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.

Friday, 23 May 2014

Water Slides aint a BIG deal!

The cool thing about our work is I NEVER know what will come next! Our latest job, which I have been a slave to the computer for at least a week, is a water slide! However, it will only be 1:6 scale.
It's for a commercial shoot the 3rd week of June. This will be a joint venture between full size waterslide sections, with live actors eventually being composited into our miniature slide.

The complicated part is making it look good. One would say "Why not build it like it is in real life?"
Fair enough, but in real life, a water slide is generally made from 2 half tubes that bolt to the next section. The downward angle is made by offsetting the joint between the two sections.
In real life, the tubes are covered, probably so people don't go flying out on the hair pin turns! Our slide needs to be open on the top to see the spokeswoman sliding down it. If I was to remove the top half of the above tubes, the edges would become stair-stepped (shown in red). WAAAAY to ugly to make it like that!

This means designing flanged tube sections, without any stair-stepping, that will align perfectly with whatever section they will join on to. And to be able to flip them for small covered sections, and still line up perfectly. All while maintaining a consistent downward spiral. And that's only the first part!
The second part is building a slide, that meets the mechanical requirement of support structures, without having the supports block any section of the tubing run, all while looking great as a whole. And it all has to work with the other elements that are being made at another shop!

This was a total PITA to design. The final agreed upon version was revision #27. That's a lot of revising! As a matter of fact, it was over 40 hours of revising!

As far as I know, this is the final scale version. The other problem I encountered about 26 times, was with every small change to the run, the whole thing gets changed down the line, forcing a complete re-build to satisfy everyone.

As the Art director uses Sketchup to design in 3D, I exported my final Hexagon model to Sketchup, allowing him to add it to the set model he was building for the rest of the commercial. The Sketchup Sally girl is just there for a scale reference.

I just have to prep my tube sections for import into Aspire, and I'm ready to machine. We will be vac-forming these section from .060"pet-g. I'm going to try hard-coated HDU for these molds, we'll see, but they should be good for a few pulls at least!