Thoughts on a Bison chuck for my SB9
Close
Login to Your Account
Likes Likes:  0
Results 1 to 11 of 11
  1. #1
    Join Date
    Oct 2020
    Country
    UNITED STATES
    State/Province
    Wisconsin
    Posts
    42
    Post Thanks / Like
    Likes (Given)
    4
    Likes (Received)
    9

    Default Thoughts on a Bison chuck for my SB9

    Can you guys share your thoughts on a Bison 4-jaw self-centering chuck (3675-8) from my SB9C? Could I expect it to be more accurate and useful than my 5-inch Cushman 3-jaw? Should I pass on the Bison and wait for a four jaw independent chuck? Is the 8-inch Bison too big for a SB9?

    THanks a lot!

  2. #2
    Join Date
    Feb 2016
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    1,823
    Post Thanks / Like
    Likes (Given)
    1251
    Likes (Received)
    682

    Default

    I don't know much about a self centering chuck. Love a 4 jaw independent chuck over a 3 jaw.

    8 inch is a bit big for yours, even though you could swing it. But if it was your main every day chuck, its a bit heavy and would add stress to spindle bearings. Probably a 5 inch is about right, if spindle hole is the same size or smaller than chuck hole.

  3. #3
    Join Date
    Jun 2013
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    850
    Post Thanks / Like
    Likes (Given)
    585
    Likes (Received)
    453

    Default

    Bison is very high quality, but not cheap. If I had the opportunity to get one, I would hold out for independent jaws at 6" dia.

  4. #4
    Join Date
    Feb 2011
    Location
    BFE Nevada/San Marcos Tx
    Posts
    2,813
    Post Thanks / Like
    Likes (Given)
    2891
    Likes (Received)
    1790

    Default

    Quote Originally Posted by bug_hunter View Post
    Can you guys share your thoughts on a Bison 4-jaw self-centering chuck (3675-8) from my SB9C? Could I expect it to be more accurate and useful than my 5-inch Cushman 3-jaw? Should I pass on the Bison and wait for a four jaw independent chuck? Is the 8-inch Bison too big for a SB9?

    THanks a lot!
    I would not expect it to be any more accurate than a 3 jaw scroll, it is the nature of the beast. If you want accuracy get a 4 jaw independent or a collet system. A 3 jaw is great in the right applications, where repetitive accuracy is not needed.

  5. #5
    Join Date
    Jan 2013
    Location
    NE Ohio, USA
    Posts
    112
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    21

    Default

    Quote Originally Posted by bug_hunter View Post
    Can you guys share your thoughts on a Bison 4-jaw self-centering chuck (3675-8) from my SB9C? Could I expect it to be more accurate and useful than my 5-inch Cushman 3-jaw? Should I pass on the Bison and wait for a four jaw independent chuck? Is the 8-inch Bison too big for a SB9?

    THanks a lot!
    Bug, pass on the 8" Bison. That's way too big for a SB9. Just pick up a nice used (or new) 5 or 6" 4-jaw chuck. I would bet at minimum, most SB9 owners (me included) have a 5" 3-jaw scroll AND a 6" 4-jaw independent. Obviously, you will have to "dial-in" your work when using the independent chuck, but it sounds like you are looking for better accuracy than a typical 3-jaw scroll chuck will deliver anyway. On my 3-jaw, the run-out is about .0015" give-or-take TIR. Sometimes more, sometimes less depending on the diameter of the work. My 4-jaw is a Cushman, probably as old as the lathe (1940ish) and quite possibly purchased WITH it. It still works quite well. I doubt if it is even possible to wear one out if used with decent care/finesse.

  6. #6
    Join Date
    Oct 2020
    Country
    UNITED STATES
    State/Province
    Wisconsin
    Posts
    42
    Post Thanks / Like
    Likes (Given)
    4
    Likes (Received)
    9

    Default

    Thanks a lot guys.

    I'll pass on the 4-jaw scroll and hold out for a 4-jaw independent in a little more manageable size.


