A-10 30mm GAU-8 Gatling Gun Rotating Desk Model / Pen Holder

BRRRRT!!

A nearly-1:1 scale model of the A-10 Warthog's legendary 30mm GAU-8 Avenger anti-tank cannon with accurate barrel rifling that freely spins using bearings for rotation. As a bonus, a cam in the base causes pistons to ride up and down in each barrel, spinning along the rifling as they do so. Use it as a pen holder, or drop in a scale model of the PGU-13/B to get a sense of the size of the round.

The dimensions of the barrels, barrel center diameter, rifling features, and faux nut on top are all very nearly accurate to scale. Only the outer diameter of the muzzle can itself has been slightly reduced in order to make the entire model printable on a 180x180mm bed (e.g. Prusa Mini+).

Note the entire muzzle can – including the barrels, rifling, can, lid etc prints as a single part, without supports, in the upright orientation. It is a big, long print – good luck – but aside from the long print duration, it should print relatively easily with stock Prusa slice/print settings. I had no issues with any tolerances on the fitment of the pistons in the rifling, bearings, etc.

Print:

• 1 muzzle can
• 1 base w/ cam ring
• 1 retention cap (optional; to glue to the underside of the shaft on the main center bearing)
• 7 pistons - rides on rods and cam ring, spinning in the rifling up and down. Stick a pen, flashlight, marker, etc. in the barrel, and it'll ride up and down on the piston as you spin the barrels.
• 7 cam follower rods - change the overall length as desired for piston ride height.

Buy: 

• 7 bearings - style 608-2RS, 8x22x7mm - to spin each piston on its rod as it rides the cam
• 1 bearing - style 6903-2RS, 17x30x7mm – to spin the muzzle can on the base.

Again, I've included a scale model of the PGU-13/B High Explosive Incendiary (HEI) round also. You can drop this into any barrel on top of the provided pistons, and it too will ride up and down in the rifling as the barrel can is spun around on the base.

BRRRRRTTTTTT!

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Enjoy! This whole project was a just a very random time-killing CAD project over the holiday. Maybe I'll add a crank and drive gear at some point, but my first attempt was all about getting as close to an easy-to-print, accurate, nearly-1:1 scale model as I could on the Prusa Mini+.