Dividing Head as a Lathe Substitute
Close
Login to Your Account
Results 1 to 16 of 16
  1. #1
    Join Date
    Oct 2019
    Country
    UNITED STATES
    State/Province
    Indiana
    Posts
    10
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default Dividing Head as a Lathe Substitute

    Can a dividing head be used to accurately turn a piece down using a face mill and manually turning dividing head during the cut?

    It sounds silly, but my options are limited. My lathe is small and can't handle the piece in question. My new dividing head has a 3 jaw chuck large enough to mount the work piece. It seems like it would work, but I could be missing something. If I can knock off a 1/4 inch, I think I can mount it in the lathe to finish the job.

    MP

  2. #2
    Join Date
    Oct 2019
    Country
    NICARAGUA
    Posts
    106
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    41

    Default

    Give it a try, i think it would work.

  3. #3
    Join Date
    Oct 2013
    Location
    netherlands Asten
    Posts
    876
    Post Thanks / Like
    Likes (Given)
    552
    Likes (Received)
    373

    Default

    Quote Originally Posted by mpoore View Post
    Can a dividing head be used to accurately turn a piece down using a face mill and manually turning dividing head during the cut?

    It sounds silly, but my options are limited. My lathe is small and can't handle the piece in question. My new dividing head has a 3 jaw chuck large enough to mount the work piece. It seems like it would work, but I could be missing something. If I can knock off a 1/4 inch, I think I can mount it in the lathe to finish the job.

    MP
    sure it can, just take your time and be sure the workpiece is secured well and the dividing head also

  4. #4
    Join Date
    Jan 2012
    Location
    Midland, Texas
    Posts
    1,501
    Post Thanks / Like
    Likes (Given)
    498
    Likes (Received)
    761

    Default

    Sure!

    Here's a part I made on a rotary table that was just a little too large to do on my lathe.

    Notice the groove around the outside that was also cut on the mill.

    rotary-table-work.jpg

  5. Likes DrHook liked this post
  6. #5
    Join Date
    Jul 2004
    Location
    Houston, TX USA
    Posts
    30,265
    Post Thanks / Like

    Default

    Kinda slow - FORTY turns of crank to get one rev of workpiece

    Do pay attention to the fact that if the chuck is threaded on, the mill can unscrew it - depends on how you are cutting on it

  7. Likes eKretz, DrHook liked this post
  8. #6
    Join Date
    Dec 2015
    Country
    UNITED STATES
    State/Province
    Illinois
    Posts
    454
    Post Thanks / Like
    Likes (Given)
    147
    Likes (Received)
    257

    Default

    Be aware that a face mill only cuts on the perimeter so you can't park it over the centerline of the dividing head and expect it to cut much. Also using a round tool off center will give you a "hollow cut" as in you won't end up with a true cylinder.

  9. Likes Booze Daily liked this post
  10. #7
    Join Date
    Oct 2019
    Country
    UNITED STATES
    State/Province
    Indiana
    Posts
    10
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default

    Thanks for the feedback. Sometimes a person that has a little experience is more dangerous than a true beginner because he thinks he knows more than he really does. I was afraid that might have been the case here. My plan might still not have worked without your tips such as the right mill to use and the direction of cut to avoid unscrewing the face plate.

    Out of curiosity, has anyone ever tried to true a brake rotor on a RT? Seems like a very viable option.

    MP

  11. #8
    Join Date
    Apr 2004
    Location
    Modesto, CA USA
    Posts
    7,072
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    1194

    Default

    When the turned the 120 inch magnet coils for a cyclotron at Berkeley they had to flatten the face. So they mounted it to a surplus destroyer? gun mount and rotated it slowly under a bridgeport attached to the ceiling framework.

  12. Likes Dumpster_diving liked this post
  13. #9
    Join Date
    Jan 2012
    Location
    Southwest
    Posts
    1,103
    Post Thanks / Like
    Likes (Given)
    115
    Likes (Received)
    290

    Default

    Quote Originally Posted by kenton View Post
    Also using a round tool off center will give you a "hollow cut" as in you won't end up with a true cylinder.
    Can you explain why this would be the case? Why wouldn't a vertical, round tool that is cutting on its edge (e.g. an end mill) create a true cylinder in a part that is mounted horizontally on a rotary table that is off center?

