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How Was This Machined?

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  • How Was This Machined?

    Ever have one of those pictures that you've looked at a thousand times or more, but failed to notice certain things about it? I was staring at a photo of parts of the original mold for the Tucker's horn button, when it suddenly occurred to me that I hadn't the faintest clue as to how it would have been done back in the '40s. I know how one would do it now, with a CNC machine, but back in the '40s, with only manual equipment? I don't know.

    Here's a shot of the mold, showing the Tucker crest.



    Here's the back side, showing that it was machined out of bar stock



    The front of it is fairly elaborate and detailed, with the crest following the contours of the curve of the mold. So, any clues?

  • #2
    I will take a guess at a hand carved model and a duplicating head on a B'port type machine. A tracing stylus in one spindle and a power spindle in the other.
    Errol Groff

    New England Model Engineering Society
    http://neme-s.org/

    YouTube channel: http://www.youtube.com/user/GroffErrol?feature=mhee

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    • #3
      Something like an Alexandra 3D engraver, bit like a standard pantograph engraver but the head can follow a 3D pattern.
      Patterns would have been done 6 to 10 times size as any errors on the pattern do nor show on the mould.
      .

      Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



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      • #4
        How cool is that? An original piece of Tucker factory tooling!

        Edit. I think the penny has just dropped. Hence your recent post on melting aluminium? You probably know this, but wax investment is the way to go to accurately reproduce a detailed piece like this. Lots of info at alloyavenue.com or its predecessor backyardmetalcasting.com
        Last edited by bob ward; 11-24-2012, 05:18 PM.

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        • #5
          Its about the only piece left, too, I'm afraid. The original dies for the cars were made out of Kirksite (these were intended simply to be used on building the pilot cars and would have been replaced by more conventional material) and their whereabouts are uncertain. A couple of gentlemen bought up most of the dies and the incomplete bodies and parts, intending to build more cars, but never built more than a couple. The bodies and the tooling sat outside and were damaged by the elements. The final disposition of the remains isn't entirely clear. Some were sold, and its assumed that the rest were crushed, but the folks who actually know about these things have the annoying habit of being rather tight lipped about it all.

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          • #6
            I do not see what it is in the second photo that "shows it was machined out of bar stock". Although the explanations above are certainly possible, I would suspect it also could have been stamped like a coin.
            Paul A.

            Make it fit.
            You can't win and there is a penalty for trying!

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            • #7
              Many coinage dies were cut by hand which required extreme patience and skill.

              Banknote printing plates were similarly cut - but they were more difficult as all colors in the note had to have a seperate plate and all plates had to be correctly "registered" in relation to each other.

              Filigree work is similar as regards hand and eye skills and co-ordination.

              http://en.wikipedia.org/wiki/Filigree

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              • #8
                Originally posted by bob ward View Post
                How cool is that? An original piece of Tucker factory tooling!

                Edit. I think the penny has just dropped. Hence your recent post on melting aluminium? You probably know this, but wax investment is the way to go to accurately reproduce a detailed piece like this. Lots of info at alloyavenue.com or its predecessor backyardmetalcasting.com
                No, I hadn't planned on making castings of that. It's a little more complicated than my skill set, and I don't have access to the necessary tooling to be able replicate it (I'm certainly not about to attempt to hand carve it). Pouring aluminum has got me thinking about making more sophisticated things than I've been doing lately, which is what got me thinking about how they would have made that.

                I am going to try and replicate the Tucker ashtray given to dealers. There weren't that many made, and they generally sell for $1K+, which is way out of my price range.



                I've got a model of the car that's about the right size that I can use to make part of the mold, and much of the rest can be easily machined out of a block of wax on the manual mill we have at work. The tedious part isn't visible in that picture, but the car is on a bricked road (to represent the track at Indy), and the bricks are staggered, so I can't simply do one cut along the short section and be done with it. Still, it should prove an interesting challenge, and if I do it right, I might even be able to make a little extra money selling them.

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                • #9
                  I'm going to say that back in the day it was probably hand engraved / carved after the basic shape was turned and the face concaved or rounded.
                  Then it was used to either stamp or cast off of.

                  JL......................

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                  • #10
                    The horn button was cast or injected in plastic as I've seen photos of them and have a replica which was based off an original horn button (I don't know if it was made using that piece or not, and unfortunately the gentlemen was selling them has passed away, so I can't ask him about it).

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                    • #11
                      look at it with a really good magnifying glass and you will see how it was made..

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                      • #12
                        Well, I don't have access to the piece, only a photograph of it.

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                        • #13
                          I have been home casting for a number of years and I believe that would green sand cast quite nicely. I recently finished a project that was a bit similar to this - a no longer available name badge.

                          I have just finished up a restoration of a Sheldon lathe with the "Sheldon" name plate missing. I asked on the yahoo Sheldon site for info or pictures of the item, thinking if I had a pic and the dims I might could make up a casting. As typical on most forums, I quickly got help, several pictures and best of all, an offer from a member to send me the plate off his lathe to see if I could use it as a pattern or just use it to try to copy. The plate arrived and --- uh oh! its a thin stamping, much to thin to do a cast from. But with a little head scratching I loosely attached a 3/16" thin piece of wood to the back side and carefully trimmed to match the edges of the plate - I could cast this... I had 2 suitable flasks so I molded up both and got 2 really nice reproductions. Using these 2 and the original and the 2 flasks again, I got 6 more nice pieces. (there had been several guys on the forum wanting copies) The detail a good sand will reproduce is amazing - I once saw a picture of a piece that had picked up the guys fingerprints!. (I use Petrobond oil sand)

                          Hers a couple pics---

                          This is the original (in the center) and the 2 copies from the first pour just before close-up. The back side has 2 tabs about 1/4x1" for attaching to the lathe, I just pushed them into the sand and the imprint will come when I fill this with the sand.



                          This is my pouring 'station' - propane furnace, the 2 flasks closed up and ready to pour, the misc lifting tools, slag spoon, etc and a couple muffin tins for excess.



                          A close up of the front and back of the replicas



                          All of them lined up with a couple painted - getting the red paint in there was harder than making the pour! The original is on the bottom with the thin piece of wood used on the back side.

                          If everything seems to be going well, you have obviously overlooked something........

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                          • #14
                            Originally posted by Tuckerfan View Post
                            Well, I don't have access to the piece, only a photograph of it.

                            oh - sorry. --- my bad...

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                            • #15
                              Well, I don't have access to the piece, only a photograph of it.
                              OOPS, my bad too - guess you were typing while is getting the pics in -- oh well enjoy the pics anyway...
                              If everything seems to be going well, you have obviously overlooked something........

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