A quick summary of your career?
I matriculated in 1968 to read Maths and my working life has always been centred on computers in technical fields. I spent some time in industrial research, then as an independent consultant, then at the University of York and, lastly, in embedded automotive software. I have always been a hacker at heart. If it says ‘programmable’ on the box, I will buy it.
How did you become interested in 3D printing?
About 25 years after graduating, I took up pottery evening classes. It is not surprising that I concentrated on geometric slab pots and was always seeking more precision than a hobbyist can achieve in ceramics. After retirement, we built a ‘super-shed’, but instead of the kiln I originally planned I bought a kit for a 3D printer. I made the kit up in a week or so and then spent a long time tinkering with the many software settings on the machine itself and getting to grips with the software workflow from design to finished article.
Compared with pottery, the 3D printer is reliable, reproducible and fast. I’ve made models of a few buildings, starting with ‘sketches’ of local landmarks (York Minster and our Millennium Bridge) and moving on to more faithful models of the Juno Beach Centre in Normandy and my workshop at home (with, of course, a scale model of the printer itself).
What prompted you to design a model of New Court?
An invitation from the College to a fiftieth anniversary dinner gave me the idea. When I received the invitation, I was at first shocked by how much time had passed and then pleased to be seeing old friends. It is always a pleasure to revisit College and I had lots of opportunities in 2000 when my elder daughter Frances went up to read MML. She got married last year and in my father-of-the-bride speech I was pleased to welcome many of her Johnian friends. I lived in New Court for two years as a student and view it as one of the most iconic of all Cambridge college buildings. It seemed like a perfect challenge for the 3D printer.
How did you go about designing the model?
On the web I found lots of photos and Google Maps’ ‘satellite 3D’ view is similar to having a virtual drone fly around the building. One very useful high-resolution photograph came with its own horizontal reference level as it was taken during the floods of 2003. It turned out to be by the College’s biographical assistant, Paul Everest. So: thank you, Paul.
Heights were tricky to pin down, but a detailed map from 1886 with a scale gave a distance reference. From these, and lots of spreadsheets and scaling factors, I was able to determine the external measurements of the staircases and cloisters and the architectural features such as windows, pediments, stringcourses and parapets. I made a mistake by starting to model the building as a collection of cuboids, which is fine for staircases C&D, F&G, H, I and J — but where A and B follow the curve of the river, a more general extruded polygon approach was needed. Many hours, and some 40 versions later, I was happy that I had all the details that I could reasonably print.
What is the actual printing process like?
The printer can only print one colour at a time, so the buildings (in ‘bronze’) and the roofs (in ‘silver’) need to be printed one after another and then glued together. The scale is a compromise between printer dimensions, the print time and a required detail resolution. As it is a late-Georgian building, I settled on a scale of 1 inch to 1 chain (1:792) and I coded these dimensions into a ‘program’ for OpenSCAD — a free ‘constructive solid geometry’ package. The model itself is 120mm by 64mm, stands 34mm high and takes about 6 hours to print: 3D printing is faster than clay, but you still need patience!
What’s next for you and your printer?
I took a lot of photos of New Court on the lovely sunny morning after the fiftieth anniversary dinner, so I can now fix a few minor errors (which only I know about). I want to print a legend recessed into the base and maybe look at using an even finer nozzle to include more details such as the drainpipes and window mullions.
I have a nearly-finished model of a 1970s block of flats, just along the coast from Juno Beach, and I have started collecting documents for a model of the Château d’ Annecy in Haute Savoie. There are also a lot of art-deco 1930s buildings (think Odeon cinemas and David Suchet’s Poirot) which would look really good. So, there is no shortage of projects. However, our family recently expanded with the addition of twin grand-daughters and my first priority will be visiting them.
Some technical details
The printer is a Kossel XL (a free, open-source design), which is based on a ‘delta’ symmetric configuration rather than a more usual XYZ Cartesian arrangement. The plastic filament is PLA (Poly Lactic Acid), based on corn starch. For finest resolution, the model is printed with a 0.25mm diameter nozzle and a layer height of 0.2mm.
Do you have a 3D printer and want to print New Court? Find more details, including the design, on thingiverse.com.