Amidst all the usual workshop sounds; the whirring of extractors, the rumble of machinery and 3 different radios playing 3 different types of music depending on where you are standing, there is a new sound that has entered the design realisation workshops. Only noticeable if you stand close enough, a curious and jovial little melody can be heard escaping the newest edition to the props department…the 3D Printer!
It looks like something from a sci-fi movie which is quite apt really because it can do things that definitely seem out of this world…
So what is 3D printing?
3D printing is a form of manufacturing whereby a computer rendered 3D image can literally be ‘printed’ in a fully functional 3D form. There are different types of 3D printers that use different materials and processes but our printer- the MakerBot Replicator 2- works by ‘printing’ layers of melted plastic to form a shape. The plastic, Polylactic Acid (PLA) is a bio-degradable polymer which is extremely durable but has a relatively low melting point of 200 degrees. When a 3D rendered image is sent to the printer in the form of a g-code, the printer heats a spool of PLA through a nozzle and prints layer upon layer of plastic onto the machine bed. The printer instantly cools each layer of plastic as it prints so that the next layer can be immediately applied.
One of the amazing things about 3D printing is that potentially, there are no limitations to what it can do, which is an especially exciting thought when mixed with prop making…as more often than not we are asked to create something out of the ordinary!
But of course we are just getting starting to learn about 3D printing and what is can do for prop making here at the Guildhall School. Here are some examples of what we have been up…
The printer can be used with a variety of software, the main ones being Sketchup and AutoCAD. Here is an example of a little tester project using an AutoCAD drawing that Edd created a while ago. These images show the process through from start to finish; from the original, real life kettle, through to drafting in AutoCAD, to the first attempt with a dodgy handle through to the manufacture of a much more successful mark II version.
The MakerWare software automatically creates a support for the item being printed- holding up any parts of the object that would otherwise be unsupported in the printing process. A good example of this is the handle. Because the printer creates the kettle in layers, without the support structure the bottom of the handle would be floating in mid-air and would therefore fail to print (this is what happened to Mark I!). So the support structure, the web-like cocoon around the unsupported parts, allows this process to happen. You can clearly see the parts of the design that don’t need the support and also you can clearly see the difference between the support structure and the smooth surface of the object being printed.
Another interesting part of the process is the internal structure of the kettle. The kettle was drawn in AutoCAD as a solid 3D object. The printer knows that the finished article needs to appear solid but it doesn’t have to actually print a solid. Instead, the software creates a mesh-like interior which gives the object the strength required to feel solid, without it actually being solid.
It’s all very clever and exciting!
We are still discovering what 3D printing is all about and what it can do for us, but it is clear that the possibilities are endless. So, next time you are walking through the Design Realisation workshops here at the Guildhall School, pop into the Props department and see what’s printing…