Initial basics for a rotary shaft and housing kept in place with a mechanical prop. August 2024.
Christopher Clayton
08/29/2024
For various potential mechanical motion projects, I modeled the basics of a shaft and prop system after considering what pieces would be needed and how they would connect to each other. I used ViaCad 14 for the 3D modeling process.
The inner tube serving as the shaft housing and the external tube serving as protection were essentially created from three primitives (cylinders) of differing diameters where a starting middle cylinder is kept as long as the other two at first. Then a copy of the innermost cylinder is used in a Subtract Solid operation to hollow out the middle cylinder, and a copy of the resulting middle tube and another copy of the inner cylinder are used to hollow out the outermost cylinder using the same operation. The middle tube is then slightly reduced in length on each end.
The innermost cylinder is also converted into a tube for the shaft housing using a Subtract Solid operation using a copy of a fourth cylinder of equal length but smaller diameter placed in the middle of it. To serve as the shaft for the resulting tube, this fourth cylinder is slightly reduced in diameter compared to the inner tube.
Next comes what serves as a prop or end cap of sorts to keep the rotating shaft in place. This involves creating a cylinder of slightly larger diameter than the entire shaft housing and protection structure. A copy of the latter is used to complete a Subtract Solid operation on the cap cylinder after centering it and placing it deeply enough where its resulting lip will be able to snap into the shaft housing structure's groove when all parts are printed and assembled.
The innermost diameter of this now-hollow cap could be ringed with spherical depressions of sufficient depth to snap spheres into them to act as ball bearings. Only one such cap should be needed on one end because the other end of the shaft will ultimately be attached to an engine that converts energy into rotational movement about the shaft's axis of rotation.
I kept all three pieces in one file, but for 3D printing test pieces or to otherwise create inverted sections of each part to 3D print and assemble into molds, separate files would be used.
