Assembly Video: https://youtu.be/xnxla2OM4N0
V5 fire test (reliable with up to 10 bands, let me know if you can do more!): https://www.youtube.com/watch?v=4ujVGXZd8H8
Too complex? Bed too small? Made this 6 shooter that's wayyy easier: https://www.thingiverse.com/thing:4753071
UPDATES V6 - Fixed firing reliability issues across the board. Made assembly easier, bands don't need convoluted mounting any more. Made the design easier to print. Dozens of small tweaks... this may be the final version, we'll see after I make 2 and test. V5 - Display Stand, nubs on top to keep the bands a bit separated so they don't pinch the release catch, fatter release for wider bands, magazine tapered and smoothed at the corners to help with band release V4.1 - Small bed version added (front and back pieces) V4 - Less tweaking needed to get full auto working, smoother operation, left and right hand versions, NOTE, Elastic release may be updated shortly, trying to get the full auto to be more reliable so changing the angles a lot. V3 - Complete overhaul of internals after testing, way more reliable now V2 - Shoe mechanism changed for rocker, doesn't 'mag dump' or double fire in full auto now.
Subscribe to: https://www.youtube.com/c/Props3D if you want to see the video when it comes out.
This works by loading bands onto a rear rotating square magazine which is kept from rotating forwards by a rocker. Note: Load the magazine with the bolt locked forward to prevent it from hitting the rocker.
When you release the bolt it will cycle backwards knocking a bulge on the rear of the elastic catch into the rocker causing it to rotate a quarter turn. This will load a band onto the catch, which is then held in place by the bolt getting stopped by the trigger sear. When you pull the trigger, the band on the catch pulls the bolt forward and releases the band towards your target, then another small band on the bottom of the catch pulls the bolt back and the catch hits a shoe again allowing the magazine to rotate another quarter turn. This repeats with a satisfying noise, the bolt cycling back and forth like a real open bolt SMG, and lots of rubber flying towards your intended victim, and good fun is had by all hopefully.
Holds 8 rounds one at a time or 1 15 if your really feeling lucky (V4 made this much more feasible). I MAY try a hex version that will increase capacity by 50% in V6.
V5 Non 3D printed parts list:
M3x812 Screws - Goes into body below mag catch
M3x68 x2 Screws - Holds connecting rod between bold and band release
M3x16~20 Screws x10 - Holds the whole thing together, self tapping
Loom sized band x2 - Goes around that screw and over mag catch to hold it down | Goes over bottom of release and post behind trigger to keep rear tension on bolt
3mmx20mm rods x5 - Through all moving parts
Bic pen spring - goes in small channel under sear to provide upwards pressure
Interesting in seeing some of the props I sell? Check out my Etsy store: https://www.etsy.com/ca/shop/Props3D
See my projects and how-to videos at: https://www.youtube.com/c/Props3D