RE: Info about Zcorp & lost-wax method

From: KDenton@williams-int.com
Date: Tue Oct 26 1999 - 22:33:38 EEST


Bathsheba and all,

If your parts are going to be burned out via flash fire then enough oxygen
is the key to complete burnout. This is true no matter what the pattern
material is. As a general rule the more drain plugs you can add that will
act as air-vents allowing a complete burn the better you will be in the end.
We use our RP equipment for making both investment and sand castings and
once we dialed in the process have a 98% success rate with pattern burnout.
Other factors that you may want to consider before jumping in is proper
gating, shell firing(burnout), shell pre-heat, pouring temperature, and
areas around the mold where you will need to insulate to maintain a longer
melt phase then other areas. You may want to get in contact with a good
Casting Engineer prior to starting your project.

Karl Denton
Lead Engineer
Williams International

        -----Original Message-----
        From: Bathsheba Grossman [SMTP:sheba@bathsheba.com]
        Sent: Tuesday, October 26, 1999 2:21 PM
        To: rp-ml@bart.lpt.fi
        Subject: Re: Info about Zcorp & lost-wax method

        On Tue, 26 Oct 1999, ferrotto wrote:
> Hello Rp list,
> we have a 3d printer of Zcorp and we need more info
> about the lost-wax method associated wiht that printer.
> We want to use this method for alluminiun component in
> automotive engineering .

        My experience has been that investment casting doesn't work
perfectly
        with wax- and resin-infiltrated ZCorp models: the burnout is not hot
        enough to fully destroy the material. If your parts are shaped so
        that residue can be blown out of the mold with air after the
burnout,
        that helps a lot.

        That said, my parts aren't blowable and they're all cast with
        investment, so to some extent you can get away with it. I lose a
        percentage due to incomplete burnout, and I don't always get very
        clean surfaces, but it's still a viable method.

        Ceramic shell casting is said to work better. I had an art founder
do
        a couple of parts that way, and we had the same ash problem as with
        investment, but it wasn't what you'd call a controlled situation.
So
        that's probably not a good example.

        -Sheba
        Bathsheba Grossman (831)
429-8224
        Digital Sculpture
http://www.bathsheba.com

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