Thanks for help; [rp-ml] Sand core prototypes

From: asrp <>
Date: Fri May 14 2004 - 07:17:42 EEST

Thanks to all of you for sharing your ideas. As Larry mentioned we have
decided to make core masters on our FDM m/c and contacted the local foundry
to make the epoxy tooling for sand cores. Because of urgency of project I
apologise not to get quote all who contacted me offlist but bookmarked them
for future projects.

Once again this listing is great resource for ideas otherwise no way you can
collect all that information from single media. Wish one day someone will
organise all rp-mail archived messages and publish as a book (suppose
excluding spams & scams). I'm sure that'll sell like a hot cake and will be
enough revenue for the RP-mail admin to put a world class spam filter.


----- Original Message -----
From: "Blasch, Larry" <>
To: "'asrp'" <>; <>
Sent: Thursday, May 13, 2004 10:03 PM
Subject: RE: [rp-ml] Sand core prototypes

> Rick,
> If you are making 30-50 of the same sand core part, than just build the
> prints with any accurate RP process and make high temperature epoxy core
> boxes to form the sand cores in.
> I do aluminum sand casting pre-production patterns often with SLA for
> quantities like that. I've also made tools for casting bronze, iron, steel
> and stainless the same way. It also works well for "Green Sand" molding
> no cores are required.
> Just build the patterns for sand casting -split at the parting line with
> dowel pin holes already in the parts. Use the pin holes to match drill the
> plate and this will guarantee that the pattern halves get mounted to the
> mold plate accurately. Unless you plan on making more than 100 parts, you
> can run SLA patterns in the sand without duplicating the plate. Glue the
> pattern halves to the plate, and rig gates and runners as necessary. A
> coat of epoxy spray paint will help the sand pull clean.
> I've run SLA "Master Patterns" with double shrink and used them to cast
> production tooling plate. That was in the distant past, now we just NC
> machine the production plate if we need 100+ quantities.
> The same goes for core prints. Depending on the core sand process you are
> using, you may be able to just build the core box with RP and make the
> directly. I never tried it with the newer "High Temperature" SLA resins,
> you may even be able to make shell cores in SLA core boxes.
> I've found that most pattern makers won't have any problem working with
> "accurate" RP masters. Typically, I just add a single shrink to the
> and no shrink to the core.
> Sincerely,
> Larry Blasch
> Design Engineer/CAE Systems Administrator
> OPW Fueling Components
> P.O. Box 405003
> Cincinnati, OH 45240-5003 USA
> Voice: (513) 870-3356
> Fax: (513) 870-3275
> -----Original Message-----
> From: asrp []
> Sent: Wednesday, May 12, 2004 12:59 AM
> To:
> Subject: [rp-ml] Sand core prototypes
> Hi,
> We looking for some resource/advise for making sand cores for =
> Aluminium castings. We have tried SLS sintered sand cores but process =
> seems to be very expensive. We need at least 30-50 pieces. Has someone =
> tried Zcorp machine to make the sand moulds? I'm keen for getting few =
> ideas and technologies available, because it will be an ongoing process =
> for us. Thanks in advance.
> Regards
> Rick =20
Received on Fri May 14 17:23:46 2004

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