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.

Sunday 2 September 2012

just another week on the town.

Jody was pretty much responsible for the fabrication of the 6 pc dock set. These were all made from 1/4" pvc. They're basically just trays. She made them just over 2" deep, so we could hide a piece of styrofoam up inside them. These sections will daisy chain together, so they can move up and down with the waves that "Bob" the boat will be making.
She cut the grooves for dock boards on our small table saw with a .030" blade in it. The cuts don't go right through, as we need the strength of the full piece. These floating docks will actually have all the cars on them, so they need to be durable, and bouyant. The hinges were made from 3/4" pvc. I drew the file up in Aspire, and the Techno cnc made short work of it!

We primed them with a rubberized spray. This lets the acrylic paint stick pretty well to the pvc, plus it gives a nice texture to the surface.
Once the final paint dried, Jody screwed all the hinges on and got the styrofoam up inside them.
They looked fantastic when they were done!
While the dock was being built, I was working on the 2 dump truck boxes for the character "Dug".
This was pretty straight forward as well. I drew them up quickly in Corel, and toolpathed them in Aspire. The sides were made from 1/8" styrene. I built each side from 3 pcs. One piece had the rabbet for the 1/8" acrylic bed, the second one was the basic shape, and the 3rd piece has the ribbed detail on it.
I wanted the bed of the dump truck 1 piece. This would be the strongest option with the least amount of weight. There are actually 2 dump trucks. One has a servo motor for fast lifting up and down, and the 2nd one has a worm drive for heavy loads. Filled with dirt, it will be fairly heavy, so I wanted our stuff to add as little as possible to it. The bending of the 1/8" acrylic was pretty smooth sailing. I cut a full size template for it from vinyl and stuck it to a board. I used our heater strip to make the bends.
Once the pieces were all made, the whole thing just snapped together. I solvent welded the styrene sides to the acrylic bed and clamped them for about an hour. Red was the only colour we had, so red it was!
The construction colour we chose is pretty opaque, so I didn't worry to much about the white and red being so drastic.
A few coats of paint later, and the dump box was done. One more thing off the list.
The head for Dug was next on the list. This was all 1/8" styrene as well. We had the room inside to add 1/4"X1/4" strips for strength. Every piece was cut on our Techno cnc, this allowed for very easy assembly.
John, who is working with us on this, is a great model maker, and has great knowledge of Illustrator, drew up Dug in Illustrator. The most complicated part of his head is the tapered, curved eyebrows.

 I took the eyebrow arch, as well as the profile length he drew into Hexagon, and used the curves to quickly build a model we could use as a vac mold. I exported this out to Aspire for quick toolpathing. Once into Aspire, I was able to get an accurate base profile vector that I could use to cut the holes in the roof of the truck for the eyeball clearances. We standardized all the eye shapes and brows across all the construction vehicles. I cut the form from HDU. As we were pulling 1/6" styrene over it, I didn't have to sand the form at all, as the small machine marks wouldn't imprint through the 1/16" plastic.

All of the eyes get split tubing around them, kind of like a cartoon drawing. I decided to pipe one eye with it, just to see how it was going to look.

Lookin' good Dug, lookin good!
8)
JO


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