One of the limitations of the traditional Cartesian CNC platform is that the working area is usually smaller than its footprint. SCARA arm is one of the options to solve this problem, such as [How To Mechatronics], With his SCARA laser engraving machine.
This robot arm is modified from the original version we showed a while ago, and it is equipped with a gripper. It mainly uses standard 3D printer components with 3D printed frame parts. The size of the arm length can be folded on the base, and only takes up little horizontal space on the desktop when not in use. It can work in a semicircular area around itself, and if proper positioning and homing methods are adopted, it can move around and engrave a large area piece by piece.
One of the challenges of the SCARA arm is rigidity. When the cantilever is extended, it tends to lean under its weight.exist [How To Mechatronics]In this case, it appeared as a slanted engraving, which he managed to mitigate to some extent in the Marlin firmware.
Another possible solution is to reduce the weight of the arm by moving the motor to the base, as Pybot or dual-arm SCARA printers (such as RepRap Morgan) do.