Announcement

Collapse
No announcement yet.

boring problems...

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

  • boring problems...

    I need to clean up the 1.25" diameter, 5" deep bore for the piston valve on the 2.5" x 2.5" steam engine I'm rebuilding... and my 2" boring head doesn't look like it will be happy w/ a 1/2" diameter boring bar that long.

    I thought about line boring it on the lathe, but can't figure out how to mount the cylinder on the cross slide w/ a lot of complications, and setting the protrusion of the toolbit seems awkward as well. I guess I could bolt the cylinder on the lathe faceplate, but that's a lot of cast iron winging around. ...

    The simplest idea seems to be to get a bigger boring head so I could mount 3/4" boring bars.

    Has anyone got a better idea? What do people thing of the cdco tools 3" boring head?

    - Bart
    Bart Smaalders
    http://smaalders.net/barts

  • #2
    Piston valve bore

    Too bad you live so far South, I could hone it for you on my Sunnen hone. Find someone close to you who has one, should clean up in an hour or so. Peter
    The difficult done right away. the impossible takes a little time.

    Comment


    • #3
      Mybe it is just me but I can never bore holes sucessfully with a boring head on a milling machine...All I get is constant chatter..

      I would be setting it up on the lathe or getting it honed..
      Precision takes time.

      Comment


      • #4
        When building a model John Deere engine, I was faced with the same problem. I made a sub table to replace the compound. I used a piece of 1" thick aluminum.


        I cribbed the casting in place and used hold downs to hold it in place. The rear of the engine would not premit line boring, so I made a very stout boring bar to hold the cutter.


        I had acquired this gage in my roamings, and it works very well for setting the cutter protrusion. For one time use, a similar gage could be made by clamping a depth mic to a V-block.
        Jim H.

        Comment


        • #5
          That's pretty slick JC.
          - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
          Thank you to our families of soldiers, many of whom have given so much more then the rest of us for the Freedom we enjoy.

          It is true, there is nothing free about freedom, don't be so quick to give it away.

          Comment


          • #6
            You a clever devil, JC -- Slick set-up....
            If everything seems to be going well, you have obviously overlooked something........

            Comment


            • #7
              Same only different!

              I use DeVlieg adjustable boring bars and have since this pic made a 12" X 18" X 1.250" thich alum bed plate. Luckily, it has a large T-slotted cross slide.



              Glenn

              Comment


              • #8
                For line boring same as JCH's setup but with a between centres (centers) boring bar made from 1" dia. material.

                Regards Ian.

                The old ones are the best ones
                You might not like what I say,but that doesn't mean I'm wrong.

                Comment


                • #9
                  Originally posted by Glenn Wegman
                  Same only different!

                  I use DeVlieg adjustable boring bars and have since this pic made a 12" X 18" X 1.250" thich alum bed plate. Luckily, it has a large T-slotted cross slide.



                  Glenn
                  Glenn,

                  That's a VERY interesting operation.

                  I'm even more intrigued by the drill chuck with S&D drill plugged into the top right corner. Could you tell me more about when and how I'd use that particular trick?
                  .
                  "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

                  Comment


                  • #10
                    Sometimes you have to stop in the middle of a job and make tooling or fixtures to complete it. It pays to take your time and make a fixture that will be useful in the future. That was the case with the sub base I made. I did take the time to drill & tap sufficient 3/8-16 holes for future use. It is expendable if need be, and other holes can be added as necessary. It has taken it's place with the rest of the lathe tooling and comes in handy from time to time.

                    Glenn's drill chuck appears to be in a bed turret, but that still is a very impressive set up.
                    Jim H.

                    Comment


                    • #11
                      Bart, I have made several boring bars 1" diameter with a 1/2" shank to fit the boring head. I use brazed carbide cutter in the end of the bar. Some of them have the cutter at 90 deg and some have the cutter at 45 deg.

                      You can also make a bar with a pilot at the end and mount the work high enough to use the bar in a collet and do it like a line bore setup. You could hang the work off the side of the table. There are a lot of ways to do it on the mill.

                      I have bored holes with home made bars in boring heads and used the full travel of the quill and got a good surface finish. Test bore with some scrap if you can.
                      It's only ink and paper

                      Comment


                      • #12
                        Yup, six station bed turret

                        Comment


                        • #13
                          Originally posted by Glenn Wegman
                          Same only different!

                          I use DeVlieg adjustable boring bars and have since this pic made a 12" X 18" X 1.250" thich alum bed plate. Luckily, it has a large T-slotted cross slide.



                          Glenn
                          Gee, I wonder what size and model radial you are working on there. Looks like you are repairing the magneto mounting area
                          Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

                          Comment


                          • #14
                            Thanks folks; now I have some interesting ideas to mull over... I particularly like the idea of building a proper line-boring plate for the lathe, and that gage seems like the right approach. Seeing those pictures gives me some confidence that I can make this work.

                            I'll try making some tapered collars for the boring bar to center the cylinder casting during setup...

                            - Bart
                            Bart Smaalders
                            http://smaalders.net/barts

                            Comment


                            • #15
                              You might want to snug your cross slide gibs up a little so the slide doesn't want to move in and out with the bar rotation if you plan on taking much of a cut, or have an interrupted cut when you start out. I zero'd my .0002" resolution DRO in X and it never even flickered during the cut. I did some fairly heavy cuts in steel one other time and the slide wanted to move back and forth a little, but I just zero'd it back up for the finish passes and it was fine.

                              Glenn

                              Comment

                              Working...
                              X