Introduction: Stratum Networks Delta Robot
Stratum Networks is a computer aided kinematically driven robot that can be used for rapid prototyping and fabrication. Its most basic logic and methodology are applicable to scale at an architectural level. It is a tool for digital and physically simulated speculation and has been designed for re-adaptaion and indeterminacy.
Delta Robots are a type of Parallel robot. Their use has been standardized in both the automotive industry and in packaging lines. Delta robots have a high level of precision, and a speed that is ideal for a wide range of uses. The triangulation of the three delta arms produce kinematic chains that supply three degrees of freedom, x,y and z. The delta Robot uses parallelograms that restrict the movement of the toolhead. The positioning of all mechanical actuations (motors) are located at the base of the robot which allows for the robot positioning arms to have a small inertia. Delta robots can be made from a relatively small amount of parts and mechanical connections, which makes them ideal for many applications. They are easy to fabricate and have very little weight. With very little math and proportional relationships, delta robots can be programed for many purposes.
Max Sanchez and Taylor Fulton are architecture students at California College of the Arts. This project was based in a studio course called Creative Architecture Machines taught by Jason Kelly Johnson and Michael Shiloh.
Step 1: Structure Parts
- 1/4" Birch Plywood for the outside structure of the robot
- 1/4" & 1/2" Acrylic for the arms and the extruder head
- 1/8" Machine Screws to hold all of the 3D printed PLA parts together
- 1/8" Acrylic rods to hold the arms and extruder head together
Each individual part should be laid out in AutoCad or Rhino. Make a separate file for all the different types of material and material thickness used. Then laser cut the materials.
The machine screws work better for holding materials like PLA and Wood together, and the Acrylic rods work well for assembling just the Acrylic pieces together.
Step 2: Electronics
- 3 NEMA 17 stepper motors
- Sparkfun Quadstepper Motor Board
- 3 Limit Switches
- Electronic wire
- Arduino Uno
- Prototyping shield
- 12v 5 amp power supply
- USB connector to Arduino
The Three stepper motors should be assigned to 3 separate channels on the Quadstepper Motor Driver board. Colors of wires may vary from different manufactures. All motors should be labeled and paired with a limit switch that will be used for homing the robot. One limit switch is then installed at the top of each vertical axis, and one stepper motor at the base in a motor holder. Be careful mark and label everything for easy debugging when connecting to your computer.
In our research we found the SPARKFUN Quadstepper Motor Driver schematics to be useful when wiring the stepper motors to move at a specific incremental speed. ( 1/8step, 1/4step, 1/2step....ect.) ours were wired for 1/4.
One resistor is located in each limit switch circuit.
Channel One: Pin 3, Pin 4
Limit Switch One: Pin 11
Channel Two: Pin 5, Pin 6
Limit Switch Two: Pin 12
Channel Three: Pin 7, Pin 8
Limit Switch Three: Pin 13
Step 3: Extruder
- Regulator with Blow off
- ON/OFF Valve
- Connector to compressor
- 2 way barb
- (see image for assembly)
Two Potential Types:
3D printed holder
3D printed cap
luer lock tips
2 bolts / wing-nuts
Poly-carbonate 3 in tube
1 3in to 3 in threaded fitting ABS
1 3 in to 2 in reduction fitting (threaded) ABS
2 2 in to 11/2 (threaded) ABS
2 galvanized reductions
2 compressor barbed fittings
Step 4: Assembly
Nuts and Bolts
Drill and Drill Bits
3 Timing Belts 2mm pitch
3 Plastic Pulley's 20 teeth
6 Stainless Steel Rods 3' lengths
6 Linear Ball Bearings
Once all the parts are laser cut and 3D printed, the assembly process should go pretty smoothly.
- Glue the stepper motor holders, and rod holders on, and then screw the stepper motors in first before attaching the two wood beds together.
- Put the metal rods in and slide the ball bearings on before attaching the top piece.
- Attach 3D print part onto the ball bearings
- Attach timming belts through 3D print part and on the top and bottom pulleys.
- Screw in 3D print parts for vertical rotation, and horizontal rotation.
- Screw in arms and top plate
Step 5: Softwear
- Arduino is interfaced with a modified version of the Quadstepper Firmata written by Jason K. Johnson and Andy Paine.
- All Controlling of the Delta Robot is done in Firefly, a plugin for Grasshopper in Rhino.
- Attached are two Grasshopper files that are the necessary files for basic operation and control of the Stratum Networks Delta Robot. One file brings the machine to it's homing position while the other controls the path it takes to make the artifact.
- See SPARKFUN for Quadstepper Motor Driver schematics
Step 6: Clay
- CUSTER FELDSPAR
- SILICA #5 325mesh
- KENTUCKY BALL CLAY
- DARVAN: Used as a deflocculant. A few drops of the fluid will make the clay compound more like a slip.
- GROG: reduces shrinkage
These are the five different types of clay that we mixed together, + a slip that increases the fluidity of the compound. We bought them as a powder and mixed the right amount of each one to make the clay print at a state that could be extruded upward without it falling down.