The motor mount of the model rocket is used to secure the model rocket motor in place inside the body tube. We will be constructing the motor mount from two rings connected by posts. The top ring will have a hole for the ejection charge of the rocket motor. The bottom ring will have a hole for the nozzle at the bottom of the model rocket motor. We will start our motor mount design by taking measurements of the paper tube.

Building around the paper tube

For those familiar with model rocketry, it is quite often the case that a simple paper tube from a paper towel roll does not fit with existing model rocket parts. However, with OpenSCAD and a 3D printer, we may custom build parts to fit any paper tube. We will design our nose cone, fin can, and motor mount around the paper tube, starting with the motor mount.

To design the motor mount, we need to get an accurate measurement of the internal diameter of the paper tube. To do this, we will build a measurement...