Sydney Harbour Bridge: CNC Laser to Router File Conversion 1

As you may be aware, I designed a laser cut Sydney Harbour Bridge a while back on CNCKing.com that was very well received and made it into several events over the past few years. It was great fun to design but once I got my ShopBot Desktop… I realized that this model just wasn’t going to be possible with it for two reasons.

1) The tolerances are way too tight for a CNC table router – where a laser removes 0.2mm of material, a bit does a lot more WHILE touching the material (wood in my case) which causes sheering and ripping across the model. Basically, the way the project was designed, the table router would rip it to pieces in the process of cutting it.

2) I don’t have the surface area – the largest thing I can cut comfortably with my CNC table router is 400 x 500 mm which is fine for most things but I need that almost doubled to make the spans. The problem with this is that I can’t cut the spans in half (in the middle) as it would look horrible and remove so much strength from the model I’m guessing it would fall apart on its own. Indexing is the solution… something I’ve never done before but will have to learn.

Yeah, I know… I took artistic liberties around the end of the video but still great fun! As I did with the Eiffel Tower where I documented and blogged the entire process from start to finish – I will do the same for this bridge.

This is the first time that I convert a file digitally, usually I’d make my modifications within Adobe Illustrator but in this case, the number of modifications would be too high and I really need the precision I get by testing a model digitally in my software before cutting and building it. There were SO MANY changes required during this file conversion process so I hope that you enjoy the ride – the only unknown is how well the model will be indexed once all the files are ready to be cut. Will be fun over the following week!