TMX Scroll Chuck Variation
Close
Login to Your Account
Likes Likes:  0
Results 1 to 7 of 7
  1. #1
    Join Date
    Jun 2018
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    5
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default TMX Scroll Chuck Variation

    Wondering if anyone has had this issue before... I've got a 6" TMX, 6 Jaw, Scroll Chuck. I have it fixtured into a set-tru type back plate that allows me to dial in work pieces. The issue I've discovered is if I dial in a drill rod, remove it, and then reinstall it, it only returns to zero if I use the same bolt to operate scroll.

    So for example if I indicate when using bolt 1 to tighten.

    BOLT 1: TIR 0
    BOLT 2: TIR 0.004"
    BOLT 3: TIR 0.007"

    If I use Bolt 2 to tighten when dialing:
    BOLT 1: TIR 0.007"
    BOLT 2: TIR 0.000"
    BOLT 3: TIR 0.004"

    My guess is this is some sort of backlash issue? It's very repeatable. Has anyone dealt with this before? I know simple answer is always use same bolt for tightening.

  2. #2
    Join Date
    Mar 2005
    Location
    Northwest Indiana
    Posts
    4,060
    Post Thanks / Like
    Likes (Given)
    713
    Likes (Received)
    769

    Default

    Yes. Normal on a scroll chuck. Mark the relevant socket and use it. It usually isn't such a big difference, your chuck must be well used.

  3. #3
    Join Date
    Jun 2018
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    5
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default

    Thanks.

    It's barely a year old and I don't use it that much. Just started noticing it. So assume it's gotten worse recently for some reason.

  4. #4
    Join Date
    Feb 2006
    Country
    UNITED STATES
    State/Province
    Indiana
    Posts
    12,857
    Post Thanks / Like
    Likes (Given)
    668
    Likes (Received)
    3826

    Default

    Most of the chucks I use have only one key socket, so there is no such issue.

    But I think I have seen chucks with three key sockets where one was marked with "0." I suspect the 0 socket was the one that was tightened when the jaws were finish ground. It does not matter which socket is used to remove the work, of course.

    I have seen chucks with enough wear that the jaw gripping surfaces are not parallel when tight. That condition allows the work to wobble at random after tightening, so removing and installing work will result in random indicator readings.

    Larry

  5. #5
    Join Date
    Jun 2018
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    5
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default

    Larry,
    Thanks for input. Pretty sure this isn't a jaw wear issue. Since chuck is so new, and I haven't clamped anything tapered in it. I can grab a work piece that's sticking 8" out of chuck and apply pressure and nothing shifts. Also, results are very repeatable tightening the different sockets.

    Luke

  6. #6
    Join Date
    Jun 2018
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    5
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default

    Larry,

    You are correct. One of the sockets is marked "0".

  7. #7
    Join Date
    Sep 2014
    Country
    UNITED STATES
    State/Province
    Georgia
    Posts
    337
    Post Thanks / Like
    Likes (Given)
    256
    Likes (Received)
    125

    Default

    The scroll is fitted too loosely in the chuck body. Tightening each of the three sockets pushes the scroll off center in a different direction. You will always have to use the same socket that was used prior to truing.


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
  •