Skycam assembly gallery and robot debugging
I sold a record number of Drawbots today. Awesome possum! To celebrate, here’s a little bit more about the Skycam I’m going to be bringing to the Vancouver 2012 New Forms Festival, September 13-16. The Drawbot will also be there.
I assembled the Skycam a few days ago. It’s two Drawbots put together with a bit of modified software on top. I assumed I would set up four steppers around a clock face. Each stepper would be at 1:30, 4:30, 7:30, and 10:30. An X+ movement should be towards 3:00 (Berlin), a +Y towards 12:00, and a +Z towards the ceiling. Sounds do-able, but it’s a whole new world of problem solving.
I knew from the start the steppers would be mounted backwards or something. I wrote some code to “jog” just one motor so I can identify which is which and then switch their positions in software. Each motor gets assigned an XYZ coordinate. When my Java program says “Go to XYZ” the Drawbots can figure out the rest on their own.
I also knew that I had to wait for a movement to complete before starting another or accuracy would suffer. That was challenging, and the first time I wrote Listener pattern in Java. Thank you to everyone in freenode#java for their help!
Re-centering a four-string device is a lot harder than a two-string device. I put the origin in the middle of the floor. I still have to manually turn the bobbins which is my least favorite part.
I broke the strings three times already. Lesson learned: run the Skycam with the emergency stop in my lap. Also, disconnect three of the four strings when I’m done with the robot for the day so people can’t get snagged on it by mistake.
So how’s the actual movement, when everything else is said and done? Well…so far the results I get are really confusing. They have to be seen to be described. Anyone interested in a video? Comment now or forever hold your peace.
For a complete description of the build process, read the descriptions and titles of each picture in the gallery. I make no apologies: I have Burning Man on the brain.
If you’d like to build one of these Skycams, let me know. I can package up all the parts if you can get the 2x4s and the drywall/wood screws.