turning and beeping TF2 sentry gun

USB-powered sentry with space for a 28byj-stepper, 30mm-ish speaker, and electronics. the lid of the magazine can be removed. the stepper needs to have the screw hole tabs trimmed down to fit.

demonstration: https://www.reddit.com/r/tf2/comments/g6qm0q/3d_printed_sentry_gun_mk2_now_turning_and_beeping/

it is a highly modified version of this: https://www.thingiverse.com/thing:1013775

arduino code: https://www.dropbox.com/s/dy9kibuqtffktd3/sentry_beep.ino?dl=0