Techbot Toy

3D prototyping for an independent project

Purpose & Role

In an effort to explore how to create a ball and socket joint using a 3D printer, I created a series of 3D prototypes of TechChange's TechBot character. As this was a personal exploration, I independently conceptualized and sketched the 3D specifications, developed the SolidWorks model, and printed the .stl files using an NVbot 3D printer.


I started brainstorming how to transform TechChange's 2D character into a 3D format by analyzing images of TechBot provided on TechChange's website. Based on these inspiration images, I arrived at measurement specifications based on two strains of logic, one design and one technical. On the design side, I wanted to be able to hold the 3D character in my hand so that it could function as a toy. Technically speaking, the 3D printer I was working with could only print objects up to 8 inches in height and 7.5 inches in width. Additionally, printing was slow work. The smaller the object, the faster the process of iteration would be.

My inspiration image (via TechChange).
My initial sketch of 3D specifications.

Given these overall specifications, I decided to try out a ball-and-socket joint in which the ball would be attached to each arm and the socket would be cut into the body of the character. To enable the ball to fit into the socket opening, I created cuts in the ball in order to allow for some bend in the shape. The trick was to figure out what size of cuts would be optimal for the material of the printer as well as the precision possible with the printer.

A screenshot of the assembly in SolidWorks.
A screenshot of an initial .stl file of the body piece.

At first I tried four wider cuts in the ball. While this attempt enabled the ball to squeeze into the socket, the arm was too loose. I tried again with six smaller cuts. However, the cuts were too small for the printer to output effectively — each cut ended up being printed with support material as they were too weak to be printed without it. From these trials I concluded that it would have been more successful to print the ball within the socket on a printer that has dissolvable supports.

Although the ball and socket joints didn't turn out as well as I had hoped, I was able to create a wheel and rod assembly such that the character could sit down on the base of the body. With this detail, I was happy with how the final result resembled the original 2D character.

The final printed character, sitting down.
The final printed character, held upright.