When I lent my services to a collegue who was working on a film about 12 years ago, I was introduced to the world of cnc. I remember watching this huge machining centre milling out a slab of mdf and turning it into a fantastic set of gears. I knew that it would have taken me hours to achieve the same thing with traditional power tools. I decided then that I would invest in a cnc router for my own business Oxenham Design. At that time I could turn on a computer, but even to check email seemed like a crazy set of operations. I persevered and learned every piece of relevant software I could get my hands on. I am now fortunate enough to be using Vectric's ASPIRE software, and Techno cnc routers, which has helped us to create some amazing projects, both in part, or in full. I thought that this blog would be a great place to share "behind the scenes" adventures with the software, materials and equipment we use, as well as the projects we build.

Monday, 21 March 2011

Mine! Mine!

Just before the Yeti build, I wanted to make a cartoon character. We are now starting to get calls to make life size video game characters, and people are wanting to see real world examples of our work on these types of things. I decided that I would start to make more samples for around the shop, instead of only having what was left over, or returned after a shoot.  I have to say, making cartoon characters real is something that I love. I guess I like the distorted proportions and the fun that they convey. I thought I would post about the process that we went through bringing this guy to life. I started by finding some pretty good reference images on line. I happened to find one of a perfect side view. This always makes it easier to model from. I spent about an hour in our 3d modelling program drawing the various pieces. You'll notice that I left the legs off. This was because we would be using 1/4-20 threaded rods for the leg supports. We would then cover the rods with epoxy putty to blend the legs to the feet.
Next I separated the parts from the model so I could export them individually.
I then imported the parts into Aspire for machining. Because the beaks are symmetrical, I centered them vertically on the zero plane. I was then able to mirror them, which was faster then re-importing the model and flipping it. The feet were relatively flat on the bottom, so I could just slam them down to the zero plane.

I ran a roughing pass on these parts with a 1/4" endmill because I am going to cut them from rigid PVC plastic for the strength. This plastic is pretty hard and it would be faster than nibbling away slowly with just a finishing pass. The roughing pass was offset from the model by .040, so there would be enough material left for the finishing pass. The finish pass was done with a 1/4" ballnose cutter. I was very happy with the results so there was no need to run a smaller cutter.

The body was imported and centered on the zero plane as well.  Aspire has some pretty powerful sculpting tools available in it. I used the smudge sculpting tool to better define the creases on the wings and applied an overall smoothing filter to remove the small triangulated facets that occur when exporting in the STL format. Again I just mirrored the body over because both halves are symmetrical. As I needed them to line up perfectly, this way always works for me. The last step was to machine these on our router out of HDU sign foam. This stuff is great. If you ever get a chance to use, do it. It's dense and carves like butter! We glued the two halves together with urethane glue, using super glue to tack the halves so they didn't push apart when the glue expands. A couple of black cabochons for eyes and some paint and he's done!  I love this guy! I think I'll perch her on a shelf and spill some white paint on the floor under her.


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