20mm Diameter Ball Mold (for slingshot ammo)

thingiverse

I love slingshots. But the challenge is having uniform ammo to shoot. Marbles are cheap but they leave broken glass everywhere. Steel shot (ball bearings) is not cheap, but with a magnet you can retrieve your ammo. But I'd rather not. So what I need is some biodegradable disposable ammo that is sufficiently dense enough to take down a jackrabbit. So eventually my plan is to make a metal mold which can be heated. Then I was going to take my PLA rafts and powder them in a blender, then mix the powder with sawdust from the woodshop, then compress that mixture with a hydraulic press into my heated metal mold. But in the mean time, there is an RTV mold making class and a carbon fiber class every other week at the local TechShop. They always have left over RTV or resin after the class. So I made this mold to utilize the usually wasted material. The RTV balls hurt like a son-of-a-gun and leave a nice little bruise on my intended victims. Personally I like 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 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 will 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.