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Antique machinery repair, appearance and originality.

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  • #16
    Everybody is a weldor
    until the REAL weldor shows up.

    Saw this on a tee shirt.

    LOL LOL LOL

    -D
    DZER

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    • #17
      Originally posted by Doozer View Post
      Everybody is a weldor
      until the REAL weldor shows up.

      -D
      You know what I told the HR guy that hired me?
      I said "Lots of guys can show you how to weld. I'm the guy that can tell you why to do it in a certain way".
      It helps to know some chemistry and physics, we were taught that as part of our training at Airco.
      Remember them? Yeah tha's where I got mine.
      25 miles north of Buffalo NY, USA

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      • #18
        Didn't you take some college level material science course ?
        I thought you mentioned that at one time,
        DZER

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        • #19
          Originally posted by Doozer View Post
          Didn't you take some college level material science course ?
          I thought you mentioned that at one time,
          Not that i recall, but the Airco training had a bunch of materials and design. I *did* do the machining and solidworks course at Erie community.
          25 miles north of Buffalo NY, USA

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          • #20
            Solidworks rocks.
            Fukin ahhhyy right.

            -d
            DZER

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            • #21
              Originally posted by Doozer View Post
              Solidworks rocks.
              Fukin ahhhyy right.

              -d
              I actually joined the EAA so I can take a refresher course and get certified in it.
              25 miles north of Buffalo NY, USA

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              • #22
                Originally posted by alanganes View Post

                ............ as the metal cools and shrinks.

                Now if you stuck the parts together and then encased them in a ceramic like used for investment casting, then maybe it could work. I don't know enough about the chemistry of molten metal to have any idea how much the metal composition might change if remelted and then just left to re-harden.

                Interesting thought, really.
                I think the first line above tells the story.....

                Your end result is probably going to have some issues, and it may not be the same size as the original. In some ways it DEFINITELY will not be unless you do some prep (that may or may not work)..

                Shrink rules are used to measure patterns for a reason.... shrinkage.

                Many people seem to think the shrinkage is somehow in the solidification. and there will be something then. But the real deal is what happens as the part cools from melting temperature (solidification temp) down to normal environmental temps.

                When you start at normal temp and size, then as you heat up the solid part, it is going to GROW. if the mold can accept that, then it may actually kinda work. The part will expand in reverse to shrinkage, ending up at about the size of the pattern just as it melts.

                If everything were perfect, then it might replicate the part, as the expanding part might make the mold expand to the part size, and allow the same size to be replicated. I don't think it would actually work out like that, but there os at least theory to say it could.

                The mold would have to allow it.... sand could, ceramic maybe not, depending on the expansion coefficients.

                But, YOU DO NOT WANT THE PART THE SAME SIZE. The part you have is fully machined, the part you WANT is as it came from the mold, with excess to machine to the size AND FINISH you have on the part. The mold won't replicate that well, although some types might be close, but short of what is needed in many cases. In some cases, whereas-cast surfaces were OK in the part, they still will be.

                You surely will have to add material in some locations for many parts, which is hard to do.... you'd have to add CI in the shape you want. It has to be something that will either vanish, or get used again, preferably the latter.

                I think you would need to add material to fill sprues just to take care of material losses, as well as to supply the pressure mentioned.

                You'd be better off to use the part to make a pattern, with wax, or clay etc to build it up to the pattern size. Then you'd still have it if something goes wrong, and it would be far easier to get the correct build-up over machined surfaces, etc.

                It IS an interesting idea, and as I mentioned, it has theory behind it to an extent. I think there are issues in actual practice that make it not so good a plan to actually attempt.
                2730

                Keep eye on ball.
                Hashim Khan


                It's just a box of rain, I don't know who put it there.

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                • #23
                  X2 what JTiers said. You would be better off to use it as a pattern, send it to someplace like Windy Hill Foundry and have them duplicate it. They'll add a quarter inch of thickness everywhere and probably 7 deg of casting draft. You'll have an as-new part when you get done machining it. It will be difficult to tell it from the hundred-yr-old original. Most likely the job would be cheaper than you'd expect.

                  Only other alternative is to do a weld repair as I outlined earlier.
                  There *is* metal stitching, but that runs into real money -- link here: https://www.metalockengineering.com/...tal-stitching/
                  25 miles north of Buffalo NY, USA

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                  • #24
                    That all makes sense - I did not think about the part growing under heat - pushing the form out and then collapsing a little within --- that's even like alanganes stated "if" you could keep the form from leaking... so using it as a mold form sounds best for sure - and you don't need to heat up an entire structure - sometimes what seams like would be a shortcut would take much longer... and have worse results... i think this one of those times.

