Printed solid so it would hold up to wear and tear. I think I had to scale the core down a percent or two for it to actually fit, as the design tolerances were very tight. Once scaled, screwed together pretty well, and the prints that did not screw together easily I just used a dab of silicone lubricant to help get it working.
Monoprice Maker Select V2
Printed in white Monoprice PLA