Turning long and thin rod
Close
Login to Your Account
Page 1 of 2 12 LastLast
Results 1 to 20 of 21
  1. #1
    Join Date
    Nov 2019
    Country
    FINLAND
    Posts
    35
    Post Thanks / Like
    Likes (Given)
    18
    Likes (Received)
    2

    Default Turning long and thin rod

    Hi,

    I need to turn fairly long and thin bar. I’m thinking how should that be done. Finished product is mostly 8mm thick and 150mm long. However there is one shoulder with diameter of 11mm. If I were to make it from 11mm stock what might be the correct way of turning this? Some sort of steady rest which would be the opposite side of the cutting tool would be good but I only have huuuuge rest which doesn’t suit into this purpose.

    I was thinking of two options. Have that 11mm shoulder machined separately then press fit it afterwards. Then it could be made from 8mm stock. Or machine short distance at a time and then move that part out from the jaws and continue another distance. Neither of those sounds very good, but is there any other choice?

    Thank you in advance

  2. #2
    Join Date
    Jun 2019
    Country
    UNITED STATES
    State/Province
    Missouri
    Posts
    138
    Post Thanks / Like
    Likes (Given)
    65
    Likes (Received)
    91

    Default

    Collet, turn short distance, advance, repeat.

    Flip end for end and finish the head.

    If you need to, add a few m.m. to the skinny end and drill a center and use a live center.

    Easy peasy.

    PS, the steady rest will only get in the way.

  3. #3
    Join Date
    Dec 2008
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    10,219
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2654

    Default

    swiss machining, stick out, turn it, then stick out some more and turn some more
    .
    swiss lathes do this automatically some how, on a manual lathe you manually do it

  4. #4
    Join Date
    Jan 2007
    Location
    Norfolk, UK
    Posts
    18,937
    Post Thanks / Like
    Likes (Given)
    14441
    Likes (Received)
    14510

    Default

    use a roller box, - like this YouTube

    Exactly the sort of job a box tool's made for

  5. #5
    Join Date
    Aug 2008
    Location
    Sussex, England
    Posts
    3,393
    Post Thanks / Like
    Likes (Given)
    12
    Likes (Received)
    744

    Default

    I think Thunderjet is optimistic. On a skinny piece like that machine a bit, stick out a bit further and machine more pretty much guarantees that it will climb over the tool and go prestzel before you have finished. Even with teeny weeny cuts and a centre.

    As Limy says classic reason why roller boxes were invented.

    If you have a four way tool post or a QC system capable of mounting more than one tool without the carriers or shanks interfering a poor boys substitute for a roller box is an L plate style steady on a suitable shank held just behind the cutting tool. Not as strong as a proper roller box unless you go more serious on the engineering than a one time job is worth but it will get the job done. In two cuts rather than one. Or, if you don't have to get over that collaer mid cut, you could use a right size bush which probably will get the job done in one cut if well lubricated.

    Clive

  6. #6
    Join Date
    Sep 2011
    Location
    Norfolk England
    Posts
    2,285
    Post Thanks / Like
    Likes (Given)
    2631
    Likes (Received)
    1695

    Default

    Quote Originally Posted by Limy Sami View Post
    use a roller box, - like this YouTube

    Exactly the sort of job a box tool's made for
    Or a pointing toolholder

  7. Likes Limy Sami liked this post
  8. #7
    Join Date
    Feb 2012
    Location
    The warm desert of Phoenix Arizona
    Posts
    1,457
    Post Thanks / Like
    Likes (Given)
    330
    Likes (Received)
    508

    Default

    A seriously old school approach would be with a follow rest and light cuts.

  9. Likes tech610 liked this post
  10. #8
    Join Date
    Mar 2005
    Location
    Northwest Indiana
    Posts
    4,226
    Post Thanks / Like
    Likes (Given)
    852
    Likes (Received)
    852

    Default

    150mm long is only 6"... I'd think you could just stick it halfway in the chuck and turn half, then turn it around and turn the other half easy peasy. Not THAT bad of a L to D ratio if you do it half and half and use a good sharp tool with a very small nose radius. Could actually probably do it in one shot unsupported.

  11. #9
    Join Date
    Oct 2005
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    15,612
    Post Thanks / Like

    Default

    What is the lathe to be used ?

  12. #10
    Join Date
    Sep 2004
    Location
    Sonora , Calif
    Posts
    577
    Post Thanks / Like
    Likes (Given)
    119
    Likes (Received)
    121

    Default

    Look up Frank Ford follow rest.

    I would also use a box tool.

  13. #11
    Join Date
    Sep 2018
    Country
    UNITED STATES
    State/Province
    New Jersey
    Posts
    16
    Post Thanks / Like
    Likes (Given)
    26
    Likes (Received)
    0

    Default

    I would use a follower rest.

