Announcement

Collapse
No announcement yet.

How to test an R8 taper?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • How to test an R8 taper?

    I got all ambitious and attempted the most critical machining I have ever tried, making an R8 arbor for my boring head, of course I could have bought one for the price of the electricity used! :lol:

    It is all finished now, the thread for the boring head fits well, the keyway seems right and the small end is a snug slide in but how do I test the taper?

    With a pin engaging the keyway I cannot blue and wring the taper to test for lock. I certainly do not have any measuring instruments that could test the taper angle (unless there is a method I dont know about).

    The best test I can do is whack it into place (with my hand) and it stays there.

    Any ideas please?

  • #2
    Blue up the spindle, press in the arbor, pop it back out, and check what transfers. Due to the keyway, that's the only way it can be installed, so that's the only
    position you care about the blue transferring.
    Location: Long Island, N.Y.

    Comment


    • #3
      Can you take out the key for a test fit,then reinstall?

      Comment


      • #4
        Hi, thanks for the advice.

        I have blued the spindle as suggested and made a slight change and it looks good now.

        Comment


        • #5
          Take the effin' collet index key out and throw it away. It will shear at 80 ft lb. That key has damaged more spindles and spindle tooling than all the other turrret mill sized wreck modalities combined.

          Anyway, remove the index set screw and blue the taper lightly. Rotate the tool a part rev while holding it in firm contact with the taper.

          Comment


          • #6
            I am sure that is good advice, I will take a peep up the hole and see how hard it would be to remove it.

            Comment


            • #7
              Mill something with 81 FT/LBs of force and it will remove it self.
              The shortest distance between two points is a circle of infinite diameter.

              Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

              Southwestern Ontario. Canada

              Comment


              • #8
                You could also turn a female gage if you have tooling with a known good taper to use for comparison. You then just blue your new arbor against that. OTOH, pulling the key is likely quite a bit easier.
                "I am, and ever will be, a white-socks, pocket-protector, nerdy engineer -- born under the second law of thermodynamics, steeped in the steam tables, in love with free-body diagrams, transformed by Laplace, and propelled by compressible flow."

                Comment


                • #9
                  Originally posted by Forrest Addy View Post
                  Take the effin' collet index key out and throw it away. It will shear at 80 ft lb. That key has damaged more spindles and spindle tooling than all the other turrret mill sized wreck modalities combined.

                  .
                  Pretty Much !
                  What a half-baked idea a whimp drive key was!

                  Comment


                  • #10
                    What is the result of spinning the arbor in the spindle after removing the drive key?

                    Comment


                    • #11
                      Use a BridgePort for a Bridgeport size / scope job.
                      Use tooling appropriate for a Bridgeport.
                      Use a force on the drawbar well matched to the cutting force.

                      The collet won't spin when doing the above.
                      As for face-mill arbors and solid endmill holders, well . . .
                      intellegence needs to play a roll here.

                      As In; knowing when to move up to a heavy-er machine
                      if yer do'n allotta that.

                      Comment


                      • #12
                        If you tighten the collet properly and don't over-power your machine, that key isn't going to shear. Or if it is, then after that the collet will always spin. Why? Because if it could spin with the key, then it can definately spin without it.
                        Amount of experience is in direct proportion to the value of broken equipment.

                        Comment


                        • #13
                          The key isn't a drive key. It's there to stop the collet spinning if the thread on either the drawbar or collet is tight when installing a collet.

                          If you check the threads from time to time to make sure you don't get any tight ones there is no further use for the key.
                          As Forrest has said it has wrecked more tooling.

                          Old hat makes a good point but assumes that everyone has a shop full of machines just designed for that one job. Real life often means you have to do the best with what you have.
                          .

                          Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



                          Comment


                          • #14
                            Nah, I just mean think before do.
                            I've spent thousands of hours on Bridgeports and copy's.

                            Improvise instead of overdrive. That's all I mean.
                            Cheers.

                            Comment


                            • #15
                              Originally posted by Old Hat View Post
                              I've spent thousands of hours on Bridgeports and copy's.


                              Cheers.
                              You have my heartfelt sympathies. I only spent 7 years nursing one before I sent the pile of junk over to India to make even more junk.
                              .

                              Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



                              Comment

                              Working...
                              X