Keyway broach 5" - 6" long help - Page 2
Close
Login to Your Account
Page 2 of 3 FirstFirst 123 LastLast
Results 21 to 40 of 42
  1. #21
    Join Date
    Jul 2007
    Location
    Missoula Mt
    Posts
    1,450
    Post Thanks / Like
    Likes (Given)
    62
    Likes (Received)
    733

    Default

    Wrong machine tool, use a slotter...Phil

  2. #22
    Join Date
    Mar 2005
    Location
    Kansas
    Posts
    8,797
    Post Thanks / Like
    Likes (Given)
    632
    Likes (Received)
    4522

    Default

    Quote Originally Posted by Phil in Montana View Post
    Wrong machine tool, use a slotter...Phil
    What he said.

    Chip load is ground into the broach. The only way to change is to angle grind the back of the broach.

  3. #23
    Join Date
    Apr 2004
    Location
    Modesto, CA USA
    Posts
    8,947
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    1774

    Default

    How about broach it say 1/2 way deep then remove the tool and bush out the gullets. Similar to peck drilling.
    Bill D

  4. #24
    Join Date
    May 2012
    Location
    Pittsford, NY
    Posts
    1,207
    Post Thanks / Like
    Likes (Given)
    844
    Likes (Received)
    855

    Default

    If the material is too ductile, you get a little roll of chip in each gullet. Trying to back out requires breaking off every chip. The chips try to wedge between the cut and the back relief on every tooth.

  5. #25
    Join Date
    Mar 2003
    Location
    Vermont
    Posts
    533
    Post Thanks / Like
    Likes (Given)
    131
    Likes (Received)
    149

    Default

    Quote Originally Posted by wheels17 View Post
    If the material is too ductile, you get a little roll of chip in each gullet. Trying to back out requires breaking off every chip. The chips try to wedge between the cut and the back relief on every tooth.
    I agree, never reverse push a broach out of the cut. Just remove the bushing and lift the broach out of mesh.
    As mentioned, all of this is clearly detailed on Dumont's site. Cringe reading bad advise.

  6. #26
    Join Date
    Dec 2008
    Location
    minnesota
    Posts
    222
    Post Thanks / Like
    Likes (Given)
    59
    Likes (Received)
    217

    Default

    Here is a random thought:

    Perhaps you could make a broach bushing with the back of its slot
    angled about half as much as the broach is tapered.

    Then use shims half the thickness of standard and take more and lighter cuts?
    (passes) ?????

  7. Likes Overland liked this post
  8. #27
    Join Date
    Jun 2019
    Country
    UNITED STATES
    State/Province
    South Dakota
    Posts
    155
    Post Thanks / Like
    Likes (Given)
    47
    Likes (Received)
    55

    Default

    Dumont D series is designed for up to 6" cuts. I've used them for such with no issues in both steels and irons. May not be feasible for short run jobs, cost wise, but if you'll be using them again later anyway they make life easier.

  9. #28
    Join Date
    Nov 2017
    Country
    UNITED STATES
    State/Province
    South Carolina
    Posts
    203
    Post Thanks / Like
    Likes (Given)
    45
    Likes (Received)
    57

    Default

    Refer to the experts - Dumont.
    The issue is going to be chips loading the gullets, and the force to push so many teeth in contact at the same time.
    The depth of cut is designed into the broach, with the progressive height difference of each tooth.
    Three ways to reduce this that I can think of:
    - grind a taper on the back of the broach to reduce the height difference of each tooth,
    - grind down each tooth a little progressively from the thickest end.
    - make one shim a tapered shim to have the same effect, then you add or remove tapered shim on each pass so you're effectively almost halving the depth or length of cut. Easy to make the shim on a surface grinder.

    It all depends on what Dumont says.
    Bob

  10. #29
    Join Date
    Nov 2017
    Country
    UNITED STATES
    State/Province
    California
    Posts
    383
    Post Thanks / Like
    Likes (Given)
    253
    Likes (Received)
    251

    Default

    I've broken a tooth out of a broach trying to broach too much length. If permissible, drill a hole slightly larger than keyway width at the middle of the part, broach inline with the hole. This will allow the chips to escape. If necessary, plug the hole afterwards.

  11. #30
    Join Date
    Jul 2006
    Location
    Hillsboro, New Hampshire
    Posts
    14,351
    Post Thanks / Like
    Likes (Given)
    3137
    Likes (Received)
    9541

    Default

    I don't know if this will help, or if you want to risk it, but I've made fixturing to turn a CNC machine (VMC, but could be done on a lathe too) into a broaching machine.

    Ideally mounted in a way that puts no load into the spindle bearings, but with sufficiently light cuts even that can work. Stable, stiff cutter holding is key (sorry), as is patience with just taking lots of light passes.

    No need to have a full-width cutter either, for wider keys use a narrow cutter, cut the two outer (to final width) sections), then chase out the middle. It's stable in that order, I wouldn't do the middle and then the two sides.

    [This also can work for profiling gears and similar non-rotary cutting]

  12. Likes 52 Ford liked this post
  13. #31
    Join Date
    May 2021
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    346
    Post Thanks / Like
    Likes (Given)
    379
    Likes (Received)
    89

    Default

    Quote Originally Posted by Milland View Post
    I don't know if this will help, or if you want to risk it, but I've made fixturing to turn a CNC machine (VMC, but could be done on a lathe too) into a broaching machine.

