The Doom Trebuchet!

thingiverse

For my 100th Open Source project posted here to Thingiverse (Yay!!!!!!), I wanted to create something fun for this community that is sure to delight. And what could be more enjoyable than a device capable of launching a gummy bear across the room with sufficient force to slightly dent a wall (maybe, if you look really closely?)? This design utilizes numerous fender washers, some string, metric bolts, bearings, tape, wire, and heat-set inserts to craft the feared medieval contraption. At any rate, please enjoy this creation, and thank you for liking and supporting my other work. It means a lot to me that people appreciate the things I create, and your comments and messages over the years have been great encouragement. This one is for all of you! Video: https://youtu.be/4ZHNv2MBay4 William of Materials: 1 64mm M8 bolt and nut 1 64mm M5 bolt and nut 5 m3 10mm cone head screws with 2 nuts (non-locking) 8 14mm M3 cone head screws 4x 14x5x5 bearings 2x 608zz bearings 2x M8 washers A metric ton of M5 fender washers A 200mm length of threaded M5 rod (or similar English size) and 4 regular nuts 4 nyloc nuts to fit your threaded rod 2 finish washers to act as buhings against the frame 1 small metal ring for sling 2 small pieces of wire, one to make the sling hook and one to make the release trigger Some plastic packing tape to make a sling Some black thread to make a sling 15 M3 heat-set inserts 4 10mm M3 cap head bolts 9 rubber stick-on furniture feet Instructions: Print all parts. You will want to end up with four legs, so print that file twice. 1. Insert six heat-set inserts into the base plate: four at the corner lobes and two in the centerline holes. 2. Insert three heat-set inserts into the bottom of each main frame side. 3. Insert three heat-set inserts into the holes in the lower throwing arm. 4. Bolt the chute to the base plate using two cone head screws with the non-locking nuts. 5. Make a trigger pin out of a metal rod and some string. 6. Now construct your sling. When folded in half, the sling should be about as long as the length of the throwing arm down to the two side wheels. You should now be ready to test fire! Troubleshooting your trebuchet: If the sling does not seem to open, adjust the angle or length of the pin. My pin is pretty close to ideal, so you can use the pictures as a guide. If the projectile doesn't go forward, adjust the angle of the pin, or consider shortening the sling. If the flappers don't fall down, loosen the side screws slightly, or trim them to fit better. If you accidentally shoot your sibling in the eye, don't do that! It's all fun and games until someone loses an eye, then it's just fun! All the STEP files are uploaded, if you need a different format for some reason, please don't hesitate to ask! Also, stay tuned for the laser target designator attachment and the picatinny scope mount!