Sunday, March 30, 2014

Drum Plant Part 1: Concept to Casting

The concept for the percussion part of things is pretty much an alien plant that plays itself. It has five pods as the "drums" that its stems will beat. I plan on rigging up LEDs to make each pod glow whenever they are struck. We'll see how that works out. Here's my initial drawing:



Using Super Sculpey Firm clay, I sculpted a single pod and stem that will be duplicated in the casting process:




After smoothing out some of the features, it was time to make molds of both the pod and the stem. I poured an RTV urethane rubber over the clay sculpts in two parts to create the molds.





After the molds had cured it took me a couple of months to get to casting the pieces. I'm a slacker. Sue me. I used an RTV tin-cure silicone that I had on hand to cast the first pod, but realized it wasn't going to work because it ended up being too stiff and opaque. I needed the pods to be softer so I could animate a "squash" when they were hit. Also, I wanted them to have some transparency so that I could light them from the inside to get the glow effect that I mentioned earlier. A bit of research later, I ended up getting some Dragon Skin platinum-cure silicone from Smooth-On. It had the softness and transparency I was after and I found it much easier to work with. Really cool stuff and cures in a quarter of the time. Blue pigment was added to get the base color that I wanted.






To cast the stems, I used the opaque tin-cure silicone since there will be aluminum armature wires down the middle of them that I don't want to be visible. Part B of the silicone mix is already blue so I didn't give it any pigment.


Here's all five of the pods and three stems. I was planning on having five stems, but it's getting a little crowded in the space and animating is gonna be tricky enough as it is. I may add a fourth or fifth since I'm into the challenge, but I'm definitely no Harryhausen.



That's it for now. Part 2 will be all about painting these bad boys.