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Brian builds a Corliss

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  • #31
    Just wondered if it would be possible to machine down the drum from a car brake to make that flywheel if you could find one approx the right size. Scrap yards are not as common as they used to be round here but they do still exist. Just a thought.

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    • #32
      I don't think there are too many cars around with 7 1/4" diameter brake drums. I'm not really into rescuing scrap steel from wrecking yards to build with. I have the money to buy a piece of pipe from the steel suppliers---I'll just whine about it a lot.🙄🙄
      Brian Rupnow
      Design engineer
      Barrie, Ontario, Canada

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      • #33
        Originally posted by brian Rupnow View Post
        I don't think there are too many cars around with 7 1/4" diameter brake drums. I'm not really into rescuing scrap steel from wrecking yards to build with. I have the money to buy a piece of pipe from the steel suppliers---I'll just whine about it a lot.🙄🙄
        It was just an idea. I like cheap so it would definately be an avenue I'd investigate. Lots of smaller cars here so probably not too hard to find something.

        Good luck with your build. I will enjoy watching your progress.

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        • #34
          Brian, sorry to get your hopes up, but the largest I could find was about 5 1/2" OD. I thought I had some larger stuff.

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          • #35
            Originally posted by RB211 View Post

            Seen some videos of that over on r/makemycoffin , not even close to the absolute worst I've seen over there.

            No thank you. Sounds sick and twisted. What are you trying to do? Give me bad dreams?
            My architecture has a foundation that is structurally compromised to begin with. Sheesh.

            -Doozer
            DZER

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            • #36
              Now it's time for me to take on opinion pole!!---The cylinder for this critter is 2 1/8" square x 2 1/2" long. I have a piece of aluminum here that is bought and paid for, but as I understand things, aluminum has a high coefficient of friction, which I'd like to avoid. Mild steel would work all right, because I will be running on compressed air, not steam. Only thing is, there are a ton of #4-40 and #5-40 tapped holes in this thing, and a very real chance of breaking a tap. I find that cast iron is easier to tap, but a phone call to my metal supplier this morning tells me it will cost $30 for a piece of 3" diameter cast iron x 3" long. What material do you recommend that I use?
              Brian Rupnow
              Design engineer
              Barrie, Ontario, Canada

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              • #37
                Originally posted by brian Rupnow View Post
                Now it's time for me to take on opinion pole!!---The cylinder for this critter is 2 1/8" square x 2 1/2" long. I have a piece of aluminum here that is bought and paid for, but as I understand things, aluminum has a high coefficient of friction, which I'd like to avoid. Mild steel would work all right, because I will be running on compressed air, not steam. Only thing is, there are a ton of #4-40 and #5-40 tapped holes in this thing, and a very real chance of breaking a tap. I find that cast iron is easier to tap, but a phone call to my metal supplier this morning tells me it will cost $30 for a piece of 3" diameter cast iron x 3" long. What material do you recommend that I use?
                Considering its a model and will only be run a very short total time the aluminum would be ok. That said, aluminum isn't that bad for friction as long as you have a good surface finish, many of the small engines (lawn mower type) use aluminum connector rods running directly on the crank. Being its a model and won't run on actual steam, you could make the piston out of some type of plastic. I just wouldn't run a aluminum piston in a aluminum bore.

                As for tapping the aluminum, the proper tapping fluid is important, many swear by WD40 even. On one of your prior engine projects the subject of hole size used to tap a given thread came up. You can go up a bit in hole size, for less thread engagement and still have plenty of strength BUT it will tap far easier. Good old fashioned Crisco also works well for tapping aluminum. Tapping fluids not intended for aluminum will actually bind up the tap sometimes.

                A sleeve in the aluminum block is also a option. You didn't say the actual bore size but maybe a pipe nipple could be used for this purpose cheaply.
                Last edited by Sparky_NY; 02-22-2022, 03:04 PM.

