Constant force springs

There is some confusion about the "special springs" I use in my sculpture. The assumption is that they are a kind of spring motor that drives my sculptures at a constant slow rotational speed. What they actually provide is a constant rotational force or torque, not constant rotational speed. If the spring is not constrained in some way it will unwind very rapidly.

A traditional coiled clock spring gets "tighter" and provides greater torque the more you wind it. A constant force spring provides the same torque or turning force through out its cycle. You can find sources for constant force springs and much more information on their uses by doing a Google search on "constant force spring."

A good way to emulate a constant force spring is to attach a string to a freely rotating spool and hang a weight from the string. Wind the string up onto the spool, the torque or turning resistance you feel is pretty much the same as that from a constant force spring. If you release the spool the weight will drop and the spool will spin rapidly. You need to add a mechanism to control this rapid unwinding. My sculptures are essentially mechanisms to control the rapid unwinding of a spool. The general class of mechanism is called an escapement. Spring and weight driven clocks also use escapement mechanisms.

Clock escapements are designed run for long periods of time at a regular pace. I design my escapements/sculptures to produce visually interesting and sometimes random patterns. The important point to understand is that I don't power my sculptures with an escapement mechanism, my entire sculpture is an escapement mechanism.

Shipping and Journey

It turns out that with just a slight bit of modification to the way Journey is installed I can ship it in a much smaller box than I normally use. This will save a good bit on shipping expenses in today's high cost energy world. The cost of shipping my normal box to Europe has ballooned to something over $500 with added fuel surcharges. Journey, in this new box, will ship for less than $300.

Exploring "bird" motion

A year or so ago I decided it was time to explore "bird" motion a bit more.  The first sculpture was a large piece with a slow, graceful motion. It went through several iterations as I played with the form of the bird carrying wheels but I was pleased with the efficiency of the form of the swooping "legs" or power levers. The only problem with the piece was that it was too large to be an edition sculpture. Sculptures look much smaller on the computer screen when I'm designing! 

I took this design and reduced it by about half. I had to modify the mechanism to make it work correctly but I liked the effect of the reduced size. The motion was quicker and more dynamic and I could pack the sculpture in box that would fit within normal UPS size requirements.

The first sculpture I named Eagle for its soaring motion. The second sculpture became Falcon because it had elements of the soaring motion combined with a quicker darting effect.

At about this same time I started working on another bird sculpture with an entirely new mechanism. The working title for this piece was Sparrow because I thought of it as a smaller piece with a more unpredictable motion. Sparrow ended up being the most challenging of the three designs. I almost gave up on it numerous times. It the end the name Sparrow didn't fit any longer and it became Journey.

Falcon and Journey are both on the web site and in my studio as edition sculptures. Eagle sold before I had a chance to show it on my web site.  Putting up photos is yet another item on my to-do list!

First Post- inside Wood That Works

Thank you Amy and Karen! Here's my first post.

The test production run of the first 2 Journey sculptures is going well. I'm very pleased with the motion and run time. I like this piece a lot!