37mm 3.5 inch shell casing with built in bushing

I couldn't find a shell that fit my launcher so I designed one. This is a 37mm casing / shell designed to work with a signal launcher, flare launcher. Built in bushing designed to fit 55 grains but make sure you always measure. Fits the primer flush. Interior diameter of the casing is approx 33.4mm.

Tested with both PLA and PETG. Both files are included. 

Settings contain: 6 walls, 5 layer bottom shell with 2mm thickness, 25% infill.

Depending on your filament and printer tolerances you may need to adjust sizing. The primer hole has 2 negative cylinders which you may need to adjust depending on your settings.