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.

Thursday, 15 December 2011

Oh Those Jagged Edges!!!

This week has been a flury of computer modelling for us. We have been cramming to get out 5 relief models that other sign shops have contracted us to build. Sometimes this is a nice change from getting dirty! Although, after awhile I start to crave Techno cnc dust.
One of the jobs I haven't had time to get to until last night was a sign for a Mustang Shelby shop. It's a pretty straight forward design, but still kinda cool. I decided to use the filler cap from the back of the car as a start.
I drew up some vectors in Aspire, laying out the various possibilities to this straight forward job. I also modeled the cap portion in Hexagon, as I was already modelling another job in there anyway.
The center of the cap will get the snake and "Shelby" text. There is no faster way than Aspire for that!
I brought the cap model in and sized it to the vectors. I also added a blotchy style texture I created earlier this year. It didn't take long before I had a relief ready to machine on our Techno cnc.
I couldn't resist using our cartoon font again. It's so bold and fun!
One of the things I see a lot on the Vectric forum are people asking about jagged vertical edges on parts of their machined models. This is one of the common things that are present in all software like Aspire, from $500 to $10,000, it's the same. This is because Aspire is basically pixel based modeling. This means it converts a greyscale image into a 3-dimensional model. If you take a low resolution image, and zoom way in, you'll see what I mean. As the pixels reach the vertical edges, they get jaggedy. Some of this can be eliminated by modeling at very high resolutions, but stuff like raised text will always suffer to some degree. However, all is not lost to the elbow and sandpaper! One of the tricks I have learned over the years is to fix this with smarter toolpathing. As you'll see on the text of the Shelby sign, there is the text itself, the offset text shelf it sits on, and the texture plate. When I started, I would have baked that all together into one giant lump.
I learned that the best way is to keep them all separate.

Tomorrow, I will dive into that deeper, as well as post some of the sign in progress.

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