User manual

Appendix I
ZCast Design Guide - 28
6.11 Pouring Sleeves & Risers
A pouring sleeve is a tapered cylinder made of a refractory material with a ceramic filter at the
base. The filter is removable, so the pouring cup can be used as a riser as well. There is no
requirement to use sleeves, but the convenience is an advantage.
Pouring sleeves are inexpensive, come in several sizes, have a variety of filters available, and
work well with ZCast molds. A conical seat should be printed in the mold to accommodate and
position the sleeve. The sleeves should be attached to the ZCast mold with a foundry adhesive or
core paste. For safe measure, they can be clamped or wired in place to prevent shifting during
pouring.
Additionally, you can design a pouring sleeve to be integrated as part of your ZCast mold. Be
sure to make allowances for filter insertion to help alleviate impurities when pouring.
CAUTION
Pouring sleeves attached to the ZCast mold with core paste
may shift while pouring molten metal into the mold. Leaking of
molten metal may cause personal injury. Attach sleeves with
clamps and securing wires as needed.
6.12 Chills
Chills will be familiar to experienced foundrymen. The purpose of a chill is to help rapidly solidify
the molten metal in a portion of a casting. Controlling the solidification rate in this manner helps
to control the grain structure; keeping a tight, fine structure. The result is a sound casting with a
uniform distribution of the alloying elements.
Chills can be used in ZCast molds in much the same way they are used in traditional sand
casting. While they can be complicated, externally cooled components, they are often as simple
as steel or iron blocks which can be inserted into cavities designed (or cut) into a ZCast mold.
6.13 Printing
For general printing techniques, you should refer to the User Manual for your 3D Printer and the
ZPrint System Software Manual.
• When choosing your powder type (in “3D Print Setup”), simply select ZCast
501 from the
powder list (it will show up on the list for any printer that is capable to use the powder
system with the proper upgrade). The proper settings for saturation, layer thickness and
scaling factors are already set for you.
• Using “Bleed Compensation” is recommended. This will improve the accuracy so parts
will fit together better
3
.
• Orient parts so that the most critical faces are facing up in the build. For example, when
possible, put the outside of the mold components (non-molding surfaces) facing down in
the build. Under certain conditions, a slight arching
4
effect can occur on the bottom
surfaces in the build.
• When cores are being printed, you may choose to build a fixture underneath it. This will
improve the accuracy for critical fit items. Refer to the ZPrint Manual for instructions on
using fixtures.
3
See Table 1
4
Arching is a concavity phenomenon that occurs as moisture evaporates from the first few layers of a part that has been
printed.