Rubber Band Shooter with 21 Slot Magazine 3D print model

Made by: LoboCNCPublished on: https://www.printables.com/pl/model/287875-rubber-band-shooter-with-21-slot-magazine/filesNo glue, no screws, just add rubber bands!Funny how when you make a rubber band shooter, you suddenly have no rubber bands. This shooter will certainly make them go missing in a hurry.Unlike most styles of rubber band shooters (paddle wheels, rack shifters, etc.) the radial array of bands allows for extremely high density while also maintaining a constant band tension and trigger force. The removable magazine can hold up to 21 bands and can be swapped out quickly for heated rubber band battles.The mechanism uses a worm and gear for both advancing the magazine and for releasing each band. Pulling the trigger causes an internal rack to engage gearing that rotates the worm ¼ turn. The worm indexes the magazine while the leading edge of the worm thread pushes the next band off its little hook. The worm has 4 threads, so each ¼ turn advances the magazine by one tooth.The trigger itself is another interesting mechanism. When the trigger is pulled, the little blue cam (hiding behind the rack in the 6th photo) pushes the rack up to engage the lower gear. Continuing to pull the trigger advances the gear by ¼ turn. But when you release the trigger, the cam flops down and lowers the rack as the trigger returns to keep the rack from reversing the gear.PrintingI highly recommend printing this in PLA. There are a couple of internal leaf springs, and there's no guarantee they'll work properly if printed in PETG , ASA, etc.. I recommend 0.2mm layer thickness. Print one of each part. No supports are needed, but note that the rack has a small built-in cylindrical support hiding in the little pocket where the cam goes. Remove that support with needle nose pliers after printing. Test fit all the parts before doing the final assembly. Run all the moving parts back & forth against each other until every thing moves smoothly.