Fox-1B or RadFxSat is an amateur radio satellite constructed by AMSAT (the Radio Amateur Satellite Corporation) and launched into low Earth orbit on a Delta II rocket from Vandenberg Air Force Base on November 18, 2017. After successful on-orbit operation, it was designated AMSAT-OSCAR 91, or AO-91. Much more information about AO-91 is available at http://www.amsat.org

This is a life-size scale model of AO-91 designed for 3D printing. It is based on the actual design files for AO-91, but some difficult-to-print details have been omitted, including the antennas.

Ultimaker

Ultimaker 2

Yes

No

0.15

20% (not critical)

The whole cube as a single object is a huge thing to print, and there's no way to print it cleanly without support material. STL files for the six individual faces were created to solve this problem. Each face can be printed with the flat inside surface down, and get the best results on the visible outside surfaces. Then the faces can be glued together to make the cube model.

Glue the six faces together at right angles to make a roughly cubical model. It should be fairly obvious how they are supposed to go together.

I started with a set of CAD files created by AMSAT team member Bob Davis to capture the actual physical design of the spacecraft. This model contained every screw (with threads modeled), the two bent sheet metal pieces that form the chassis (with holes and countersinks modeled), the six circuit boards with solar cells and other components attached, the eight machined corner pieces, and so on. It didn't contain all the internal parts of the spacecraft, but it did include many parts that would not be visible in the final printed model. The CAD model, like the spacecraft, is largely hollow and open to outside vacuum.

To make it printable, I brought the exported CAD file into Fusion 360. I eliminated most of the holes and hollowness by modeling a solid cube that matched the dimensions of the innermost visible surfaces. The cube had to be modified to preserve certain details, such as the Phillips screw heads. Some of the external objects in the CAD model (solar cells and their connections) had to be modified to actually touch or intersect with the inner surfaces. Other external objects would not have been printable and were simply deleted. Finally, all the remaining CAD objects were merged with the solid cube to create a single solid model of the satellite.

The single solid model is theoretically printable, but not very practical. To make a more practically printable design, the six faces of the cube were sliced off using construction planes to create a minimum thickness of 5mm.