn on this site.

    Regards Tyrone.

  15. #12
    Join Date
    Apr 2006
    Location
    Manchester, England
    Posts
    8,258
    Post Thanks / Like
    Likes (Given)
    1201
    Likes (Received)
    5232

    Default

    Quote Originally Posted by jabberwoki View Post
    That helps a lot . I got the 4 jaw apart so that's getting cleaned.
    I`ll prolly just soak the 3 jaw in gas and clean it up that way.a
    Don`t plan on using it as I intend to start off using the 4 jaw and learn that way.
    I`ll see how brave I feel once it`s clean.
    Mastering four jaw work isn't easy at first but it's worth the effort.

    Regards Tyrone.

  16. #13
    Join Date
    Jul 2009
    Location
    Munster, In. USA
    Posts
    2,322
    Post Thanks / Like
    Likes (Given)
    471
    Likes (Received)
    701

    Default

    Quote Originally Posted by johnoder View Post
    There are 3 jaws split differently - on those the pinions have to come out first
    Here is the Union No. 81 chuck that is just the opposite of what Johnoder mentioned. The pinions are loaded before the back plate is set in place. Pinions are 'loose' as there are no half-washers to hold them in place.
    This 6 inch chuck has taller jaws with a double slot and it uses the identical scroll of the #123 - K.
    The #81 chuck is likely older as the face of the chuck is marked CLASS S a turn of the century ordering code.
    This is a one piece body and the back plate drops into a counterbore in the back of the chuck.
    union-6-inch-no-81-extended-depth-chuck.jpgunion-no-81-chuck.jpg
    John

  17. #14
    Join Date
    May 2009
    Country
    UNITED STATES
    State/Province
    Washington
    Posts
    208
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    87

    Default

    All done with the 3 jaw.
    Thanks for all the help.
    Attached Thumbnails Attached Thumbnails kimg0860.jpg   kimg0861.jpg  

  18. Likes jhruska liked this post

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •