Lathe Chuck Adapter Plate
Close
Login to Your Account
Likes Likes:  0
Results 1 to 4 of 4
  1. #1
    Join Date
    Dec 2016
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    347
    Post Thanks / Like
    Likes (Given)
    6
    Likes (Received)
    143

    Default Lathe Chuck Adapter Plate

    According to the brochure, my 1930s Reed Prentice 14 x 30 was only sold with a faceplate and drive plate (no chuck). Whether this is true or not is a bit irrelevant because when i bought it that's all she had. The spindle is a simple acme 4 tpi spindle with 5MT internal taper.

    I bought a new 10 inch 4 jaw with an A2-8 spindle mount and a 10" OD x 3" chunk of dura bar to machine an adapter plate. I've pretty much got my process all worked out and am just about ready to start.

    However, when you look at the back of the chuck there is a fairly large counter bored hole (shown in the attached pic at about the 8 o'clock position. Does anyone know the purpose of this hole? Is it simply to balance the chuck or is it there for a mating drive pin in the adapter plate?

    A second question is why would they not have sold this machine with a chuck back in the day?

    Mark
    imag1268.jpg

  2. #2
    Join Date
    Jul 2004
    Location
    Houston, TX USA
    Posts
    28,867
    Post Thanks / Like

    Default

    A type spindle nose flanges have a drive "dowel" or "button" - that fits in the recess - for the purpose of not loading attaching bolts in shear

    A second question is why would they not have sold this machine with a chuck back in the day?
    Parsimonious Yankees?
    Last edited by johnoder; 04-13-2019 at 04:03 PM.

  3. #3
    Join Date
    Apr 2004
    Location
    Shandaken, NY, USA
    Posts
    4,131
    Post Thanks / Like
    Likes (Given)
    1029
    Likes (Received)
    6378

    Default

    Lathes were sold without chucks. Preferences in chucks varied with the buyers of the lathes. Taking the mindset of the era and of the people manufacturing as well as buying the lathes, we were not dealing with home shop machinists. A customer in a position to, and having need of, an engine lathe would have machinists or toolmakers who would take care of machining and fitting backplates to chucks on an as-needed basis.

    A customer might order a lathe as a new machine tool and order chucks supplied with it. This would be between the customer and the manufacturer's agent, who would contact the factory to determine if a mounted chuck could be supplied. Some lathe manufacturers did supply semi-machined backplates for threaded spindle noses, but again, the choice of chuck and its mounting were up to the customer. Some customers might already own several of lathes of like manufacture and having the same spindle nose thread as the new machine they were ordering. This meant they already had mounted chucks and faceplates in their shop, which likely eliminated their need to buy any additional chucks or faceplates.

    Case in point is my 13" LeBlond roundhead Regal lathe. It came with a mounted 3 jaw and mounted 4 jaw chuck. The 4 jaw chuck looked a lot older than the lathe by its design and markings on it. LeBlond used the same threaded spindle nose for some of their earlier cone-drive lathes. My lathe was shipped in 1943, right in the midst of WWII. Chances are getting a new lathe chuck was going to take some having a priority, so the original owner of my lathe made use of a 4 jaw chuck from an older LeBlond lathe that they had.

    The smaller, lighter lathes such as South Bend, Logan, and Sheldon offered chucks mounted on backplates, ready to use, as an accessories. A "drive plate" is usually a small plain faceplate with a single slot for the "tail" of lathe dogs. If you went to an old South Bend catalog and looked at the standard equipment furnished with their lathes, you'd find it was minimal at best. The 9" and 10" lathes were furnished with live and dead centers, a drive plate, one lathe dog, wrenches needed for the toolpost and carriage locking screw, a few other small items and a copy of "How to Run a Lathe". Chucks, along with the motor to drive the lathe, were up to the customer. The customer could buy the chucks and motor and motor controls from South Bend, or come up with these items on their own.

    It has been said that the screw cutting lathe is "the mother of all machine tools" because it is capable of making most of its own parts. This rings true in the case of chuck back plates. On lathes with threaded spindle noses, the different manufacturers had so many different spindle nose threads. Back "in the day", getting a backplate bored and threaded for a lathe's spindle nose from the manufacturer was probably possible. Basic thinking for threaded spindle noses is that fitting a chuck to a backplate was best done by machining the backplate on the spindle of the lathe it is to be run on.

    I remember in 1964, as a HS kid, walking into what used to be called a "Mill Supply"- a dealer in supplies and tools for machine shops, mills, and similar. There was a stack of rough castings for backplates, stacked up in descending size order. These had a cored hole in the middle of each casting, and that was the extent of any start on the machining. I have no idea what the price for those cast backplates was back in 1964, but I was floored at the current price for cast backplate blanks from Bison. The world has moved on to using lathes with camlock spindle noses, and even the long taper spindle nose system is fairly obsolete. Those of us who run lathes with threaded spindle noses are really back in the prehistoric times and we are on our own to come up with threaded backplates.

  4. #4
    Join Date
    Dec 2016
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    347
    Post Thanks / Like
    Likes (Given)
    6
    Likes (Received)
    143

    Default

    Quote Originally Posted by johnoder View Post
    A type spindle nose flanges have a drive "dowel" or "button" - that fits in the recess - for the purpose of not loading attaching bolts in shear



    Parsimonious Yankees?
    Thanks John. I suspected as much on both counts. That is, after i consulted Webster... ;-)


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
  •