Appendix I
ZCast Design Guide - 6
3 ZCast
Advantages
Today, metal casting molds are commonly created by first producing a machined pattern (or
pattern set) that is then used to create the molds. Instead of utilizing this costly and often time
consuming process, the ZCast process utilizes 3D printing to print the molds and mold inserts
directly from CAD data. With the ZCast process, Z Corp. provides the option to skip the pattern
or tooling step, significantly reducing the time required to obtain metal castings while also
reducing the cost.
The production of prototype castings using conventional methods often can take several weeks
and be prohibitively expensive. These constraints often limit the number or preclude the
production of metal prototypes during the development process. Specific time and cost savings
will depend on the size and complexity of the desired part, but can be substantial for most
customer needs. Castings can be produced in as few as one or two days for a fraction of the cost
of traditional tooling.
3.1 The
Materials
ZCast 500 powder is a plaster-ceramic composite suitable for casting low temperature metals
(aluminum, magnesium, and zinc). Tests conducted by Z Corp. and it’s foundry partner (Griffin
Industries) have shown results that mimic traditional sand casting finishes and tolerances. Many
successful castings have been made in 356, 390 and 319 aluminum as well as zinc, bronze, and
magnesium.
The ZCast material set can be used on the Z
®
810 Large Format 3D Printer, the Z406 3D Printer
and the ZPrinter
®
310 3D Printers.
3.2 Design
Freedom
In addition to reducing the time and cost to create a prototype casting, the ZCast process also
provides the freedom to produce complex castings that previously were difficult or impossible to
produce using conventional tooling methods. One of the powerful features of the ZCast process
is the freedom to incorporate undercuts and channels in the molds. Runners and vents can be
formed inside the mold that are otherwise impossible to machine; cores can be integrated into the
mold, minimizing the number of parts and simplifying setup. For prototype parts, this greatly
simplifies the mold design process.
Design alternatives include:
•
The Direct Pour Method
involves printing an entire mold, cores and all, in the ZCast
material. This usually uses the most material, but allows for virtually no set-up time and
very quick production of your prototype casting.
•
The Shell Method
involves printing only a thin (½ inch thick) mold to surround the entire
part. This shell is then backed with traditional foundry sand in a flask to create a mold
suitable for pouring. This helps to minimize the amount of ZCast material used and is
particularly useful for assembling large molds that are too large to fit in the build volume
of the Z Corporation printer.
•
The Combination Method
involves printing cores with ZCast material and using them in
conjunction with a conventional sand mold. Either the sand mold can be created with
machined patterns, or, to keep the time to casting to a minimum, the patterns can be
printed on a Z Corporation 3D Printer using zp
®
100 series materials.
