Results 1 to 5 of 5

Thread: Precise cutting of heavy brass tube

  1. #1
    Join Date
    Mar 2013
    Location
    Memphis TN
    Posts
    920

    Default Precise cutting of heavy brass tube

    I had a need to make bearings out of a brass tube and each piece had to be within a thousandth of spec. I had a brainstorm to use the SB as a measuring device and came up with this contraption.

    The rod is 1/2" diameter with a 1/4" inside diameter.

    The multitool is level and square to the machine and locked to a piece of 2x4 by landscaping tape and hot glue. Not exactly a permanent fixture but good enough for the job.

    To actually cut the rod, I used the keyboard function, "D" set at 0.001" and set the zero position within 0.02" of the multitool blade. Then I just arrow keyed the tube into the rod with the RPM's at 6,000. The wire runs up the tube a short distance and catches the rings as they separate.

    To repeat, I move Y to zero, zero Z and lowered the Z to the desired depth for the next cut.

    I made a couple of test cuts to calculate kerf and see how good the cut quality was and then subsequent cuts were good. I needed 12 at 0.250" and 4 at 0.500".

    After cutting, I cleaned them up with a disk sander and they were ready to use.

    IMG_20191210_171036.jpg
    ShopBot Details:
    2013 PRS Alpha 96x60x12
    4hp Spindle
    12" indexer
    Aspire
    Rhino
    Fusion 360
    Ferrari 360
    Prusa MK3S+

  2. #2
    Join Date
    Sep 2012
    Location
    Blaine Mn
    Posts
    334

    Default

    Did you cut with the multitool or run the spindle? I guess the spindle would be way too fast after seeing my words.

  3. #3
    Join Date
    Mar 2013
    Location
    Memphis TN
    Posts
    920

    Default

    The spindle was on, 6,000 RPM's and the multitool was also on. After the job, the blade looked untouched.
    ShopBot Details:
    2013 PRS Alpha 96x60x12
    4hp Spindle
    12" indexer
    Aspire
    Rhino
    Fusion 360
    Ferrari 360
    Prusa MK3S+

  4. #4
    Join Date
    Mar 2017
    Posts
    86

    Default Great thinking

    Quote Originally Posted by coryatjohn View Post
    I had a need to make bearings out of a brass tube and each piece had to be within a thousandth of spec. I had a brainstorm to use the SB as a measuring device and came up with this contraption.

    The rod is 1/2" diameter with a 1/4" inside diameter.

    The multitool is level and square to the machine and locked to a piece of 2x4 by landscaping tape and hot glue. Not exactly a permanent fixture but good enough for the job.

    To actually cut the rod, I used the keyboard function, "D" set at 0.001" and set the zero position within 0.02" of the multitool blade. Then I just arrow keyed the tube into the rod with the RPM's at 6,000. The wire runs up the tube a short distance and catches the rings as they separate.

    To repeat, I move Y to zero, zero Z and lowered the Z to the desired depth for the next cut.

    I made a couple of test cuts to calculate kerf and see how good the cut quality was and then subsequent cuts were good. I needed 12 at 0.250" and 4 at 0.500".

    After cutting, I cleaned them up with a disk sander and they were ready to use.

    IMG_20191210_171036.jpg
    Nice work John, I love your thinking, something I would dream up.

  5. #5
    Join Date
    Mar 2013
    Location
    Memphis TN
    Posts
    920

    Default

    Here's what I am making:

    00100trPORTRAIT_00100_BURST20191213132103685_COVER.jpg

    The tolerances in the hinge joint are just about right. Tight, but still loose enough to open under the weight of the clamp.
    ShopBot Details:
    2013 PRS Alpha 96x60x12
    4hp Spindle
    12" indexer
    Aspire
    Rhino
    Fusion 360
    Ferrari 360
    Prusa MK3S+

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •