A small 3d printed cam toy likened after Oscar the grouch and a penguin made for MAT238

Supplies

Fusion, Prusia

Step 1: Design in Fusion

Starting with a template that included the sides of the box, the shaft, basic cams, and the handle, I designed the characters by manipulating the vertices of different surface objects and combining the result into one body. I started with the trash can and then the "Oscar" character. I didn't really bother attempting to make the character actually look like Oscar the grouch. I then created the lid and the penguin. I had some trouble after created the bodies when I tried to make sketches on the surface for attaching the solid geometry necessary for the connection points between the objects. The remedy involved using a surface box with almost flat sides imbedded in the bottom of the character. I could make a small sketch on that surface and then extrude it out to make it the larger block that I wanted.

I added tolerances so the piece would fit together snuggly or move freely. The tolerance for the movement (0.5mm) was good, but the tolerance for the parts that should be snug (0.3mm) was way too big. I had to use tape to get the cams to stay put. Also the design did not provide enough vertical support for the cam followers. so it was basically impossible to get them to stay positioned on the cams. The box needs a vertical shaft for the cam followers to slide within that keeps them vertical. I tried to use tape to narrow the small square guide, but it didn't really work.

Step 2: Assembly

The toy went together ok. The walls and floor fit well and the shaft moved freely. The issues with the cam followers basically made the movement impossible. Also, the cams need some reshaping and sanding in order to be smooth enough that the cam followers don't get stuff on the changing profile.