In our first version, we attempted to prototype our vision of putting multiple modular delta robots in close proximity and seeing what we could achieve using a linear actuator design. This initial design was used as the basis for our RSS paper and is the cheapest version. However, the linear actuators used in this design did not provide any positional feedback, which we fixed by purchasing different linear actuators in the second version.
All of the CAD is located in the Google Drive below. The 3D printed parts are also uploaded in STL formats.
Print the following parts according to the number of modules you would like to have.
Two Modules only
Single Module
Two Modules
Screw the linear actuators together using the Female Threaded Standoff, Top Delta Module Plate, Bottom Delta Module Plate, and Top Edge Pieces. You will need to use around 7 washers with the 3/4" 8-32 Button screw.
Attach the Arduino Mega Holder and the two L298N holders using the 3/4" 8-32 Button Screws and the Nylon Nuts.
Attach the Arduino Mega and two L298N boards using the 4-40 screws and nuts.
Connect the 2 Top Delta Module Plates together with the Top Delta Connector and the Female Threaded Standoffs. Make sure to put around 7 washers with the 3/4" 8-32 Button screw. Also attach 4 linear actuators using the Top Edge Pieces.
Screw the rest of the linear actuators together using the Top Edge Pieces, Bottom Delta Module Plates, and the End-Effector Mount.
Attach the Arduino Mega Holder and the three L298N holders using the 3/4" 8-32 Button Screws and the Nylon Nuts.
Attach the Arduino Mega and three L298N boards using the 4-40 screws and nuts.
Follow the Guide here in order to wire the Linear Actuators to the L298N modules: https://lastminuteengineers.com/l298n-dc-stepper-driver-arduino-tutorial/
Make sure that you connect the ground between the 12V power supply to the ground of the Arduino Mega.
We used ROS and rosserial to communicate with the Arduino Mega. However, in Version 2, we decoupled from rosserial and instead utilized pyserial. We only tested this on Ubuntu 18.04.
Install ROS following instructions here: http://wiki.ros.org/ROS/Installation
Install Arduino IDE following instructions here: https://www.arduino.cc/en/software
Install rosserial following instructions here: http://wiki.ros.org/rosserial
Download our mini-delta-robots-V1 package here: https://github.com/iamlab-cmu/mini-delta-robots-V1
Make sure that all the pins match according to the code. You will also need to compile and source the catkin_ws in order to build the delta_msgs using rosserial. There is a tutorial here: http://wiki.ros.org/rosserial_arduino/Tutorials/Adding%20Custom%20Messages
Compile and upload the code to the Arduino Mega.
Run our example joystick control code using the ROS joy node. We used a wireless PS4 Dualshock controller using Ds4drv.