CNC Milling Machine Spindle

My first post! Hello everyone, I designed this CNC Spindle for education purposes and it serves as a model of a working spindle and moving draw-bar used to release and grab tools in CNC machining. The design is for educational purposes and does NOT directly reflect actual Spindle design.

The bearings are loaded with roughly 40 "3/16" delrin balls and work wonderfully. The inner shaft houses the R8 collet which has 1/4-20 bolt threaded into the R8 collet where the spring applies an upward force clamping the tool in place.

These parts were printed at school on a very expensive machine and have the highest detail possible which is why my STL files are large. It took 23 hours to print the parts.

If you want to finish this project, there are some extra holes to be drilled and threaded if mounting a motor etc.