The builders and bots were there
We filled the room and made things go boom
you really shoulda been there.
The above essay should remove any doubts anyone has as to my abilities as a poet. Still, it was a fun event. One group had a B-25 front fuselage, made by their students complete with a honkin big sound system that simulated the sound of the engines and the firing of the machine guns. The rest of us could have done with less of the sound effects.
St Vrain Metal Works makes fixtures from plumbing pipe and polished brass, most come with a dimmer disguised as a water valve. This one featured an artificial horizon and propeller.
Lots of 3-D printers making various stuff:
Jeffco Open School, where I sometimes help had several of their robots including Chad Pi
There were autonomous vehicle races outdoors which I managed to miss while I was manning the table inside.
These things are fun, even more so if you bring the kids. I brought the golf caddy trike (scroll down, it's on here somewhere.) and let the kids take it for a spin. It's entertaining to watch a kid get on the thing, get focused on the throttle knob, and drive into a wall after forgetting what I told them about how to stop. First turn the throttle OFF!, then use the front brake lever. The rear brake lever DOES NOT WORK! In one ear and out the other.