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Pushing the Limits of 3D Printing: Large Fragile 3D Prints

We all know that is possible to design and make the otherwise impossible with 3D printing: to 3D print incredibly detailed items that are light as air, with thin wiry structures, multiple internal cavities and complex, interlocking moving parts with minimal clearance.  Although it may be possible to 3D print such items, they do not always survive once they are removed from the 3D printer, cleaned, packed, and shipped around the world.

Shapeways 3D Printed Stag Wireframe

Recently Shapeways community member Dotsan designed an amazing Stag Wire 570mm that used the full size of our largest Nylon (WSF) 3D printer. We did manage to print two of these for Dotsan, but the model was so fine, with 1mm wires for such a large object it failed during printing and broke during post processing, so it took us multiple prints to get it to survive. We then packed it very, very carefully and shipped it to Dotsan with our fingers crossed, hoping that it was not damaged in transport.  

Fortunately, the 3D prints were delivered to Dotsan intact, as he shared in his very impressive unboxing video. Unfortunately, the risks involved in printing, post processing, packaging, and shipping the item are too great and we have asked Dotsan to take the design down from sale on Shapeways to ensure his customers don’t have a negative experience.  This is not something we wanted to do, we struggled and debated internally about the ramifications of this, but in the end we were forced to take this action for a number of reasons, the two main issues are:

  • The cost of such a large, wiry model with very little mass does not match the actual cost of 3D printing, especially as the model is prone to failure at any point along the supply chain so we would have to reprint multiple times. 
  • When a model of this size fails and we need to reprint, it will consume capacity and delay all other models in the queue, especially large ones.

We need to look at how we address the pricing structure to account for large wiry models such as this in the future. We could look at them on a case by case basis, which could slow down the production of large models, lead to rejections after acceptance if they are too fragile and add a degree of unpredictability. Or we could address the pricing structure at Shapeways to better reflect the actual the cost of 3D printing.

At the moment, we only charge for the amount of material used and not the overall size (bounding box) of an object that we 3D print.  The size of an object DOES influence the actual cost of printing.  If we were to bring the bounding box into the pricing equation, it would make some thin, wiry 3D prints more expensive, but it would reduce the cost of many 3D prints that are thicker, with greater density.  Thin wiry models are more prone to print failure, damage during cleaning, post processing and shipping so there is additional cost (and delays) when we need to reprint a model.

We already offer a volume and density discount on Nylon (Strong & Flexible) materials. For models that have greater than 10% density (material volume divided by bounding box volume), after the first 20 cm3, the remaining volume is calculated with a 50% discount. 

Perhaps we need to incorporate the bounding box into the pricing equation on all models to better match the actual cost of 3D printing and incentivize designs that are less fragile and more reliable?

We would love to know your thoughts about bounding box being added to the pricing structure and how it would it change the way you design.

About me
Shapeways Designer Evangelist
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