42450Re: [hobbicast] ingate / outgate
- Jan 2, 2013Found this link with some diagrams if anyone else is interested... (little
over half way down)
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
> 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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