Hoist and releasing tong build

Discussion in 'Foundry tools and flasks' started by Melterskelter, Dec 19, 2017.

  1. Melterskelter

    Melterskelter Silver Banner Member

    I see that the photos upload in very low resolution—-sorry they can’t be clearly read The bars for the tongs are 1/4” thick. They have plenty of rigidity for the A20 full of iron that I routinely lift. Heat exposure in the furnace is brief enough that they never get hot enough to weaken.

    Denis
     
  2. Zapins

    Zapins Silver

    I'm going to weld up a copy of these tongs soon. I was wondering if you had any close up pics of the way you put the pouring cart together? I have an idea but it would be nice to see what you did as a reference.

    I got regular bearings that I will weld onto the outer casing.
     
  3. Melterskelter

    Melterskelter Silver Banner Member

    Happy to provide photos as needed. Just let me know. I am traveling right now. So, there might be a slow “response time” on my end. Both the trolley and hoist have proven themselves.

    One small trolley modification I am considering is to split the ring that holds the crucible. My new habit is to let the crucible cool outside the furnace while held by the trolley. If the ring is not cut, I worry it could put too much constrictive force on the crucible. So, for now I make sure the crucible is sitting on a support and not actually suspended in the ring as the crucible cools(after it initially transferred heat to the ring and thus temporarily increased the ring circumference). Might be needless worry, but I did notice the crucible to be pretty tightly held/wedged in the ring the one time I just left it suspended to cool.

    Denis
     
  4. Zapins

    Zapins Silver

    My tongs are nearly done but when I was testing them I found that they open just fine with the cable but when lowered around the crucible they do not grab the crucible with enough force to hold it. The tongs just slip open like one of those weak stuffed toy claws. How did you manage to make yours grip?
     
  5. Jason

    Jason Silver Banner Member

    add more quarters and try you luck again.:p
     
  6. Melterskelter

    Melterskelter Silver Banner Member

    After talking to Zapins and reviewing the photos I posted earlier in this thread I can see that it is not clear how the trapezoidal cage with rivets is constructed. If one looks at post 17 dated April 12 2018, you will see a photo that has a picture of the trapezoid and rivets are pointed out and has the words "Top of Tong." What is not clear from the photos or description is that there is a single piece of flat bar traversing the top of the trapezoid ending just shy of the tong bars and held in place by the two rivets each located just lateral to the attachment of the turnbuckles. That piece prevents the tong arms from being able to pivot toward the center and causes them to establish a grip on the crucible. I will try to make a photo of that portion of the mechanism in the next couple of days---as soon as I travel out to the barn 15 min from here. Arrrggh. I tried to include every detail of the construction in my photos, but missed that key point. My apologies.

    Denis
     
  7. oldironfarmer

    oldironfarmer Silver Banner Member

    I thought your description was fine. The bars are each supported by two points, the bottom of the frame on the outside and the rivets (I thought they were rollers) on the top inside. I figured Zap wasn't finished, which he isn't.
     
  8. Melterskelter

    Melterskelter Silver Banner Member

    993085E2-50A9-4B36-BB51-9F8310F90B20.jpeg B906BEE7-AD5F-4147-83C3-248273600436.jpeg Promised a month ago I finally remembered when I was at the foundry to take a top-view photo of the assembly that holds the lifting tong bars. I wanted to illustrate the piece of 1/4 x3/4” x roughly 5” piece that is riveted in place that prevents the tong bats from collapsing center wards as the assembly is lifted.
     

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