DaVinci Catapult UPGRADE parts

thingiverse

Brian Borken designed a fantastic catapult. I'm a woodworker and therefore really appreciate dovetails. I saw room for some improvement in Brian's design. It's difficult to get the string tied off at a perfect length to provide the power that you want from the catapult. I made 3 "new" parts to make the power level quickly and easily adjustable. The spring is just Brian's spring with small holes at the tops of the arms for the string to pass through. You don't have to print a new spring; instead you could drill small holes in the top of each spring arm as shown in my UPGRADE spring part. The small box is the secret to adjusting power. It has a curved taper inside that matches the shape of the spring arm. It's nice and loose at the top to allow string to pass through. As you slide it down, it will lock the string in place, making it simple to change the power level of the catapult. The string lock has two arrow heads to aid with correct installation. The arrowheads go on the outside of the spring arm and point up toward the top of the arm. Finally, I had trouble getting any payload to balance and fire reliably from the original arm design. I changed the end of the arm to provide a nice spoon shape considerably larger than the original to permit various payloads to be successfully launced. Hope you enjoy. Brian Allen Kuehn.