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42450Re: [hobbicast] ingate / outgate

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  • Sage McGirk
    Jan 2, 2013
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      Found this link with some diagrams if anyone else is interested... (little
      over half way down)

      http://www.hnsa.org/doc/foundry/part2.htm

      /sm


      On Wed, Jan 2, 2013 at 4:11 PM, Sage McGirk <freeflysage@...> wrote:

      > FWIW I'm looking to cast something like the attached picture. Use the
      > center hole as a massive ingate and just drill it out perhaps?
      >
      > Thanks for the responses thus far
      >
      > /sm
      >
      >
      > On Wed, Jan 2, 2013 at 3:49 PM, David Patterson <odd_kins@...>wrote:
      >
      >> **
      >>
      >>
      >> You need to calulate the amount of time you need to fill the mold cavity.
      >> Then starting from the ingates calulate the size needed to fill the cavity
      >> in that time. Shape and number of the ingates will be dictated by the shape
      >> of the casting. The cross sectional area of the runner/runners will be
      >> equal to the sectional area of the ingate/ingates. The sectional area of
      >> the sprue(smallest diameter) will be 1/4 the area of the runner. But this
      >> is just a starting point, you adjust from here until you get a good
      >> casting. Don't forget to cut a pouring basin into the cope, about 3 times
      >> the diameter of the sprue. This is a 1-4-4 ratio used in non ferrous
      >> foundrys, 1 is the sectional area of the sprue, 4 sectional area of all
      >> runners and 4 sectional area of all ingates. Beyoud this trial and error
      >> until you find what works.
      >>
      >> The idea is to keep the sprue full during the pour, keeping turbulance to
      >> a minimum.
      >> Thin casting that don't require risers, vent, a lot if unsure. Risers
      >> will act as vents in larger casting.
      >>
      >> The only reason to have a second sprue(outgate) would be if you have 2
      >> people pouring at the same time.
      >>
      >> Dave Patterson
      >> odd_kins@...
      >> http://home.comcast.net/~oddkins/foundry_home.html
      >>
      >> --- On Wed, 1/2/13, Sage McGirk <freeflysage@...> wrote:
      >>
      >> From: Sage McGirk <freeflysage@...>
      >> Subject: [hobbicast] ingate / outgate
      >> To: hobbicast@yahoogroups.com
      >> Date: Wednesday, January 2, 2013, 11:09 AM
      >>
      >>
      >>
      >>
      >> Happy new year everyone! I've been hobbicasting for about 6/7 months
      >> now, and I'm looking for any sort of rule of thumb for the size of the
      >> ingate/outgate holes. I'm starting to cast some bigger objects (>
      >> 3-4") that tend to be fairly thin. I've learned to POUR faster to
      >> ensure nothing cools prematurely but find some objects still dont
      >> quite finish. I'm guessing larger ingates are the trick. I'm also
      >> about to embark on some gear shaped objects, and wondering how ,if
      >> needed, to do multiple sprue holes as I've seen with lost foam, but
      >> will be using wood as objects now. Any advice, video's, pictures
      >> would be appreciated
      >>
      >> Thanks
      >>
      >> /sm
      >>
      >> [Non-text portions of this message have been removed]
      >>
      >>
      >>
      >
      >


      [Non-text portions of this message have been removed]
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