Everyone needs a hobby; mine happens to be making violins and violas. I'm currently making a copy of a Brothers Amati Viola dating from around 1620, and I want my reproduction to be as accurate as possible.
Making the templates for the front and back arching is a slow and tedious task, so using my background in computer programming and 3D modelling I thought it would be an interesting '10 minute job' to 3D print my templates from the contours on the paper plans.
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Being a programmer, I decided to photograph the plans then write some software to generate lots of 2D points for each contour in the image. This '10 minute' job ended up taking several evenings. As always, the devil is in the detail! It seems that an iPad photograph is not exactly to scale, even when the pixels are transformed from perspective/camera points to 3D orthographic/world coordinates. I finally managed thanks to a kind colleague scanning in my plans accurately. |
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| The next '10 minute job' was to pass the 2D points to a solid modeller, and instruct it to offset and extrude my contours into 3D shapes to output as STL files. Because I had so many 2D points to work with, I decided to use the solid modeller API to manipulate everything. Again, this small task stretched out a fair bit, what with the infamous SolidWorks 'rebuild errors', and the 'snap to grid' feature moving all my carefully created 2D points around. |  |
| I eventually got my set of STL files out of SolidWorks, ready to email off to a printing bureau. I wanted to check they were properly healed, or else they wouldn't be printable. However this time I knew I really did have a '10 minute job', as the company I work for produce software called Polygonica, which does exactly this. Of my ten STL files, Polygonica identified in seconds that one file had been badly created by SolidWorks, with some triangles in the wrong place, cutting into other triangles, and some facing the wrong way. Just one button press and 20 seconds later Polygonica had healed the faulty geometry for me. At last; a 10 minute job that really was just that. |  |
| Finally I had to look round for a printing bureau, as I've never printed anything before. A bit of web searching pointed me to lots of sites that asked me to upload my file, and then just told me a salesperson would phone me with a quote tomorrow. This was fustrating as I know our Polygonica software could quite happily just sit on these web sites and automatically calculate this immediately. However I eventually managed to find http://www.uk-3d.com/, whose website managed to give me an immediate quote based on volume of my STL files. As it turns out, one of my templates was bigger than the maximum printing size, but a quick phone call with David at UK 3D sorted the issue perfectly. I could not recommend these people highly enough for their professional, flexible, helpful advice, and I'm stunned by the accuracy of the templates I got back through the post. I can actually feel a crease in the original paper plans that has made its way through to the plastic templates! |  |
| So I've finally got my 3D templates, and am now happy to get back to carving wood again, knowing that this next bit definitely won't be a 10 minute job. - John Kite, Senior Technical Consultant, MachineWorks Ltd. |