    Ideally mounted in a way that puts no load into the spindle bearings, but with sufficiently light cuts even that can work. Stable, stiff cutter holding is key (sorry), as is patience with just taking lots of light passes.

    No need to have a full-width cutter either, for wider keys use a narrow cutter, cut the two outer (to final width) sections), then chase out the middle. It's stable in that order, I wouldn't do the middle and then the two sides.

    [This also can work for profiling gears and similar non-rotary cutting]
    Stefen Gotteswinter on YouTube has at least one video doing something that with a manual mill. I wanna say he cut internal splines in a socket for some odd fasteners on an aircraft engine - something like that. Must work well, he sold his shaper. Given, space is at a premium, but still.

    Sent by telegraph using - .- .--. .- - .- .-.. -.-

  14. #32
    Join Date
    May 2021
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    346
    Post Thanks / Like
    Likes (Given)
    379
    Likes (Received)
    89

    Default

    Here ya go. Cutting an internal keyway on a manual mill.

    https://youtu.be/s7MBl_cWXrc


    Sent by telegraph using - .- .--. .- - .- .-.. -.-

  15. #33
    Join Date
    Jul 2006
    Location
    Hillsboro, New Hampshire
    Posts
    14,351
    Post Thanks / Like
    Likes (Given)
    3137
    Likes (Received)
    9541

    Default

    Quote Originally Posted by 52 Ford View Post
    Here ya go. Cutting an internal keyway on a manual mill.

    https://youtu.be/s7MBl_cWXrc


    Sent by telegraph using - .- .--. .- - .- .-.. -.-

    I'm lazy, I prefer my machines do the work...

    Oh, and:

    .. .----. -- / .-.. --- --- -.- .. -. --. / ..-. --- .-. / .- / ... -- --- -.- . / ... .. --. -. .- .-.. / - .-. .- -. ... .-.. .- - --- .-. / -....- / -.. --- / -.-- --- ..- / -.- -. --- .-- / --- ..-. / --- -. . ..--..

  16. #34
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    9,820
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    4711

    Default

    Quote Originally Posted by Milland View Post
    Oh, and:

    .. .----. -- / .-.. --- --- -.- .. -. --. / ..-. --- .-. / .- / ... -- --- -.- . / ... .. --. -. .- .-.. / - .-. .- -. ... .-.. .- - --- .-. / -....- / -.. --- / -.-- --- ..- / -.- -. --- .-- / --- ..-. / --- -. . ..--..
    Why go halfway ? More parts, more better

    -*** / *- / -*-* / ****

    https://youtu.be/GCfqCiRvZA4

  17. #35
    Join Date
    Jul 2006
    Location
    Hillsboro, New Hampshire
    Posts
    14,351
    Post Thanks / Like
    Likes (Given)
    3137
    Likes (Received)
    9541

    Default

    Quote Originally Posted by EmanuelGoldstein View Post
    -*** / *- / -*-* / ****

    https://youtu.be/GCfqCiRvZA4
    My second-favorite organ...

  18. #36
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    9,820
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    4711

    Default

    Quote Originally Posted by Milland View Post
    My second-favorite organ...
    Try this then, it's a little different

    https://youtu.be/UMwctRJcHcc

    If you like cnc and Ingersoll planer mills, you have to appreciate pipe organs

  19. #37
    Join Date
    Jul 2006
    Location
    Hillsboro, New Hampshire
    Posts
    14,351
    Post Thanks / Like
    Likes (Given)
    3137
    Likes (Received)
    9541

    Default

    Quote Originally Posted by EmanuelGoldstein View Post

    If you like cnc and Ingersoll planer mills, you have to appreciate pipe organs
    Wrong-O, you commie rat-bastard organ-dealer. Are you stealing those organs? What churches have woken up in a bathtub filled with ice, with sloppy stitches covering over the wound where their organ used to be?

    Hummm??

    Besides, I'm more of a Jacquard loom kinda guy. Now THERE'S your connection to our beloved CNC machines.

    [True story: when I was a young Milland and going to summer camp, I actually made a shuttle loom in the crafts barn, and used that loom to weave a very nice belt. I also made an investment cast sterling silver ring while I was there.

    I should have gone to art school and become wealthy, instead I became a machinist. From young artisan to grizzled shop ghoul - there's a narrative arc with a bad ending...]

  20. #38
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    9,820
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    4711

    Default

    Quote Originally Posted by Milland View Post
    I'm more of a Jacquard loom kinda guy.
    Punch cards, pffft. Player pianos and organs use paper tape. Modern

  21. #39
    Join Date
    Jun 2009
    Location
    Michigan, USA
    Posts
    5,738
    Post Thanks / Like
    Likes (Given)
    3567
    Likes (Received)
    2612

    Default

    Quote Originally Posted by Bill D View Post
    How about broach it say 1/2 way deep then remove the tool and bush out the gullets. Similar to peck drilling.
    Bill D
    Have you ever tried to back out a broach that is halfway through the cut. I have a tip for you. Make sure that you have a spare broach handy first.

  22. #40
    Join Date
    Jun 2009
    Location
    Michigan, USA
    Posts
    5,738
    Post Thanks / Like
    Likes (Given)
    3567
    Likes (Received)
    2612

    Default

    Quote Originally Posted by 52 Ford View Post
    Here ya go. Cutting an internal keyway on a manual mill.

    https://youtu.be/s7MBl_cWXrc


    Sent by telegraph using - .- .--. .- - .- .-.. -.-
    I've cut keyways this way but good luck cutting one that is 6" deep and over 1/4" wide.


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
  •