Kinetic art: autonomous spherical robots exhibiting complex motion

As of Saturday night, the pieces for all 6 orbs have been cut! Rich Humphrey, Jon Foote, Rick Lellinger, Lisa Schile, and myself worked two marathon sessions totalling more than 20 hours to keep the Omax Model 55100 abrasive waterjet machine running. The result is more than 500 cut ribs, giving us a few to spare beyond the 480 necessary to fabricate 6 orbs.

From Mike:

Just a brief note to let you all know that Lisa, Steve Monahan, and I
finished welding the aluminum orb last night and brought it to the Box
Shop for testing. There, Erik, Lee, Jon and I got it running and put
it through it’s paces. I’m pleased to report the test was a success!
I am confident that the current design with 1/8″ 5052-H32 aluminum is
structurally sound and rolls acceptably smoothly.

Special thanks are due to Jack Schroll, Steve Monahan, and Germ
Travis, who went out of their way to help us out in our hour of need!

Otherwise, a couple modifications were made to try to improve steering
performance, based on the feedback from many people to make it the orb
easier to roll straight and avoid a high point at the equator.

One was to cut into the equator rings (annuli) to keep them from
sticking out further than the ribs. I think this is successful, and
its my intention to move forward with this design feature.

The other was to make a elliptical cutout on all the elements near the
equator so that there is a kind of flat spot in the middle to provide
a slight centering force. The consensus last night was that at 0.2
inches of the radius, this was too extreme a cut. This self centering
tendency resulted in a significant trade off with turning ability,
logically enough. My feeling is to move forward with a more subtle
cut; I will be experimenting with the geometry to see if there is any
way to make sense of deciding the optimal balance of self-centering
and steering capability.

-mike

And a little supplement from Lee

We put in a late night Wednesday night…

- The orbs look great :-)… like something made by NASA or a benevolent alien race come to destr^H^H^H^H greet us.  Clear anodizing at the Tech Shop could keep them looking like that for a long time.
- they didn’t bend or buckle or nuffum :-) :-)
- they were designed to be a little flat at the equator to help stabilize them…. maybe they were too flat… we’re still thinking on that
- it’s pretty hard drive around smoothly. It sometimes rocks around uncontrollably…. solutions to that are forthcoming…
- some PID feedback loops have to be tweaked a little
- maybe the length of the steering motor throw has to be increased
- we didn’t try it on soft ground. Only in the shop.

That’s the most of it. I’m off to install the TIG welder :-)

Our latest toy arrive yesterday. It’s a Lincoln Electric Precision TIG 225. This will help us get the orbs together and enrich the Box Shop for years to come. After getting it installed in the Box Shop, Michael and I got some play-time (IE practice time) and all I have to say is “Weeeeee!”

Behold…

Here it is test-fit together, after hours of grinding by Ray, James, and Michael.

Tomorrow, with luck, we weld.

Ray rocks. He’s come up with some plans for the mothership.

(local copy)

We came, we rolled (local copy). We blew a fuse, replaced it. We lost a chain. We fixed it. We encountered significant deviations from the spherical, when we jumped the track at the Power Tool Drag Races . (We lost, but to a puny human on a scooter.) Watch out, humans, when we get our new 0.125″ aluminum shell.

We also met very very many cool people, far too many to list. Thanks to everyone who came out to help!

We’re going to make a bunch of half-scale SWARM shells out of wood, to sell as art lamps for a fundraiser.  Here we are Laser Cutting the first one at the TechShop.

All us SWARMies are happy to announce that we have made our wiki and our source code available to the world! We are making this available in the spirit of progress and sharing. Go ahead, take a look under the hood!

We’ve licensed the entire project under the Creative Commons Attribution-Noncommercial-Share Alike 3.0” license. Check our license page for more information.

The source code is the software that controls the orbs, written in Python, C, Java, bailing wire and what not. If you’d like to work on the code (or any aspect of our project), join our mailing list and introduce yourself. We welcome new members.

The wiki is a discussion space, information and documentation repository for the project.

Note that we had initially released the project under the Creative Commons Attribution 3.0 license but changed that shortly after.

We are all very happy to say that we have made the entire SWARM project open source! We have licensed everything under the “Attribution-Noncommercial-Share Alike 3.0” license.

In brief, this means you can use our research, implementations, software, blueprints, ideas, technology, firmware, board designs… anything you want… as long as you give us a shout-out and aren’t trying to make money off us.

If yours is a commercial work and you want to use our stuff, we urge you to contact us. If your project is interesting, we’re quite likely to grant you a full license to our work.

Imagine making your own SWARMania, standing on the shoulders of geeks!

Find out more about the particulars of licensing on our wiki.

Note that we had initially released the project under the Creative Commons Attribution 3.0 license but changed that shortly after.

Too many posts without a picture. Here’s our logo: share & enjoy!

So Mike spent the weekend upgrading the shell and last night we drove it around some more. It’s getting there! Much smoother rolling and more robust. It was good to see how well it would stop and start. The drivetrain is working really well, though the steering has some issues. We took the Orb to the parking lot: it has no problem rolling up minor hills, but steering is tricky, and we also took it to the park so it could play on grass for the first time in its young life.

Still some issues: we found that the steering motor gearhead was jumping teeth, so we’ll need one with metal gears instead of plastic. Once we get that going then we can start to tune the steering motor control. Lots more things to do: mount the prototype circuit boards, lots of software development. Anyone interested, please get in touch: info@orbswarm.com

We also hung a door on our little elevated space at the Box Shop. Now I’m afraid I can’t call it anything but the “SWARM Dorm.”