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.

Wednesday, 13 March 2013

My hands are awesome! UPDATE............................

We got to the shop pretty early to cast up the painful mold of my hand we finished yesterday!
The redness on my arm was gone today from the instant hair removal. Gone, but not forgotten.

We did the pour in six stages per hand. There is undercuts everywhere in the mold, and I don't think we would be able to get all the air out of the mold in one shot. We slush cast each pour as we went.
We had zero air bubbles in the final cast. This sometimes can be a surprise, cause you never really know with a mold that has this many air-trapping pockets. The seam up the arm was not really much more than a bit of flashing, the alignment on the rubber was really good.
It wasn't until we had a cast part that I was able to physically see the reason for my painful de-molding experience! It seems the resin was strong enough to pull any of the hairs in the rubber mold right back out, and place them perfectly into the casting. Sorta gross really.
The next step of the build was to "meld" the hand and steering wheel into 1 object, so the hand and car become "one" We used epoxy putty for this step, as the working time is fairly decent, and it's extremely versatile.

Once we were happy with the overall shape of the "meld", I used crumpled plastic wrap to add the fine surface texture of skin. We let this set up for about 4 hours.
Using a Sharpie and a piece of 1/4" masking tape, I was able to lay out all the dimples that are found in the perforated racing leather they wanted. The layout took a very long time! After the layout was complete, we used a small drill bit in a manual drill to dimple the surface. 7 rotations per hole put the depth just right. This took even longer than doing the layout, mixed with the odd hand cramp.
Color aside, it's a bit weird to drill an exact duplicate, including hair, of your own hand.

Once we were done, it got a thorough cleaning with lacquer thinner, and a long bolt inserted into the "away from camera" side. This will let them mount the hands into grip stands on set.
We finished up with a few coats of satin black laquer, and set them aside to dry. Delivery first thing in the AM.

As soon as we drop these bad boys off, we're picking up our rental car, and heading down to New York. It's going to be great to go back to Techno CNC and see everyone. I'm really excited for their cnc sign making demo they're hosting on Friday!
Hopefully we'll see you there!!


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