How to model retainer cage of ball bearing?
Here are a few steps and the uploaded model: Bearing cage demo
Open the model and look at each step to see how it was done.
First create a ball and then an intersecting axis using the top and right planes
Create a circular pattern of your balls around the new axis
Sketch a band on your front plane
Use mid-plane to extrude your cage band, but UNCHECK the "merge result" box
Sketch a slot on your top plane and make a cut through only your band by selecting on the band as your cut body
Make a circular pattern of the previous cut around the same axis using the same number as the balls you patterned
This should complete your cage