Shaft collars

Part: Shaft collars
Designers: Timothy Schmidt
Tools: 3D printers, Metal lathes
Parts: Nuts, Bolts


The shaft collar is a simple, yet important, machine component found in many power transmission applications, most notably motors and gearboxes. The collars are used as mechanical stops, locating components, and bearing faces. The simple design lends itself to easy installation.




A tolerance parameter was added that can be used to improve the final size of the holes for the shaft, the clamping screw, and the trapped nut. The amount of material to be placed in front of the trapped nut was a new parameter. Finally, a parameter is provided for specifying the number of facets to be used.

Rev A is mostly a refinement in how openSCAD is used, although improvements in the shaft collar result include chamfering of the shaft bore hole and shaping of the bottom of the nut slot to match a hexagon nut. The polyhole function from the MCAD library is now used for improved sizing of round holes. Instead of a single tolerance factor being applied to all dimensions, each parameter can now be individually adjusted. A table of standard dimensions for typical screw and nut hardware has been added as comments in the openSCAD file.

For the clamp to be somewhat flexible, keep the number of solid top and bottom layers to two, and slice with no more than 20% or 25% infill. The overhanging arc over the notch for the screw head may lead to some drooping during printing. Add some support in slicing to prevent it if desired.