Frizerator H-4

This is the next improvement over the previously published H-3 model. This edition removes the bending stress of the catapult by implementing a $.69 compression spring commonly available from home improvement stores like Menards or your local hardware store. The spring is 5/16" x 1-3/8". Substituting a similar size should also work fine. Keep in mind that the spring force is proportional to the resulting spring speed. CAUTION: Use safety glasses when assembling and opening the cover that exposes the spring.