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Producing an Internal Bore Around Corners Without Tooling

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  • Producing an Internal Bore Around Corners Without Tooling

    To All
    After seeing my Monitor Steam Engine, many guys want to know how I made the pipe from solid (more or less), so I have decided to show the process here. JCHannum will be excited because he now no longer has to wait .

    Lets start off by saying that I tried to cast the pipe 17 times, and each time was a failure, which I will not review here, other than to say it was mostly a porosity problem. Determined to make it from scratch, I came up with what I believe is an original way of making elbows, without using any Special Tooling like rotary table, indexers, or CNC , and no casting !.
    In this photo you see the #17 Pipe which failed when it was polished.
    It is sitting on the print that shows dimensions and form. Please note,that to cast it, I had to forego the throttle box unit which was an integral part of the original engines' Steam Inlet Pipe. Something I was not happy with,
    to say the least

    So I cast in Bronze, a full size solid block to work with.

    Now the bore I wanted was 9/16 for scale, But I decided to use 1/2 for my passageway. here a 1/2 long ball mill is milling the horizontal passage, and my depth would be to the top of the pipe internally. note that I only mill upto the flange portion of the block

    Then I milled as deep as I could without breaking out of the top(we're upside down !) of the "desired" pipe, AND, I am careful to not get too close to the flange area.
    I have to leave room for a plug (next photo) with full depth. What I am trying to do is get around the corner a little bit. These photos were taken after the pipe was bored, so they are reproduction shots. What you do not see is my extensive use of cad prints---Full SIZE--It helps
    I take the drawing you saw in photo #1 and make several full size ones, and cut them out square to match the castings edges (!) and glue them to the casting sides --accurately ! I take a spare print and position it on the far vice jaw and determine the angle I want from it, and the depth and length of my cut by eyeballing the cutter and setting stops. then I place the real block in the exact same spot and do my undercutting. If you look at the cut, you can see about 1/4" left in the slot that is the bottom of the pipe

    To be continued.

  • #2
    next, I made a Key of the same material ,to be silversoldered, on the bottom of the pipe so it is out of sight. Note the cross drilled hole for the throttle box. The key is made as close to size as possible, for good looks, and has a flange left to act as a stop. The key is a nice little rotary table job if you want, or fitted by hand

    After Soldering, it is checked for voids, by milling

    Next the throttle plate is soldered. Note that a hole exists to vent gases during the SS workand that the hole matches a "grid" slot .

    Now to the "Meat" of the project. Using a ball mill (!) , remove some of the pipe bore at the flange to about 1/2 depth --rough
    NOW----Put in a Ball Burr (1/2" shown) in the spindle and tie some bailing wire to the quill tightly. bend the wire until it is EXACTLY on cerline with the ball portion of the Burr.. Now, equally important is to mark the centerline of the pipe . I used the C/L on the Cad drawing that was glued to my part, but I have marked it out here for the photos


    • #3
      We are looking straight in on the wire C/L in this shot

      Now plunge in and keep the wire on the C/L by moving the quill down and the X axis only ( Y was clamped from day 1 ). The BALL BURR makes this as easy as can be . There is NO grabbing, or jumping. The burr is smooth as silk and the C/L is very easy to follow NO special location needs to be used !, just expose C/L Marks above vice jaws.

      The neat part, is that the material can be positioned to any angle WITHOUT gauges, trig, or fixtures. If you see the C/L, you can cut it.
      Please note how deep I am into the pipe. the wire is the BALL !

      the finished hole with very fine chips.


      • #4
        How does this look? Reminds me of my dentist !
        Note that angles and setups are irrelevent !

        The last operation is lots of filling. Here is a piece of steel that was drilled through, and then Counterbored to the exact flange depth and diameter.
        A small rope was knotted and fed through the pipe , then through the C'B and tied to the bench leg at the floor. The knot pulls the pipe tight into the C/B when stepped on. this allows easy handling of the pipe hands free. To rotate the pipe I lighten up on the foot pressure, turn the pipe and file again. Please note the Grid Valve face milled in the throttle valve

        thanks for your attention


        • #5
          Wow, just Wow, i dont know what to say


          • #6
            Rich, you can have my attention anytime you want it!



            • #7
              Wow, thanks for the pics and explanation.

