GATLING RUBBER BAND GUN

UPDATE: NOW HOLDS 80+ RUBBER BANDS, ADJUSTED THE BARREL & BODY!

I first encountered this in a wooden toy shop located along a major interstate during one of my mom's business trips in Northern California when I was about 8 years old. The shop, reminiscent of Santa's workshop from the early 1980s, was filled with handmade creations, including this skillfully crafted wooden toy that I still remember to this day.

Most of us don't have the space for a wood shop these days but we do have the space for a 3D printer.

RUBBERBANDS: Amazon.com : Foshine-Rubber Bands size 32,Elastic band beige size #32 rubber band 210pcs small rubber bands office supplies(3" x 1/8'') : Office Products

STRING: Amazon.com: Twine String,500 Feet Cotton Butchers Twine String Cooking Kitchen Twine for Crafts Roasting Gift Wrapping DIY Decoration Gardening Packing Materials,Black : Tools & Home Improvement

The body, crank arm and rods were printed in ASA and the barrel and body rod clip were printed in PA.  

INSTRUCTIONS: 

1. Have a look at the last picture. The picture shows the arrow located on the back of the crank arm. As long as the arrow is facing back and pointing up on the arm the rods will be threaded in the right direction to spin the crank forward.

2. Insert the crank assembly into the body and slide the clip down into place. The clip is a tight fit. Once installed its very difficult to disassemble.

3. Cut a piece of string roughly 8' long. Simply start wrapping the string (see close up picture) around the barrel about ½" from the base works best, but its not an exact science, wrapping the string back down towards the base of the barrel placing a rubber band over each spine as you go, you can only wrap the string around the barrel around 8 times before it gets over loaded and starts miss firing rubber bands.

4. Place the barrel onto the barrel rod and thread your string through the guide hole and under the body rod. Tie one or two knots in the end of the string and place it into the string slot. Spin the hand crank forward to take up any slack in the string. The barrel is held onto the barrel rod with the string tension only. 

5. Have FUN!!

PRINTING INSTRUCTIONS:

load the .3mf file(s) and print using the appropriate filament.

My Settings:

PA/Nylon:

Flow ratio:  0.94
Max volumetric speed: 4mm3/s
factor K: 0.020

ASA:

Flow ratio:  1
Max volumetric speed: 9mm3/s
factor K: 0.015