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  • Need Help With Pattern Making

    I am trying to make a set of pattern to make castings for a small steam engine, that was in Popular Science in the summer of 1946. What I want to know is there a material that can be use to make cores rather than making core boxes, to make sand cores. My reasoning being it is easer to make a core rather than a core box. If there is such a material where can I buy it.


    Jim Connell

    PS
    I failed to say that it is not a cylinder shaped core I need but a block wider than thick with a smaller block attached plus core prints , radius corners and draft.
    Last edited by jcon; 10-13-2011, 09:08 AM.

  • #2
    Jim, I'm neither a pattern maker nor a metal caster, I hope to get there one day though, and from what I read when I peruse this site http://www.alloyavenue.com/vb/forumd...casting-forums everyone still seems to make core boxes to cast their cores rather than making their cores directly.

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    • #3
      You can use sodium silicate mixed with sand. Look up no-bake cores.

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      • #4
        Choices

        There are several ways to avoid making a core box.
        1) Find someone with a Z-Corp printer and the correct materials to print your cores. You have to furnish or pay for a .stl mesh file of your cores. This could be hard to find such a source.

        2) Find a foundry supply house that sells premade cores in the form of cylinders. You might have to buy a bunch of them.

        3) Try carving the "no-bake material. This process will require you to have a method to infilltrate the mixture with CO2.

        So it gets down to the cheapest method is a core box. This is more important when you either flub a casting or want to build another engine.

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        • #5
          The only part that is usually cored is the cylinder. There is no reaason not to cast it solid and bore it out. It is not very much metal, so cost is not an issue.
          Duffy, Gatineau, Quebec

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          • #6
            Isn't there a "lost foam" process in which you make the core of Styrofoam and the hot metal just vaporizes it when you pour? (I may be totally misguided, so seek independent confirmation.)
            ----------
            Try to make a living, not a killing. -- Utah Phillips
            Don't believe everything you know. -- Bumper sticker
            Everybody is ignorant, only on different subjects. -- Will Rogers
            There are lots of people who mistake their imagination for their memory. - Josh Billings
            Law of Logical Argument - Anything is possible if you don't know what you are talking about.
            Don't own anything you have to feed or paint. - Hood River Blackie

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            • #7
              No, wherever there is foam it will be replaced with metal and you will have a shop full of foul smelling smoke. Peter.
              The difficult done right away. the impossible takes a little time.

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              • #8
                To make a simple core for a cylinder,can you just clamp 2 pieces of wood together,and drill right through the center line,perhaps with a Forstner bit? Then,just keep one of the 2 halves to mold your cores. You also have to make core prints on the ends of your cylinder pattern to lay the core into.

                Good suggestion to just make the cylinder solid,and bore it out. You might get a more solid casting that way,too(less holes).

                I had to make 6" cores about 22"long when I made the 30 patterns for the 18th.C. reproduction fire engine for Williamsburg. Those I planed with a shop made core plane.

                If there are other cores that aren't round,that's another matter,but they aren't terribly difficult to make. Especially if small.

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                • #9
                  Since it is just for the cylinder just get a pre-made core the right size.

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                  • #10
                    I've made cores from mixing the sand with linseed oil and baking @ 350 degrees F. For the core mold I simply split cast iron pipe of the appropriate diameter and used hose clamps to hold them together.

                    One more thing. Go to Lindsay's Technical Books and buy their reprint of the Navy's Foundryman book. Hands down the best practical sand casting book you can get.
                    Last edited by Dr Stan; 10-13-2011, 02:50 AM.

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                    • #11
                      If its this vertical steam engine, March '46 pages 178 to 182, you will get away with, and its probably simpler too, to cast the cylinder solid and then bore it afterwards.

                      http://books.google.com.au/books?htt...page&q&f=false

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                      • #12
                        Originally posted by bob ward
                        If its this vertical steam engine, March '46 pages 178 to 182, you will get away with, and its probably simpler too, to cast the cylinder solid and then bore it afterwards.

                        http://books.google.com.au/books?htt...page&q&f=false
                        Thanks Bob
                        But it is the base shown in April '46 PS, that I am having problems with the core not the cylinder. Plus it is the porest drawing in the whole atrical.

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                        • #13
                          Oops - I got that "lost foam" idea backwards....sorry about that....
                          ----------
                          Try to make a living, not a killing. -- Utah Phillips
                          Don't believe everything you know. -- Bumper sticker
                          Everybody is ignorant, only on different subjects. -- Will Rogers
                          There are lots of people who mistake their imagination for their memory. - Josh Billings
                          Law of Logical Argument - Anything is possible if you don't know what you are talking about.
                          Don't own anything you have to feed or paint. - Hood River Blackie

                          Comment

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