Asteroids and minor planets

This evening’s session was hugely exciting! We had been set a task to bring in a small model to try out on one of the Maker Bots, so we started off by loading one of our own files onto the machine. The Maker Bot (pictured below) is a desktop 3d printer that prints using ‘Fused Deposition Modeling’ or FDM for short. It uses an extruder, which is similar in principle to a hot glue gun. Plastic filament is fed in through the top, is melted, and finally “extruded” out of a small nozzle into the layers that build a 3D print.’ [1]

Anatol, the course tutor explained thoroughly how meshes need to be prepared for print and loaded our models into Materialise Magics, an STL editing programme that can help detect and fix errors in 3d meshes and also outputs models into slices/layers that can be understood by the printer.

The picture above shows asteroid Bennu printed at just w18 × h13 × d15 mm – that’s 0.085% of it’s actual size (if my maths is correct!). I was surprised by the amount of detail and undulation in the surface that is captured even at this scale. Here it is displayed on a mirror. Mirrors are a key material in my practice – I reference them as highly scientific instruments used in telescopes and crucial to space imaging. I was interested to find out these NASA are created by radar astronomy. Even though a mirror is not used in this particular technology there is a nice link with the use of reflections: ‘Radar astronomy is a technique of observing nearby astronomical objects by reflecting microwaves off target objects and analyzing the reflections.’ [2]

While our models were printing we were introduced to stereo lithography and shown the 3d scanning facilities: another route for creating 3d files for printing. I will be attempting to scan a sculptural object over the next couple of weeks.

[1] Learn the basics of 3d printing, https://www.makerbot.com/learn/
[2] Radar Astronomy, https://en.wikipedia.org/wiki/Radar_astronomy

Today was a great start to the course. We were given a detailed tour of the 3d printing facilities at The Cass by course tutor, Anatol Just. We looked at the various machines – SLS (Selective Laser Sintering), Z Corp 3D printing, Envisiontec 3D printing and Makerbot 3D printers – and were shown samples of the materials they print with the types products they are capable of producing. The possibilities seem enormous. Anatol emphasised the link between material reality: it’s easy to get carried away with 3d modelling software and make something that looks very impressive on screen – but the laws of physics still need to apply if you want to print it!

Anatol had prepared a comprehensive introduction the history of digital manufacturing, explaining how it goes back to 1801 with the Jacquard Loom being the first machine to use punch cards to control the movements of a machine. This introduction also covered the .stl (Standard Tessellation Language) file – the most common format to work with in 3d printing (although some .obj and .3ds will also work). These files work with meshes made of triangles. The more triangles a mesh has, the higher its resolution.

Things are starting to make sense – it’s such a relief from spending hours looking at these files unguided. I’m excited to start thinking how I can apply this new knowledge and understanding to Asteroids and other minor planets.