Archive for December, 2010

Harmonograph for the 2010 East Austin Studio Tour

Thanks to everyone who dropped by at our studio for the East Austin Studio Tour last month.  We had a nice stream of visitors at our gallery space where Sally and I had some of our art work displayed.  We sold a few pieces as well.

At the last minute I decided to build a harmonograph in the shop since I didn’t have another project ready to show.  After a few years of EAST,  people come by and expect to see something interesting.  On the Thursday before the first weekend, I started building a rather complex harmonograph.  I had an idea for a linkage scheme to combine the motions from two pairs of pendulums.  The whole thing would fit nicely on my big worktable.

I did not have enough time to build all the degrees of freedom into the linkage so I hacked away and ended up with a complex gadget that had too much friction and didn’t work!  On Saturday morning I started to quickly  simplify the thing.

My friend John drove out from Houston for the weekend.  He arrived at about 10:30 am and joined me in re-working the harmonograph into something that worked fairly well.  Lots of people came through and spent some time watching the drawings form.  It was hypnotizing.  Some folks hung out for over an hour and took turns creating patterns.  We added a third pendulum which moved the paper in one axis and that’s the way it stayed through EAST.  After the second weekend of EAST I modified the harmonograph again and added a fourth pendulum so the paper was driven by two pendulums and the pen by two more.  This is what you can see in the YouTube video.   I hope to design a nice portable harmonograph so I can have one to demonstrate at schools and such.  A few people asked if I would build them one.  I’ll ponder that idea.

Here are a few results from the harmonograph:

( Click on the images to see them big.)