Model Builder

Heritage buildings preserved as miniatures

A few weeks ago I wrote about the 50th anniversary of the Futuna chapel in Wellington.  Ponoko lasercut the commemorative scale models of the building for the event, so we were very curious to know how it all happened because let’s face it, we don’t have many old interesting buildings in New Zealand, so this is a pretty big deal.  Surprisingly (because “astonishingly” may sound too dramatic) the ball started rolling because of a passersby curiosity.  The passer-by was Tony Richardson, and Futuna was the place he was passing by.

Tony’s visit to the chapel made a big impression on him as he struggled to understand “how the building worked, in particular how the lines of the roof planes related to the internal central pole and valley beams.”  His examination of the plans and photos was of little help, so he resorted to his kiwi bloke approach of wood+shed+tools.  All the marking and sawing resulted in a pile of wasted materials, rather than a beautiful model, so Tony started looking for a less painful way to make mistakes via an online laser cutting service.  It just so happened that Ponoko was mentioned in the business section of the national news.  Needless to say, the ball started rolling.

More about Tony’s fabbing under the cut:

Before he committed himself to something as complex in detail as the chapel, in 2007 Tony started with a simpler project designing a mail gauge for working out parcel rates.  This was in response to NZ Post revising their postage system without offering customers easy access to their plastic guides.  Tony dubbed his creation Alien for its ET-like aesthetic, lasercut a few out of ply and sold a bunch online.  Soon after NZ Post released their own guides made out of cardboard.

Tony’s area of interest is modernist architecture, and the Futuna model is one of several structures he’d created using laser cutting.  These are structural building models that help people engage with the object, as opposed to being exactly scaled architectural models.  The precise 1:100 scale isn’t an option with 4mm ply.  Tony’s vision is to produce a scale model series of significant New Zealand architecture.  He is especially driven by any projects that provide a social benefit at the same time, such as raising funds for architectural restoration, as in the case of Futuna.

The creative process behind these models is functional rather than expressive, as they are based on existing designs.  The challenge is interpret ing “the essence of the structure in terms of planes and volumes and materials”, and using that to “construct a model that is close to scale, robust and sufficiently detailed to capture the essential qualities of the original”.

Each project starts with a full-scale ground plan which guides standardization of the ways that pieces lock together.  This is essential to avoid errors.  The next task is “optimising the design for laser cutting to keep the cost down.” The designs are then cut out of poplar, which is a cheap fast-cutting plywood that is easy to bond.  Using a familiar, readily available material also makes it easy for others to assemble the laser cut designs.

What did you find challenging in your fabrication process? Where do I start? Visualising a 3D structure while you design it in 2D can be a challenge.  Calculating angles (apart from right angles) and curves is interesting.  Striking the balance between simplicity and accuracy is a challenge.  Managing charcoal is a complication at the making stage, because all those cut edges have charcoal on them that is keen to make its mark on a clean flat surface if you give it half a chance.  The 0.2mm loss of material in the cutting process has to be factored in.  Or not.

Prototying is absolutely essential.  I check everything, then I double-check and triple check. I print off a screen dump of the model and “assemble” it as a 2D representation.  Even then, I make mistakes.  I use Inkscape, which is very user-friendly but it has some irritating quirks, most of which I discovered after they had caused problems for me.

Working with just 4mm ply and 3mm acrylic produces its own challenges, but these are part of the game and I accept them as such. It would be nice to have thinner woods to work with.  But it’s a bit like every other aspect of life – if you have limited resources, you need to work more creatively to achieve your goals.

Getting colour onto acrylic has been an interesting technical challenge, now solved.  One of the most valuable by-products of the Futuna project was getting to meet Hawkes Bay designer Jacob Scott (the son of the architect), and working with him to develop ways of reproducing colour finishes on other materials such as polystyrene.  I have the sense that I am still only scratching the surface of what is possible with this technology.

Have you been surprised by anything in the Ponoko process: One of the things I have had to adapt to is that the two sides of laser cut Eurolite are not the same. The “face” side typically shows more scorching than the reverse.  This is an issue when the part cannot be reversed (for example when it has engraving on it), but in other cases there are ways around it: I design my buildings, and then I “flip” the design so that it is cut back to front.  This gives me nice clean face sides.

In general, I have been impressed by the consistency of finished product from Ponoko.  I have had the odd item where a square hole has only been cut on one side, or where an engraved line has printed on some copies in a run but not others; I guess even computers struggle with real life at times.  But on the whole I have got what I expect.  The major exception to this last statement is the attention that Ponoko pays to the files that are submitted, when I would have expected Ponoko to get on with the job of producing what I sent them.  But no.  I get an e-mail pointing out potential errors in my design and inviting me to fix them before the job is fabbed.  This intelligent approach has saved me quite a bit of money and I am very appreciative.

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