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Summary
Advantages of 3D Powder Printing
- Objects with negative space and undercuts can be printed out.
- Due to the pressure of the surrounding powder in the print bed, no printed support structures are necessary.
- Voids created by shelling parts must have access to the outside so that unused powder can be retrieved.
How 3D Powder Printing Works
- First, the 3D Printer spreads a thin layer of powder.
- Second, an
ink-jet printhead sprays binder throughout the cross-section of the part
being created.
- The build piston then drops down, making room for the
next layer, and the process is repeated.
- After the print, loose powder is dusted and cleaned from the finished part.
Expected Results
- The resulting material is very brittle with no tensile strength.
This must be considered during the modeling process.
- The printing
quality depends on the 3D powder print machine's layer thickness, which is set at 0.004 inch intervals.
- Deformation of the form is possible, depending on the geometry of the
part and its orientation.
- 3D printed objects can be finished by sanding, using filler, applying primer, epoxying, and painting.
- Epoxy Infusion for 3D Prints
General File Preparation
- Only surfaces that form a closed object can be 3D
printed. The closed surface/polysurface model must be converted into a solid
object, which is described by the *.STL file.
- Create surfaces with no gaps (trim, etc.).
- Unify the Surface Normals of each object. Normals should be pointing toward the exterior (non-printed space) of the object.
- Wall thickness (dependent on the geometry): For parts with thin walls, normal engineering practices of adding ribs for
support, creating fillets, reinforcing edges, and/or minimizing spans
should be used.
- Wall thickness should not be less than 1/8 inch.
- Reduce cost: Parts should be shelled and have the voids connected to the outside so that we may reclaim and recycle the powder.
- Fitting parts: Very thin or spindly parts should be
constructed from a different material as they are vulnerable to break.
- When parts are designed to connect to a 3D printed model, the 3D
printed model should incorporate a mating socket or groove. Users must
offset mating walls negative 0.010 inch per occurrence, (the part
expands by this amount during the printing process).
- Scale: Be aware of the scale and units of the CAD model.
Detailed File Preparation
The RPC only accepts the file format *.ZBD for 3D Powder Printing. *.ZBD files are created by importing *.STL files into the ZPrint software, available on all DAAP CGC PC machines. The *.STL or stereolithography format is a list of the triangular surfaces that
describe a computer generated solid model.
STL Instructions

Autodesk 3ds Max

Autodesk Alias 2010

Google SketchUp Pro 7

Rhino 4

SolidWorks 2010

Autodesk Maya 2010
ZPrint Instructions
More Help
3D Powder Print Surface Finishing
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