Arc Reactor Inner Rings

When I was building my Arc Reactor and I came across the inner rings portion. The inner rings look different than they do in the creators reference images. I couldn't figure out how they were supposed to go into the device. Then I found that the creator, in the comment section, addressed this issue by suggesting that someone heat up some filament with a lighter, and then press it into the inner rings to create this shape.

I have never so much as opened Fusion 360, but I decided I would take