Thursday, July 9, 2009

Cool Tool: Cheap(er) 3D Printer Update

So to get a better idea of the performance differences between the Prodigy Plus and the new $14,900 uPrint from Dimension/Stratasys, I ordered the pepper shaker test part and compared it to one I printed on a Prodigy Plus. The white part was printed on the new uPrint, and the black part was printed on a Prodigy Plus.

The pictures don't really do it justice but the part printed with the uPrint has significantly better bonding between the layers and the surface finish is slightly smoother. I don't have a roughness gauge handy so I can't tell you exactly how much smoother.

The improved bonding between layer should have significant performance benefits, especially in terms of shear across the Z axis (up-down) where most of my part failures have occurred. Since the plastic parts printed using fused deposition modeling tend to act like anisotropic composite materials I would like to see tensile test data for each of the axes.

The threaded lid on the new part really works and seem to be much sturdier than the older part. The threads sheared off my old one when I tightened it too much. I wonder if there is a design guide for 3D printed thread forms.

This may be a useful alternative, since most of the time when I need to connect two 3D printed parts I will print 1mm pilot holes and drill them to size and tap threads into them. A drop of CA glue, after drilling out the pilot hole and before tapping, tends to help melt the edges of the hole together for a better thread form.

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