Machine for Preserving the Wind show video.

Here is a video showing my latest installation work, Machine for Preserving the Wind. Its up till June 30th, 2011 atTruck Gallery in Calgary, Alberta, Canada.

There is also a review of the show up here at FFWD Weekly.

Oh, and Adam Savage tweeted a link to my sculpture, my inner geek is unspeakably happy.



Each of the 40 poles that make up the piece are mounted on a string pivot, allowing them to sway freely. They have a cast concrete counterweight at the bottom that balances the wooden pole so they can sway with the slightest movement. These are then connected with a series of strings that allows them to be pulled back, and released to sway freely on their own. In this way the poles are indirectly coupled to the drive mechanism, they can be pulled back, but then they are free to sway and swing on their own, resulting a much more organic and random movement than if they were directly coupled.

To drive this mechanism the poles are connected to a pair of large wooden cams. A cam is basically a wheel with an irregular shape that causes a follower on the wheel to move back and forth in a fashion reflecting these bumps. In this case each bump outward corresponds to a gust of wind, and pulls the poles backward. The two wheels turn at slightly different speeds, and the output of each is mixed and averaged, resulting in a program that takes over 14 minutes to repeat.

The cam wheels themselves are driven by a multi stage reduction drive. An electric motor, of the type usually used in a household furnace, is hooked up to a worm drive speed reducer, and then to a two stage chain drive, this setup brings the speed of the motor down from 1725rpm at the input to half of an rpm at the output, a reduction of over 3000:1, this process increases the torque from half a foot pound, to over 400 foot pounds after friction losses. This was fun to design.

Wind Poles - North Glenmore Park

Here's a small video showing those wind poles in action at North Glenmore Park. They move remarkably easily once you get the counterweight mass balanced properly.




Now I just need to make a system of ropes and cams to replicate that movement indoors.

Wind Field prototype and production.

Started working on a new large sculpture, or more accurately a large series of small ones. Basically a set of wind feelers. They consist of a 6' wooden rod that is attached via a pivot to a base. They are held upright by a molded concrete counterweight. The tricky part is that I want to build at least 50 of them.

Scroll to the bottom of this post for a video of it blowing in the wind. 

This is the plasticine sculpt for the counterweight. I calculated the rough volume and dimensions in Rhino 3D, it had to be fairly accurate as the volume will affect the final weight and thus the performance of the sculpture.

The plasticine was built around a wooden core, once the sculpt was done this was removed leaving a hole. In this way I can avoid drilling the concrete after its cast.

To make my production casts I started by making a mold box out of 1/4" plywood, the tapered shape was used to reduce the amount of casting rubber needed for my mold.

I then installed nails in my carefully smoothed model, and suspended it a half inch above the bottom of the mold.The balls form registration pins for the two halves. Once the first half was poured, the nails were removed, the holes filled, and the upper half was poured in.

This is the finished mold made from poured urethane casting rubber. The core in the center has a removable steel rod to keep it aligned.

The finished counterweight. I found out that if I use Quickset concrete I can demold the object in about an hour and half. Once pulled out of the mold I let it set up overnight in a water bucket.

Lots more finished counterweights.

Detail of the sculpture base, The arm assembly pivots off of a piece of string.

Lots of bases, I have made a series of jigs to simplify the construction, there are about 20 of them here, only another 30 to go. 

For extra credit I designed the bases so the legs can pivot inward and essentially flat pack.