My geeky colleague Jane Irwin sent me and the girls a gift – a baby rhinoceros!
Technically, this is a model of the "Animaris Rhinoceros Parvus", one of Theo Jansen’s kinetic sculptures. If you haven’t seen Jansen’s work on the move, you should really check out his site: http://www.strandbeest.com/.
On Saturday, Katherine, Lucy, and I laid out the parts
And got to work.
Up to now, science or engineering projects like this have been Katherine-and-I, or Lucy-and-I. This time the three of us wanted to work on it at the same time. We had a few false starts trying to get organized, but eventually we settled into a groove. Lucy and I took turns popping pieces off and filing down the burrs.
And I got Katherine going on the assembly once we had the initial few parts ready
Much of our initial time was spent assembling the rhino’s 12 legs:
I put the first pair together with Katherine and Lucy’s help. The pieces just snap together, but we had to maneuver four of them at the same time, so any one person quickly ran out of hands.
We learned a few tricks with that first pair of legs, so Katherine was able to assemble the next pair by herself while Lucy and I finished up separating the pieces. After about an hour, we had half of the rhino assembled. The girls took a break while I started work on the other half. The next pairs of legs went together even faster, so the second half only took about 20 minutes – give or take the additional 20 minutes of tearing it all down and rebuilding it because we used the wrong control arms on the first set of legs.
After 90 minutes, we had the basic rhino assembled.
The last couple of steps were the gearing, which I added, and the sirocco fan that would drive it, which Katherine assembled.
Once it was fully assembled, we took it out for a test walk, but there was a noticeable clicking that we thought probably wasn’t right. We found some of the upper control arms that connected the drive shaft to the legs needed to be adjusted to make the rhino walk more smoothly.
For each leg, there was an upper control arm and a lower control arm. Two pairs of these attach to the same point on the drive shaft. Originally we just alternated them on the shaft, but afterward I realized that they were getting torqued out of alignment, and starting to rub against each other with every revolution. I modified the order that they attached to the drive shaft and it went a long way to smoothing out the action.
We also found that the gear attached to the drive shaft would stop once a revolution, and jam the second gear.
I figured there was due to a burr on the outer rim of the gear, catching every pass, so I took the gears off, and filed down the edges, and reassembled it. That appeared to solve that problem.
We next tried the rhino outside, when there was a good wind. That worked only in spurts, however. The rhino moved slowly but steadily when the wind was blowing, but it wasn’t very constant. In the end, at Jane’s suggestion, we got much better results using a hair dryer.
All in all, this was a very cool project. Thank you Jane!