A while back I looked at lubricants for the home shop, with an eye to the physics and chemistry behind lubrication. Talking about how to keep parts moving got me thinking about the other side of the equation – what’s the science behind sticking stuff together? Home shops have a lot of applications for adhesives, so it probably pays to know how they work so you can choose the right glue for the job. We’ll also take a look at a couple of broad classes of adhesives that are handy to have around the home shop. Continue reading “Glues You Can Use: Adhesives For The Home Shop”
[Jia Wu, Mary Sek, and Jeff Maeshiro], students at the California College of the Arts (CCA) in San Francisco, took on the task of developing a walking 3D printer. The result is Geoweaver, a hexapod robot with a glue gun extruder system. Hackaday has seen walking CNC machines before, but not a 3D printer. Geoweaver uses two servos on each of its six legs to traverse the land. The team was able to program several gaits into the robot, allowing it to traverse uneven terrain. Walking is hard enough on its own, but Geoweaver also uses a glue gun based extruder to make 3D prints. The extruder head uses two servos to swing in a hemispherical arc. The arc is mapped in software to a flat
plain plane, allowing the robot to drop a dollop of glue exactly where it is programmed to. Geoweaver doesn’t include much in the way of on board processing – an Arduino Uno is used to drive the 15 servos. Those servos coupled with a glue gun style heater pull quite a bit of power, which has earned Geoweaver nicknames such as Servo Killer, Eater of Shields, Melter of Wires, and Destroyer of Regulators.
Geoweaver’s prints may not be much to look at yet, however the important thing to remember is that one of the future visions for this robot is to print on a planetary scale. Geoweaver currently uses reacTIVision to provide computer control via an “eye in the sky”. ReacTIVision tracks a fiducial marker on the robot, and applies it to a topographical map of the terrain. This allows Geoweaver to change its height and print parameters depending on the flatness of the ground it is printing on. On a scaled up Geoweaver, reacTIVision would be replaced by GPS or a similar satellite based navigation system. Most of the software used in Geoweaver is opensource, including Grasshopper and Firefly, written by the team’s professor, [Jason Kelly Johnson]. The exception is Rhino 5. We would love to see an option for a free or open source alternative to laying out ~$1000 USD in software for our own Geoweaver.