This is an opensource flywheel cage created for the Nerf Hyperfire.
There are four versions of this cage poster here, for highest performance print the 41.5 mm cage. Each cage larger has decreasing performance related to the gap distance listed in the file name.
For high crush systems such as the 41.5 mm and 42 mm cages, motors with very high torque ratings are required.
You can use rafts if you want, However it will require considerably more post processing that way.
This can be printed in PLA, but due to the high heat generated by the motors, it is best to print in ABS or PETG.