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 the unused powder can be retrieved.
- 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.
- Only the surfaces that form a closed object can be 3D
printed. The closed surface model has to be converted into a solid
object, which is described by the .STL file. Once you have a .STL file
please prepare .ZBD file and submit for the 3D printing.
- Create surfaces with no gaps (trim etc.).
- Unifty Normals of the surface of each object. Normals should be pointing away from the object.
- Wall thickness (dependent on the geometry): For very
thin walled parts normal engineering practices of adding ribs for
support or creating fillets or reinforcing edges and 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, this 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.
- The RPC only accepts the file format *.ZBD for 3D Powder Printing.
- You first need to have an *.STL file for preparing a *.ZBD. *ZBD files are created by importing *.STL files into the ZPrint software, available on all DAAP CGC machines.
- The *.STL or stereolithography format is an ASCII or binary file used
mostly in manufacturing. It is a list of the triangular surfaces that
describe a computer generated solid model. This is the standard input
for most rapid prototyping machines.
- You can use any program that
exports *.STL files. Proven programs that export *.STL files successfully are:
- Alias Studio Tools
Differences Between Z510 and Z310 3D Powder Printers
Build Size/Maximum Printing Area
Z510 - x10 x y14 x z8 inch / 254 x 356 x 203 mm
- Z310 - x8 x y10 x z8 inch / 203 x 254 x 203 mm
- Z510 - prints in full 24-bit color
- Z310 - prints in monochrome
- Because the Z510 uses a finer powder, it has a better resolution when compared to the Z310.
- Parts coming out of Z510 have a greater initial strength.
- If given
sufficient time to cure parts printed in Z310 will achieve the same
strength. Still, it is advisable to
print fragile and thin parts in the 510 to avoid breakage.
- Z510 - $3.50 per cubic inch
- Z310 - $3.00 per cubic inch
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
- 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.
Why *.ZBD's instead of *.STL's
- If the file is submitted as a *.ZBD then there should be no confusion in terms of the scale of the parts.
- Otherwise, there is a possibility that the part could be printed
in different units then those that the student intends.
Slicing the Part
- The ZPrint software allows the user to slice their part layer by layer, helping to ensure that there are no unexpected errors.
- The ZPrint software displays non-agreeing (inverted) normals as grayed-out surfaces.
- These can be manually flipped and corrected within the software.
- Inverted normals will not print.
- ZPrint allows the user to orient the part in the most efficient (minimum z direction) and least destructive (minimum chance of deformation along part's long axis) way.
- Within Zprint the user is able to calculate the price of the part.
- The cost can then be reduced by remodeling the part in order to consume less material/machine time (by shelling, scaling down,
- Reducing the cost also reduces your wait time for the part.
Receiving *.ZBD's from students saves
time and man power, which benefits the students by allowing the RPC to get more projects done in a shorter amount of time.