I love epoxy
For the past few weeks Andy Goralczyk and Eva Franz have been visiting the Blender Institute to work on finishing up their stop-motion/CG short movie Omega. It’s been great to watch their progress on that, and I’m really excited to see the finished product.
I asked for their opinions on the knob-and-nuts joint and some other parts of the animation model I’m working on, and Andy pointed out that when I use the joint for the dog’s shoulders and hips, I will need a way to prevent the knob itself from rotating around its base screw. It was a good point. At first I had thought just screwing it tight would be enough, but on a little more thought I realized this would be a problem during animation.
I think I found the solution. First, I found some small wood disks to bolt the knobs to. Next, I filed several small notches into the base of the knob. I hammered some small nails into the disks to match the notches in the knob and keep the knob from rotating. Then I got the strongest wood-metal epoxy I could find and epoxied the knob to the base, with the bolt running all the way through it, which will be fastened to the body of the robot. Four other bolts will also hold the disk to the body and keep it from rotating.
It’s Andy’s view that once animating starts, everything is more or less guaranteed to fall apart. But these epoxied knob-bases are pretty darn solid. I can’t see these coming loose.
All the same, I’m going to make some extras.