Introduction:
This week we were working with a team to design some sort of machine.
Workflow
Plan: Make a polar 2D printer, using a pen and a rotating surface to draw on pieces of paper.
Design
I worked with Lincoln on the mechanical design of the base. Essentially, we were to create a compact system to rotate a peice of paper in a slow, controllable fashion. We had the following considerations:
Above are some sketches of our design process. The big question we had was how to support the circle throughout its rotation. Our initial idea to do that was to have the motor direct drive it, while having the circle rest on 4 "pegs" towards the edge of its circumference. We decided to use laser cutting to cut out the profiles of our parts. The following were our CAD designs for that.
The original rotating mechanism.
Adding the slots for our dowel pegs to hold up the circle.
With the dowels. We were planning on 3D printing these.
After sending this to Lincoln, he determined that we didn't need the complex support system, and that a press fit directly onto the stepper motor would get the job done. He was able to significantly simplify this design, and my initial prototype was helpful to build off of.
Final Product
From here, the rest of my teammates took it, added the paint dispensing mechanism, the linear slide, and coded it all together. It looked incredbile, and can be found here
And this was one of our final drawings! The software folks did a great job getting it to translate linear points into polar, and drawing something from there.