  7. #7
    Join Date
    Jul 2020
    Country
    UNITED STATES
    State/Province
    Wisconsin
    Posts
    57
    Post Thanks / Like
    Likes (Given)
    4
    Likes (Received)
    24

    Default

    A good move passing on the larger diameter chuck.

    Yes the machine can spin something 8" diameter. But consider if the chuck will clear the saddle? Then opening the jaws even slightly you'll clobber the saddle or the ways. At that point yer gonna be mad at yourself for buying it.

    I have a sb9 and am bantering the idea of a 5 inch 6 jaw set tru around my mind. Being cheap has the approach avoidance conflict conundrum running around in my brain and has held me back on pulling the trigger on the purchase. The OEM 3 jaw usually provides .003 runout which isn't bad but,, well you know how it goes...

  8. #8
    Join Date
    Dec 2008
    Location
    princeton b.c.
    Posts
    300
    Post Thanks / Like
    Likes (Given)
    575
    Likes (Received)
    94

    Default

    I fully agree that chuck would have been much too large. And since you've already decided against it this will only be useful for general information. After buying a smaller and only 80 mm in diameter Austrian made Emco 4 jaw scroll chuck when they were still available, the idea of that design of chuck works a lot better on paper than in real life. And I'd bet mine cost me at the time pretty close to what that Bison 4 jaw would have cost. Ok it is pretty good with under .0015" at any size I've checked it at, but that run out is still there and can't be adjusted out like an independent chuck can unless you shim the part to remove it. To do that you've still got to indicate to find the high side first. Secondly and for holding square shafting, I now think there actually meant as more of a manual lathe second operation work holding option. Any square work has to be very accurate and equal in size or the chuck can't properly grip on each flat side of the part. Most square shafting isn't made close enough unless it's machined to size first.For myself and in hind sight it was more of a waste of money than a good choice. You can do a hell of a lot of indicating of parts in a 4 jaw independent even on square parts before one of these chucks start to make sense. They will of course hold round shafts more securely, but an independent will also do that just as well. In most home shops there probably more of a convenience than anything else even when they are the correct size for the lathe.

  9. #9
    Join Date
    Oct 2020
    Country
    UNITED STATES
    State/Province
    Wisconsin
    Posts
    42
    Post Thanks / Like
    Likes (Given)
    4
    Likes (Received)
    9

    Default

    It helps a lot when you get consistent advice from those who have the knowledge.

    I appreciate all the insight, and help.

    Hope everyone has a great week.

  10. #10
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    19,381
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    11776

    Default

    Quote Originally Posted by bug_hunter View Post
    Thanks a lot guys.

    I'll pass on the 4-jaw scroll and hold out for a 4-jaw independent in a little more manageable size.

    Even a badly, BADLY worn 4-J indy is adjusted by YOU, so no NEED to "hold out".
    Get one. Even a San Ou is better than naked air. Get a better one later.

    I like to have pairs. My SCA's actual ARE "twins". One with jaws reversed. Pays off.

    Bison-now-also-Toolmex is it? Is only a medium-grade. Value-for-money, but hardly magical. Bison seems spendy?

    https://www.mscdirect.com/product/details/16042772

    Top jaws extra. Backplate extra.



    A Fuerda-Gator guy was ex-Bison. Hell-bent on beating them. His forged-steel 6-jaw says he's seriously competitive at that.

    My LIGHTEST 6" is a Forged-steel Bison. The heaviest 6" is actually a Yuasa.

    A "native" spindle back or backplate for SB 9 & 10 are VERY common on Cushman, Skinner, Horton, Union, "South Bend", and Atlas chucks, now-and-then also the right decent Pratt-Burnerd.

    I did say "get one"? No such animal as a "useless" 4-J indy.
    Some are just BETTER than others!


  11. #11
    Join Date
    Oct 2020
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    32
    Post Thanks / Like
    Likes (Given)
    15
    Likes (Received)
    9

    Default

    I needed a new chuck for my south bend 9a. I haven't even used the lathe (or a lathe for that matter). I bought a 6" Bison independent 4 jaw chuck and semi-finished back plate from Small tools inc for $681.04 after tax and shipping.


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
  •