              I wish more people would post the creative setups and techniques like you just did! I've still got a LOT to learn, even including basics, but I've generally got to a point where I can manage the straight forward basic stuff without much mental stress. But there are still so MANY things that I just would never conceive. Things like you covered in this post. Thank you...
              Master Floor Sweeper


              • #8
                Wow, that's great!

                Rich, how did you machine the outside of the tube? It has a bellow look to it.


                • #9
                  Thanks for all the photos!
                  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                  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.


                  • #10
                    Thanks Rich for the great description and the excelllent photos. I had to re-read your post a couple of times before I completely understood the entire posting.
                    What you have done is to show that the seemingly impossible is sometimes doable if you don't give up and you continue to think about each obstacle and what you need to do in order to get around or through the various problems. Most people would probably have thrown in the towel before getting a finished product....but you were obviously a "Man on a Mission", and simply refused to allow the problem to defeat you. I salute both your work and the attitude you showed in refusing to go down in flames. Postings such as yours give hope to the rest of us and prove that using your brain and ingenuity can be the best tool we will ever own. Thanks again.
                    There is no shortage of experts, the trick is knowing which one to listen to!


                    • #11
             post #3 of this thread the first picture shows milling marks on the outer circular contour. These appear to have been done on a CNC, is that correct?

                      If so, why wasn't the inside done this way also?


                      • #12
                        I cant find words to describe my amazement!!

                        And to think that, -- even I,-- have tools that are very similar to those that this work was done on...... Sigh!,-- if I could JUST get it OUT of em!!

                        Rich, this pictoral display and description is fascinating, would you possibly have documented other areas of the construction? If so, PLEASE share another --or 2, or 3-- with us.

                        Beautiful clear pix and clear, descriptive dialogue of the process ... thanks for sharing.
                        If everything seems to be going well, you have obviously overlooked something........


                        • #13
                          While every one is astounded and bragging on Rich's work, I for one am not fooled, it should be obvious that he has magic tools, not available to the rest of us.

                          Your engine is a work of art, much the same can be said on your dedication to completing it.

                          Thanks for taking the time to share.


                          • #14
                            Its testimonial on what you went through to build it and the rest of the engine, Not many would have the patients or the skills, (maybe that peirre scerrie guy who built the v-12 ferrari )

                            I too was wondering how you did that tube, I did not consider a cutout and was trapped into thinking one solid unit - no exceptions --- My only thought on how I would try it if I was held down to those rules, Extrude honing, start off with really small holes that you connected ( a bit of a task but I think it could be done) then pump a dough type putty through that contains abrasive compounds, the elbow edges would get thin in a hurry around the bends but you could constantly disassemble, measure, and then coat the thinner area's with a epoxy shield, re-pump, disassemble --- recalibrate all the places where you need to apply the shielding --- re-pump, It would take some predictability on the last stage because some area's would wear at such an uneven rate, but when you got it close enough you could throw it into a solution to dissolve all shielding material and then one final extrude hone to blend everything together, Just a thought -- its how some guys hog out their formula V intake manifolds, Inside diameters are free for modification, all they care about is that the OD's are box stock...

                            Beautiful work Rich, (and very controlled I might add)


                            • #15
                              These kind of jobs are always fascinating to look at. In fact, I find undercutting jobs of any kind to be very interesting. My biggest concern about it all is I just wont think to do these things myself in a million years!

                              Thanks for the many good ideas I'm taking away:

                              - I love the burr with center line tracking wire. First I'd seen anything like that.

                              - I am reminded AGAIN that silver solder is a wonderful tool in the arsenal and can be almost invisible in practice.

                              - Your key is very nicely made. I'll need to work on my rotab skills to get there, but they're steadily improving. In all likelihood I'll be in a position to CNC such a key before I can do it manually.

                              - I am reminded AGAIN to square things up before beginning more complex operations. Somehow this is something nobody seems to say, but the best machinists always do it. I'm early in the learning curve, but deciding to square stock before attempting any operations really improved my milling accuracy and it was also just more fun to work on a nice squared workpiece. Same thing on the lathe.

                              - I see you're writing on the vise with your Sharpie. Writing key numbers down is a practice that helped me a lot in my early days and I keep right on doing it. Got a stack of steno pads and a box of Sharpie's. I'll often key things into my calculator too.

                              Thanks again for sharing. I wish more people would give the blow by blow, even on simple projects. There is so much to be learned and pictures really are worth a thousand words.



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