Replacement handle for Konix Speed King.
The inner hole in the first print was probably a bit too deep (doesn't matter that much with flexible enough material). I added M2 nut to keep it slightly higher.
Since Form 2 has rather nice resolution, I made the polycount rather high, as I wanted the handle as round as possible.
The uploaded model has slightly less deep hole, but haven't tried 3D printing that yet. (And current version is good enough anyway...). If you need, you can adjust it further in the included OpenSCAD source.
With durable resin, the stick seems to fit tight enough.
Can't say much about durability yet (haven't tried Decathlon yet), but it feels that the material will likely bend, rather than snap.
Printed in durable resin. I let software decide the orientation. For other technologies, no idea which might be the optimal orientation. Probably you need some supports.