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42449Re: [hobbicast] ingate / outgate

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  • Sage McGirk
    Jan 2, 2013
      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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