This is a project that I've been working on for a little bit. The goal is to develop a fully 3d printed set of flywheels for HIRs. I know that others have tried this and the general consensus is that 3d printed wheels will not last due to the shaft holes wearing out quickly but from what I have seen most people have just been using PLA and I haven't seen much experimentation with PETG. Maybe it's not possible but I wanted to give it a try before I call it quits. So far I've tried two types of flywheels. One version has the wheel made of PLA with a PETG shaft interface, and the others are fully printed in PETG. From the testing I've done so far, I think it is possible to print decent wheels but we'll see.
If this project succeeds, I plan to release the files for the cage and wheels so that others can make some custom blasters or something.