This week, we designed and built a machine capable of drawing based on uploaded documents and code.
The machine uses rubber treads to move an end effector in the x-y plane, while the end effector itself can lift a marker in the z direction. The idea was to create a versatile system that could draw precise shapes or patterns based on user input.
The completed drawing machine.
My main responsibility was to design and work on the end effector. The concept we developed involved mounting the end effector to the rail that moves in the x-y plane. The end effector would use one servo motor with a gear to move two rack-and-pinion mechanisms on either side. One side held a marker facing downward, and the other side held an eraser. Rotating the gear would raise one side while lowering the other, allowing the machine to switch between drawing and erasing.
Initial CAD design of the end effector.
Side view of the CAD design.
This was actually our second iteration of the end effector design. Our first iteration encountered several issues, including instability in the z-lifting mechanism and misalignments in the rack-and-pinion gears.
The first attempt at building the end effector.
Unfortunately, even with improvements, our second iteration still did not function as intended. We worked on refining the CAD late into the evening, but ultimately, we decided to simplify the design. The final end effector only held the pen in a fixed position without any lifting mechanism for the z direction.
The simplified end effector holding the marker in place.