20mm Diameter Ball Mold (for slingshot ammo)

thingiverse

I love slingshots, but having uniform ammo is the challenge. Marbles are cheap, yet they leave broken glass everywhere. Steel shot (ball bearings) is pricey, but a magnet makes retrieving ammo easy. However, I'd rather not do that. What I need is biodegradable disposable ammo that's dense enough to take down a jackrabbit. My plan is to make a metal mold that can be heated up. Then, I'll blend my PLA rafts into powder using a blender and mix it with sawdust from the woodshop. Next, I'll compress this mixture with a hydraulic press into the heated metal mold. In the meantime, there's an RTV mold making class and a carbon fiber class every other week at the local TechShop. They always have leftover RTV or resin after the classes. So, I made this mold to utilize the usually wasted material. The RTV balls hurt like crazy and leave a nice little bruise on my intended victims. Personally, I prefer 20mm diameter spherical ammo for my slingshot ammo. I have big hands, and ammo smaller than 15mm is a pain for me. Plus, there just isn't enough mass to hunt anything significant. So, I tend to make ammo about in 15mm-20mm diameter spheres. I designed this mold on TinkerCad because it's so easy to use that I can get my ideas out faster and easier than in a parametric cad/cam program. Here's the link to the files: https://www.tinkercad.com/things/4izNkjRnmsV-20mm-ball-mold/editv2?sharecode=wQqav2OqwpUzCW_hGllUokjeetJ9BiTrGIkQpWCfYH8= So, you'll need to print two of these mold pieces. They should mesh perfectly together. Eventually, I'm going to add a luer lock directly into the mold so that you can take a syringe full of material and connect it to the mold and inject away.