  14. #10
    Join Date
    Jan 2007
    Location
    s w NH
    Posts
    333
    Post Thanks / Like
    Likes (Given)
    234
    Likes (Received)
    121

    Default

    consider using a variable speed drill with adapter to spin the head?

  15. #11
    Join Date
    Oct 2019
    Country
    UNITED STATES
    State/Province
    Indiana
    Posts
    10
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default

    Quote Originally Posted by metlcutr55 View Post
    consider using a variable speed drill with adapter to spin the head?
    Another great tip. Thanks.

  16. #12
    Join Date
    Nov 2003
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    5,107
    Post Thanks / Like
    Likes (Given)
    180
    Likes (Received)
    1606

    Default

    If the RT is mounted horizontally (It's axis is vertical) then there should be no problem.

    BUT if the RT is mounted vertically (it's axis is HORIZONTAL) then you do want the milling cutter to be directly above it's axis. This may be what Kenton was talking about.

    And if the RT is at an odd angle, then heaven help you. You are going to need some real deep geometry there.



    Quote Originally Posted by opscimc View Post
    Can you explain why this would be the case? Why wouldn't a vertical, round tool that is cutting on its edge (e.g. an end mill) create a true cylinder in a part that is mounted horizontally on a rotary table that is off center?

  17. #13
    Join Date
    Jan 2012
    Location
    Southwest
    Posts
    1,103
    Post Thanks / Like
    Likes (Given)
    115
    Likes (Received)
    290

    Default

    Quote Originally Posted by EPAIII View Post
    BUT if the RT is mounted vertically (it's axis is HORIZONTAL) then you do want the milling cutter to be directly above it's axis.
    In this circumstance the milling cutter would be doing its cutting only on one side of the cutter so would quite clearly not remove material evenly unless the table was moved back and forth parallel to the rotation axis of the rotary table. In which case it also would produce a cylinder.

  18. #14
    Join Date
    Dec 2015
    Country
    UNITED STATES
    State/Province
    Illinois
    Posts
    454
    Post Thanks / Like
    Likes (Given)
    147
    Likes (Received)
    257

    Default

    Quote Originally Posted by opscimc View Post
    In this circumstance the milling cutter would be doing its cutting only on one side of the cutter so would quite clearly not remove material evenly unless the table was moved back and forth parallel to the rotation axis of the rotary table. In which case it also would produce a cylinder.
    I saw dividing head and imagined using it with the axis horizontal, with the axis vertical no problem. As to running the tool back and forth, you could certainly do that but you will either end up spending a shit-ton of time milling 360 +/- passes and get something very cylinder like or spend a lot of time and accept that your part is a polygon and not a cylinder.

  19. #15
    Join Date
    Oct 2019
    Country
    NICARAGUA
    Posts
    106
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    41

    Default

    Out of curiosity, has anyone ever tried to true a brake rotor on a RT? Seems like a very viable option.
    No, but I have ground them on a flywheel grinder. Parallelism is the tough part. I run a file across the top part where the wheel fits against, just to make sure it is flat. Then put that side down on the table, secure and grind the inside surface. Flip and grind the outside. Never make any money on it with autozone doing them for $9, and new ones for $20. I only do odd ones that are high priced or unavailable. Or my own on a day when no one is open. The hot ticket is the spindle from a junk brake lathe. Mount it in your engine lathe and turn rotors, or anything with a concentric hole. Takes up less room than another machine, and cheap.

  20. #16
    Join Date
    Jul 2009
    Location
    NW Illlinois USA
    Posts
    427
    Post Thanks / Like
    Likes (Given)
    102
    Likes (Received)
    134

    Default

    Turning rotors: Stand up an extra spindle on your mill table to hold the rotor on its own bearings. Run a vee belt around the perimeter and power with a motor to spin the rotor. Then traverse a single point tool to true the surfaces.

    I've done this with unobtainable rotors for vintage vehicles. No way I'd bother on something that can be easily purchased.


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
  •