How to Design Twisty Puzzles - (Part 8) - Cores and Center Caps

[@samlwh8532]

I plan on doing a 6-armed core with strengthing ribs like the GuoGuan YueXiao, while still making an empty spherical space inside for anti-pop features like torpedoes. How do I do that?

[@EPICGUYDUDE]

I used 2.4mm for M3 screws, is that way too small?

[@laiscube]

How long are the screws?