Monday, October 11, 2010

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. 

1 comment:

corgimas said...

Very very cool! I cannot wait to see a bunch of them together!
Is there anything on the top end of the bar? or just plain rod???

You should make a point to bring them to a local kite festival to show them off! (contact me to help find one near you!)

Good winds
rob