It’s tough to grip a shaft for a construction project, so give it the clamps. Clampity-clamp clamps. The OpenBeam Shaft Clamp Kit allows you to clamp a 7mm to 16mm diameter shaft anywhere you need it in your design. Take for example, a linear bearing rods in a 3D printer or CNC machine.

These are sold in a pack of four, allowing for both ends of a shaft to be clamped (unsupported cantilever applications are not recommended) and include 4 M3x25mm and 4 M3x35mm hex head cap screws to use as the studs that anchor your clamps to your project.