42449Re: [hobbicast] ingate / outgate
- Jan 2, 2013FWIW 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
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
> --- On Wed, 1/2/13, Sage McGirk <freeflysage@...> wrote:
> From: Sage McGirk <freeflysage@...>
> Subject: [hobbicast] ingate / outgate
> To: email@example.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
> [Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
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