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                    • #25
                      Originally posted by nickel-city-fab View Post

                      Not that i recall, but the Airco training had a bunch of materials and design. I *did* do the machining and solidworks course at Erie community.
                      That name brings back memories, back in the late 80's there was a boom on locally and a sharp increase in demand for welders and welder/fitters. Twice an hour on TV was this ad and another one that had a pretty girl singing a jingle " If you take pride in what you do, Airco Technical Institute"

                      https://www.youtube.com/watch?v=JewFVPZt-lQ
                      I just need one more tool,just one!

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                      • #26
                        David is one of these similar to yours,pic is from 1920 Fairbanks Morse General Catalogue? Click image for larger version

Name:	8788C320-5401-4320-8484-4E21B33E587F.jpeg
Views:	100
Size:	3.49 MB
ID:	1945782

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                        • #27
                          Originally posted by David Powell View Post
                          I have just bought an ancient power hacksaw, a Perfect Tool Co no 3 built in Galt Ontario.
                          I intend to use the machine, but also to make it somewhat of a showpiece.
                          The vice has some damage to the casting where the screw fits the moving jaw and the screw, while fully able to close the vice does not pull it open due to the missing piece. An earlier welded and again broken repair is evident.
                          I seem to have two courses of action here, spend a lot of time and effort making an "invisible" repair which would likely somewhat weaken the casting, or make a visible neat looking period correct repair( No allen head screws visible).Leaving it at full strength.
                          Are there any suggestions as to what I should do?
                          I do not intend to resell the machine, but do wonder how my choice might affect its subsequent value,
                          Regards David Powell
                          Hahahaa! David Powell is top notch in my opinion. JR
                          My old yahoo group. Bridgeport Mill Group

                          https://groups.yahoo.com/neo/groups/...port_mill/info

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                          • #28
                            Originally posted by wierdscience View Post

                            That name brings back memories, back in the late 80's there was a boom on locally and a sharp increase in demand for welders and welder/fitters. Twice an hour on TV was this ad and another one that had a pretty girl singing a jingle " If you take pride in what you do, Airco Technical Institute"

                            https://www.youtube.com/watch?v=JewFVPZt-lQ
                            Yep, that brings memories
                            25 miles north of Buffalo NY, USA

                            Comment


                            • #29
                              Yes, It is similar to the one in the upper right corner of your catalogue page400 AND it bears a plate saying sold by Fairbanks Morse Canada
                              I would hazard a guess all fasteners were built " In house" as they are not quite standard sized.. or threaded. and more confusing still
                              there are some 1/2in by 12 tpi and some 1/2in by 13 tpi !!!!!
                              The cast main frame is warped, quite uniformly, about 1/4 in over its length.
                              The blade holding frame.s cast iron pivot holes were worn about 3 thous, but the steel pin they pivot on was hardly worn a thous.
                              I have got the electrics functioning, they are an obviously later, but maybe not much later addition. The totally open knife switch on the 110 volt circuit is part of the mechanism to stop the saw when the cut is finished.
                              The motor is a Century 1/3 hp DC job, it weighs a lot!!!
                              The only remotely modern appearing part is the rectifier which is properly and neatly in unit with the variac.
                              Some gears are set screwed to shafts, with deep dimples, some parts attached by taper pins through the shafts.
                              It would appear that some previous users did not possess or use oil cans!!!!
                              This time round I will make her fully functional and use her in my basement shop to see if we become friends, if we do maybe she will get a full restoration, paint and all.
                              Regards to all David Powell.

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                              • #30
                                Originally posted by David Powell View Post
                                I would hazard a guess all fasteners were built " In house" as they are not quite standard sized.. or threaded. and more confusing still there are some 1/2in by 12 tpi and some 1/2in by 13 tpi !!!!!
                                These fasteners may be the very old wire gage sizes. I restored an old upright steam engine from the 1880s about 15 years ago and found most of the fasteners to be odd diameters and thread dimensions, e.g., the largest were around 0.275" at 18TPI; many had slightly varying diameters from 0.265 to 0.272 at 20 TPI, and so forth. This steam engine was one of the many offered at the time as an easy to build kit for farmers and such, so I would bet that the fasteners were supplied with the kit, as most would not have the capability to make their own. I eventually found a wire gage screw chart, I believe in my old Machinery's Handbook 14th Edition, 1951, but could not locate it this morning. The wire gage sizes there matched my fasteners.
                                Dave Dalton

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