Troubleshooting a Shapeways Print

April Fools’ Day (愚人节) has come and gone and, to the Internet’s credit, most folks weren’t taken in by my last post, Printing With Steel on the PrintrBot Simple. Good on you, clever people.

But now the blog post just lurks there, context-free and malignant, a coldly crystalizing piece of unexploded Internet ordinance, waiting to disembowel the unwary traveler who pays no heed to timestamps.

Also! Faire Play’s funding period is winding down and only a scant five days or so remain before pre-production on Barbie’s parade armor is set to begin.

Shapeways managed to deliver the first metal proof of one of Faire Play’s backer rewards ahead of schedule! I was expecting this steel Aegis Pendant to arrive after the funding period, but we got a little lucky this week.

Here it is, printed in polished gray. I’m impressed with how well Shapeways was able to reproduce the meandros motif on the shield’s face.

pendant

I’m a little less enthused about the stepping patterns on the gorgon’s face, but I think I know how to fix it. First, a simplified explanation of how 3D printers do their thing.

Hobby 3D printers and Shapeways printers’ work on basically similar principles. First, 3D models are digitally sliced up into multiple layers from bottom to top. A print head traces a pattern on an XY plane for each layer, either putting down a thin bead of hot plastic or sintering tiny particles of steel powder into a solid form.

Once the XY pattern for the first layer is completed, the printer moves up one layer and repeats the process.

unforeseen problem The moiré patterns on the gorgon’s face are an artifact of the printing process. If you look carefully you’ll see the divisions between layers, like elevation lines on a topographic map.

macro

Rotating the model 90° on its X axis might mitigate these artifacts. I’m fairly confident that the face of the pendant will be smoother if Shapeways’ printer prints the pendant as if it were balanced on its edge rather than laying on its back. This kind of edge-on printing isn’t possible with a hobbyist 3D printer, but shouldn’t be any problem when the developing print is suspended in Shapeways’ matrix of steel particles.

I’ll check with the gurus at Shapeways and see if this is possible, or if they’ve got some kind of auto-orientation function in their printing software that I can’t do anything about. #staytuned

One thought on “Troubleshooting a Shapeways Print

  1. tom burtonwood (@tburtonwood)

    i think this will work – i print a lot of my big flat panels like this – edge on – if i can – much better way of dealing with the details – of course this requires support material but it works just fine 99% of the time

    Reply

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