V8sr4u

I currently have access to two 3d printers and found an interesting idea on thingiverse. I searched flywheel cages and found a multistage setup. I recently broke my bb Brute, so I thought I might go with a multistage, since I think I need new motors and micro switches. I was thinking rhinos and I found some switches. I thought about using two lipos with resistors for the multistage setup. Do you guys think a multistage setup is a bad approach?

I recently modified the design for a stock adapter for the buzz bee thermal hunter. Today I saw some Nerf attachments and it got me thinking about, what if me or somebody made a barrel with the Nerf barrel attachment point and made a rail for the thermal hunter that just replaces the rail on the gun, but is a Nerf rail. Also, it would be quite helpful if anyone knows what the biggest spring the thermal hunter can take and the first thing that breaks with too big of a spring. The priming bar looks like it would go, but I didn't know if there was something weaker. What do you guys think?