Die casting lead

Discussion in 'Die casting' started by 3Dcasting, Jun 12, 2021.

  1. 3Dcasting

    3Dcasting Copper

    3 years ago I got a call from a guy wanting some lead castings made. He saw my lead sinker molds and asked if I can cast some lead parts for him, 1000 or maybe 2000 per year. At first I declined but he offered to send me a sample and urged me to "look into it".

    The part is a security pin and is sold by the piece, not by weight as most lead products. Hence it was a very appealing offer. After some thought and some tries I ended up machining a small aluminum three part mold that can make 10 pieces. The mold was crude and didn't work so well but I managed to send some promising pieces to the customer.

    Machining a mold for a 3mm diameter and 2 cm length part with a drill press and a dremel is difficult so I scrapped the first mold and started over. I opted for two pieces per mold cycle this time with much more attention and taking enough time in between; probably finished the mold in a month. In the end I had a three part mold: two identical sides and one perpendicular to both. The end product is like a bolt without threads and a circular head.

    Anyway, I made the mold thinking that it needs a machine to be properly used. Hence I found on youtube plenty of videos of lead casting machines that seemed easy to copy and started my own.

    It is in operating condition since then with some minor tweaks. I made hundreds of parts usually in batches of 200 pieces. They still need some cleaning by hand for flashing though. The original concept has an electric melting furnace with a hole at the bottom to pour directly on the mold. My version of the furnace leaked badly and was removed. I now pour traditionally, with a ladle.
    I recently got a lathe and plan to repair the mold (or make a new one) and improve the machine overall. Hopefully this summer.
    oldironfarmer, Tobho Mott and Jason like this.
  2. Petee716

    Petee716 Gold Banner Member

  3. Jason

    Jason Gold

    Very cool. I love mechanical stuff that took some brain power to make.
  4. 3Dcasting

    3Dcasting Copper

    Yes, I built something that looks similar and sits on top. I was looking for pictures of the valve thing they have but found none.
  5. Petee716

    Petee716 Gold Banner Member

    If I recall correctly it's just a cone shaped plug with a lifting eye and matching seat. My friend has one. I can get pics and measurements if you want.

  6. 3Dcasting

    3Dcasting Copper

    Ahh I see. Thanks Pete. The one I made was very small and was poorly made, no wonder it leaked. I'll have another go machining a better one this time.
  7. Petee716

    Petee716 Gold Banner Member

    I got ahold of my friends lead melter and took some pictures. Maybe they will be helpful, maybe not.
    The entire well and spout appear to be cast iron. The rod goes into the truncated cylinder portion of the spout area at an angle of about 30 degrees from vertical and doesn’t actually fit tightly in the entry hole at all. It just covers the top of a .050” hole that goes vertically down through the cone. The wire lifting mechanism simply lifts the rod for about .5”, maintaining the rod’s angle. I suppose the leads viscosity prevent the lead from leaking when the rod is in the down position.
    631E609D-0E6A-4347-BF3F-7CC2C1DA9A5B.jpeg 1E24FEE5-2F31-435A-8D89-EC9267608127.jpeg 15A73671-021E-471A-A5E1-7198B0EA5739.jpeg 511D9DBD-75F9-491A-A111-F82CF6907BDF.jpeg
    The reading on the caliper isn’t clear in the photo. It’s .590”.
    The flow rate through the .050 hole is probably fine for musket balls and small sinkers but probably too slow for your purposes.

    3Dcasting likes this.
  8. 3Dcasting

    3Dcasting Copper

    That's very useful, thanks!
    Looks very simple and foolproof actually. I overshoot the hole when I did mine, it was maybe 0.10" or 2 mm and it was flowing like crazy even shut combine with the rod that was supposed to plug it. Need to take some photos and start redoing it sooner than later.

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