Inspired by the Canadarm, this Robot arm is articulated, multifunctional, and moves along a gantry. The real thing is used for retrieving satellites, knocking ice off the MIR Space Station, and a wide variety of other things. I chose to go with the astronaut platform with this model, but since it's modular, all kinds of things could be added to the end. In the process, I also came up with a nice position locking feature that allows the arm to be moved into different positions and keep them.
3D printing at this early stage in its adoption tends to be used to create static objects (little plastic skulls and bunny rabbits, for example). This project allows you to explore the robust possibilities with the technology, such as joinery and mechanical movement. Using the Canadarm as a model, this piece is made up of multiple complex assemblies. The pins, slots, tabs, ball joints, and sockets all come together to make a posable finished product that demonstrates the movement of the real robot arm as well as a lesson in mechanics and construction.
I designed the model in Fusion 360 because it's easy to create precise models and keep track of changes. It's also a dream when it comes to 3D printing- just right click on the model, save as STL, and send it to your print utility. Unlike a lot of other programs I've used, I've never had any issues with the geometry translating to a solid printable model. It's also worth mentioning that Fusion is FREE FOR LIFE with a "startup license". All you have to do is download the software, do the 30 day trial, then choose "startup license" and you're good to go with all the features.
Fusion was particularly useful for this project because of its assemblies. By creating assemblies between the parts, I was able to preview the movement of the finished product before wasting any filament.
I printed this project on the Dremel 3D Idea Builder. This machine is a workhorse! I found it to be reliable and consistent with quality prints, and it's much quieter than a lot of the other FDM machines I've used. You can buy one at Amazon, Home Depot, Lowes, or Best Buy.
I wanted the model to be as realistic as possible, so I designed it to be made of a bunch of separate parts that fit together. The parts are...
ROBOT ARM CONNECTION FEATURES
The most challenging part of the design was creating a strong but flexible connection joint for the robot arm. I wanted a standard male / female socket connection that would allow one part to be snapped into the other without hardware, then to be able to articulate and hold its position.
To do this, I came up with a design that used four prongs on the male end of the connection and a trough on the female connection with ribs to allow the prongs to spring past them, but would also be tight enough to hold the prongs in place at rest.
FILES IN THIS STEP: