Reinforcing 12 Inch deep pattern for green sand?

Discussion in 'Sand Casting' started by Mark's castings, Oct 9, 2021.

  1. Melterskelter

    Melterskelter Gold Banner Member

    So, Mark, if you set that pattern on the counter and measure included angles between the counter and the front and rear surfaces, do they sum to more or less than 180 degrees? I can’t tell for sure in the pic, but it looks like less than 180 and to pull should be 184 or more. If less than 183, then I’d suggest converting the short face to a loose piece so that the main body of the pattern can be drawn followed by drawing the loose piece. Not hard to do. If 184 or greater, you are golden as is.

    Denis
     
  2. Hi Denis, here's the angles as it currently stands, so there is a combined 6 degree taper between the two faces when taken together. I'm hoping to withdraw the pattern at a slight angle from vertical.
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  3. Melterskelter

    Melterskelter Gold Banner Member

    Thanks, Mark. That should work great. In my post above I was measuring the angles from the counter to what would be the visible surface of the pattern so that on the short face I would state that angle as 100 and on the long face as 86 for a combined 186.

    Denis
     
    Mark's castings likes this.
  4. Got the final touches on the motor mount pattern complete, coated it in graphite and made a sand mould. There's some shrinkage in the last area of the casting to fill (and solidify) and some issues with the finish from the green sand being too wet but it's a good casting!.

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    Tobho Mott, Melterskelter and Al2O3 like this.
  5. Melterskelter

    Melterskelter Gold Banner Member

    Nicely done, Mark. You cast this with the mold oriented as the part is shown in the bottom photo? How dare you post pics without the gate/runner setup in place? ;-)

    Denis
     
    Petee716 likes this.
  6. It was cast upside down with a thin flat runner feeding each of the triangular fins from the rear, the runners were offset slightly so the metal didn't immediately fall to the deepest part. The reasoning was to fill the thickest fins first and hide any possible shrink defects in an area not visible in the completed item.

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    Last edited: Feb 1, 2022
    Tobho Mott likes this.
  7. Been busy making and casting the cover for the drive belt and motor pulley, the pattern is another matchplate and took a bit of thinking to get draft on the pattern and also match the draft taper of the motor base casting.
    I machined the motor pulley today so the project is getting close to the end, there are six castings all told so far.

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    Tops, dtsh, DaveZ and 3 others like this.

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