A SCARA Ball Bearing Placement Robot
This SCARA robotic arm uses three servos under Arduino control to place ball bearings.
Selective Compliance Assembly Robot Arms, or SCARAs, are widely used in manufacturing in order to pick parts off of a plane and place them in the proper orientation elsewhere. This type of robot can achieve impressive speeds, and provide relatively low maintenance operation. While industrial models can cost thousands or tens of thousands of dollars, this little SCARA demonstrator can be built using an Arduino board and hobby servos, plus several 3D-printed parts.
As seen in the first video below, the device twists its ‘elbow’ and ‘shoulder’ joint to change its X/Y position, then uses a micro-servo in order to actually drop a .45mm bearing. Control is via an Arduino Mega clone, though any board capable of controlling three servos at the same time could seemingly be used. Code and print files for the demo are available in the project's write-up, and you could expand on it to make something even better.
One interesting bit about the design is that the shoulder and elbow joints are kept rigid in the vertical orientation by the same bearings that it’s designed to dispense. Also, heat-set threaded inserts are used along with screws to secure the parts together, offering an attractive robot base that could be used for many different projects.
