I did something similar. I basically drilled out a hole into some nylon spacer tubes to fit the magnets. I then glued them inside. After curing I took a 1/2" ball nose cutter and made the groove to contour with the 1/2" balls until I got them very close, but never touching. I then glued the spacers on each end of the carbon fibre rods and made a jig so that all of my rods matched. I have the 1/2" balls glued to the end effector, and the brackets at the top. And so the rods just clip in both. I have yet to see them come apart even in high speed high accelerations. the strength of the magnets is really good I have yet to see any of the rods shift around. Best of all, I made the end effector changeable by just taking off the rods and disconnecting the quick disconnect for the electrical.
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