But if you do take it upon yourself to accept it's challenges, it's rewards are great: it is a six-legged, walking 3D printer. The center mechanism uses two servos to control the pendulum-like extruder head, allowing it to cover a basic XY plane (though curved to the surface of a sphere, see video above), and one servo for the extrusion gear that forces the glue-sticks through the "print head." All of this can be controlled through the software Rhino 5, with the plug-ins Grasshopper and Firefly (developed by our professor Jason).
First, we must mention an Instructable that aided us at the start of our prototyping, the Hot Glue Gun Extruder for Your CNC Machine or 3D Printer project. It gave us a great starting point for our print head and we were grateful for the leg-up. Second, we utilized this tutorial to figure out how to do spirals in Grasshopper, though the spirals we made came out pretty intense.
Third, here is a video of the 62 day development process with different material tests and trial robot versions.
Lastly, this project was devilishly and deviously difficult and would not have been possible without our professor Jason Kelly Johnson's guidance (even writing a custom Arduino-to-Firefly firmata for us to be able to use the servo shield, see Step 8). And of course our other professor Michael Shiloh's sure-handed advice, most especially with the wheeled toes, a pretty nifty bit of mechanical innovation, if we are permitted to say so. Thanks also to Andrew Maxwell-Parish of CCA's Hybrid Lab (and Instructables Artist In Residence ElectricSlim), your help with our projects was matched only by your enthusiasm for all of them. We are grateful to all three of you for your invaluable help.
Anyway, let's get Instructablesing.
Required Items (tools):
- Vertical band saw
- Phillips/flathead screwdriver in multiple sizes
- Power drill and drill bits
- Wire cutters
- Needle nose pliers
- Measuring instruments, ruler or vastly preferably calipers
- Laser cutter
- 3D printer
- 15 high torque servos (complete with the "+" shaped servo horns and servo center screws that should come with the kit
Bolts and locknuts (about 48 of them), or whatever bolts fit through your servo flange holes (the side holes). At least 3/8'' long (enough for the 1/4'' plastic or Al and a locknut to fit on there)
- 1/8” at 24” x 48” sheet of plywood (for legs/center mechanism)
- 1/4” at 24” x 48” sheet of plywood (for body)
- 2 bags of hot glue
- 1/8” at 11” x 17” sheet of acrylic (for extruder)
- 3 bags of 100ct mini zip ties
- Small gauge wire
- 6 rubber sink washers
- Arduino Uno
- Servo shield
- Male headers
- Jumper wires (or single core wire suitable for breadboards)
- Servo extension cables
- Rhino 5
- Grasshopper plugin (for Rhino 5)
- Firefly plugin (for Grasshoppper)