  14. #12
    Join Date
    Jan 2007
    Location
    Norfolk, UK
    Posts
    18,937
    Post Thanks / Like
    Likes (Given)
    14441
    Likes (Received)
    14510

    Default

    Quote Originally Posted by digger doug View Post
    What is the lathe to be used ?
    5A W&S with a 75 HP motor.

  15. #13
    Join Date
    Apr 2011
    Location
    Nebraska
    Posts
    1,251
    Post Thanks / Like
    Likes (Given)
    1785
    Likes (Received)
    367

    Default

    If you can get away with a two piece I'd just drill an 8mm hole in the 11mm stock and insert the 8mm bar in to it. You can do a heat/cool fit, Loctite retaining fluid, pin it, etc. No messing around with trying to get a long thin bar on the lathe.

    JMHO

    -Ron

  16. Likes Limy Sami, Peter from Holland liked this post
  17. #14
    Join Date
    Mar 2014
    Location
    Nebraska
    Posts
    370
    Post Thanks / Like
    Likes (Given)
    42
    Likes (Received)
    232

    Default

    I agree. If a press fit head is permitted why even bother trying to turn it? Order TGP 8mm shaft, machine the head, press it on, call Bob your Uncle to finish it.

  18. Likes Limy Sami liked this post
  19. #15
    Join Date
    Jun 2012
    Location
    Michigan
    Posts
    4,736
    Post Thanks / Like
    Likes (Given)
    4345
    Likes (Received)
    2878

    Default

    Quote Originally Posted by Limy Sami View Post
    use a roller box, - like this YouTube

    Exactly the sort of job a box tool's made for
    That's pretty cool, but I'm boycotting them. Twice they mention that it's marketed toward engineers.
    What the fuck do engineers know about machining? At least 99% of them anyways.

  20. #16
    Join Date
    Jan 2007
    Location
    Norfolk, UK
    Posts
    18,937
    Post Thanks / Like
    Likes (Given)
    14441
    Likes (Received)
    14510

    Default

    Quote Originally Posted by Mtndew View Post
    That's pretty cool, but I'm boycotting them. Twice they mention that it's marketed toward engineers.
    What the fuck do engineers know about machining? At least 99% of them anyways.
    Ah/ that is more to do with translation, in the USA and on the tools guy on the shop floor is a machinist, the guy at the drawing board the engineer.
    In the UK the guy getting his hand dirty is often called an engineer, the guy on the drawing board a draftsman or designer.


    So when tangi Flow say it's marketed towaeds engineers, they mean the guys actually using the tool

    Confusing isn't it.

    Oh and boycott who you like

  21. Likes MetalCarnage liked this post
  22. #17
    Join Date
    Oct 2005
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    15,612
    Post Thanks / Like

    Default

    Quote Originally Posted by Limy Sami View Post
    Ah/ that is more to do with translation, in the USA and on the tools guy on the shop floor is a machinist, the guy at the drawing board the engineer.
    In the UK the guy getting his hand dirty is often called an engineer, the guy on the drawing board a draftsman or designer.


    So when tangi Flow say it's marketed towaeds engineers, they mean the guys actually using the tool

    Confusing isn't it.

    Oh and boycott who you like
    Or the one blowing the whistle on the loco....

  23. Likes Limy Sami liked this post
  24. #18
    Join Date
    Jan 2007
    Location
    Norfolk, UK
    Posts
    18,937
    Post Thanks / Like
    Likes (Given)
    14441
    Likes (Received)
    14510

    Default

    Quote Originally Posted by digger doug View Post
    Or the one blowing the whistle on the loco....
    YouTube

  25. Likes digger doug, 4GSR liked this post
  26. #19
    Join Date
    Oct 2005
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    15,612
    Post Thanks / Like

    Default

    Quote Originally Posted by Mtndew View Post
    That's pretty cool, but I'm boycotting them. Twice they mention that it's marketed toward engineers.
    What the fuck do engineers know about machining? At least 99% of them anyways.
    Rutt - Roh

    Limy better explain the term "bespoke" as well.....

  27. #20
    Join Date
    Jan 2007
    Location
    Norfolk, UK
    Posts
    18,937
    Post Thanks / Like
    Likes (Given)
    14441
    Likes (Received)
    14510

    Default

    bespoke meaning - Google Search

    bespoke
    /bɪˈspəʊk/

    adjectiveBritish

    adjective: bespoke
    made for a particular customer or user.
    "a bespoke suit"

    making or selling bespoke goods, especially clothing.
    "the bespoke tailors of Savile Row"

  28. Likes digger doug 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
  •