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                • #38
                  Sing Hallelujah baby---we got the first part made!!! It still needs a bit of fettling and a few holes, but I'm off to see a man about a flywheel.
                  Brian Rupnow
                  Design engineer
                  Barrie, Ontario, Canada

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                  • #39
                    I drove across town to my metal supplier and gave up $55 of the Rupnow Fortune for material. The flywheel as it sets is 7" o.d. x 3/8" wall thickness, which is close enough for me. The 6" x 1/2" aluminum is going to be the main baseplate, the 2" round cold rolled is going to become the cross-head guide, and the rest of the stuff is to make "feet" that holds the cylinder up.
                    Brian Rupnow
                    Design engineer
                    Barrie, Ontario, Canada

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                    • #40
                      I have changed the solid model to show the piece of 7" outside diameter pipe as a flywheel rim. I'm not going to show all of the notches around the flywheel rim, as they serve no purpose here and are not needed. I'm not 100% sure how to attach the spokes to the outer rim, but right now I'm thinking that if I can hold everything concentric I may make the spokes 0.100" too short and fill up the ends at the flywheel rim with tig weld. This will serve to hold the spokes in place and if I overfill the holes and then take a clean up pass on the outside diameter it should look okay.
                      Brian Rupnow
                      Design engineer
                      Barrie, Ontario, Canada

                      Comment


                      • #41
                        Originally posted by brian Rupnow View Post
                        I'm not going to show all of the notches around the flywheel rim, as they serve no purpose here and are not needed.
                        I presume the governor will not be ditched. Reply #22 hints at its function, but I don't really understand it
                        Allan Ostling

                        Phoenix, Arizona

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                        • #42
                          Originally posted by brian Rupnow View Post
                          I have changed the solid model to show the piece of 7" outside diameter pipe as a flywheel rim. I'm not going to show all of the notches around the flywheel rim, as they serve no purpose here and are not needed. I'm not 100% sure how to attach the spokes to the outer rim, but right now I'm thinking that if I can hold everything concentric I may make the spokes 0.100" too short and fill up the ends at the flywheel rim with tig weld. This will serve to hold the spokes in place and if I overfill the holes and then take a clean up pass on the outside diameter it should look okay.
                          Thats exactly how I made some spoked wheels several years ago. Lokset the spokes into the hub, leave the spoke ends about 1/8" recessed in the rim, then fill the recess with weld before machining. Worked well. Sorry, forgot, assemble on a jig to get concentricity before welding.
                          The governor will look nice if you like watchmaking, but its unlikely to be effective, not in the scale you are working in.

                          'It may not always be the best policy to do what is best technically, but those responsible for policy can never form a right judgement without knowledge of what is right technically' - 'Dutch' Kindelberger

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                          • #43
                            Today I made my machines pay for themselves. Started this morning at 9:30 and just finished up at 4:45. I'm very pleased with things so far.
                            Brian Rupnow
                            Design engineer
                            Barrie, Ontario, Canada

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                            • #44
                              Your projects certainly are "zippy".... I usually roll one around in my mind for a while and modify plans quite a bit before I cut metal. You are well into the building at the point in time I would be finalizing the plans. And I worked as a design engineer for decades.
                              CNC machines only go through the motions.

                              Ideas expressed may be mine, or from anyone else in the universe.
                              Not responsible for clerical errors. Or those made by lay people either.
                              Number formats and units may be chosen at random depending on what day it is.
                              I reserve the right to use a number system with any integer base without prior notice.
                              Generalizations are understood to be "often" true, but not true in every case.

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                              • #45
                                Brian:
                                I was going to suggest using a pipe coupling for 2 inch gas pipe for the cylinder sleeve, however it is only 2 inches long. You can get a 2 inch ID by 5 inch long pipe nipple for CDN$7.47 plus tax from AMRE supply in CehNehDeh )
                                Last edited by bob_s; 02-24-2022, 02:44 AM.

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