Vorpal Mag 18 Round Back Plate - With Thin Membrane Window

This is a quick & dirty remix of the 18-dart Vorpal Mag back plate with window -- all I added was a thin 0.40 mm membrane to cover the otherwise open window area. Inspired by the thin translucent follower channel on the KaThanha mag.

REQUIREMENT: This means you should print this part using a transparent/translucent filament to allow you to see through the back plate and gauge the remaining dart count in the magazine. You may be able to get away with printing this in a solid colour and still be able to see through it, but there are no guarantees.

WARNING: the thinness of this part means that it is not structurally strong. You may experience flexing. I haven't found this to be a problem myself, but YMMV.

I initially didn't think it was worth publishing this remix since it's basically just a 5-minute job in Tinkercad, but people asked for it so here it is...