While it has already
been mentioned elsewhere that a designer should focus design for
manufacturability on the eventual production process, there are
some simple factors that can be considered to lower the cost and
speed the production of SLA parts.
Z-height and part volume
drive up the build time - which correlates to a higher cost. It
is obvious how to minimize these paramaters. Given roughly equal
dimensions in x, y, and z, there is a third factor that can help
choose the best orientation.
scan density is increased near the outside walls of the parts, and
lessened for interior regions. As shown below, this means the amount
of time the laser spends curing the polymer is increased near the
Two slices are shown:
one from a part with a high volume to surface area ratio (Solid
Part), and one with a low ratio (Thin Wall). Even if the “Thin Wall
Part” has the same volume as the “Solid Part,” the build time will
be longer, due to the greater area of the dense scanning regions.
By orienting the part
to minimize the non-horizontal surface area, build times can be
reduced by up to 30 percent. This tactic is valid for any SFF process
- such as selective laser sintering - that spends more time processing
walls than interior slice regions.