WARNING! THIS CATAPULT IS INTENED FOR OUTDOOR USE ONLY WITH THE SUPERVISION OF AN ADULT. POSES SERIOUS RISK OF INJURY OR PROPERTY DAMGAGE IS USED IRRESPONSIBLY OR INDOORS. DO NOT POINT TOWARDS PEOPLE OR ANIMALS. DO NOT HOLD DIRECTLY IN FRONT OF YOUR FACE WHILE FIRING. WEAR PROPPER PPE SUCH AS SAFETLY GLASSES OR FACE SHIELD WHEN USING. K-PRINTZ3D IS NOT LIABLE FOR ANY DAMAGE OR INJURY. END USER AGREES TO FOLLOW COMMON SAFETY PRACTICES AND GUIDELINES.

Hey y'all. I decided to design and build a very powerful catapult. Wither its target practice or slaying dragons, this tactical handheld catapult is exactly what you need!!!

Why? Because I was bored and had the human urge to hurl something as far as possible. I also wanted to design something tough using only PLA+ and see how much abuse it could take. So I landed on making a rubber band catapult capable of repeatedly launching a 15.5 gram puck past the tree line in my back yard. Roughly 65-70'. I think its capable of about 100'.

After a couple weeks of testing this is the design I've found to be the most solid and reliable. The larger one in the photos has been fired and dry fired about 120 times and has yet to show any signs of fatigue. It has also been left in the cocked position for several hours at a time without any deformation or warping. The smaller one hasn't been fired as many times but is holding up nicely so far.

Sunlu PLA+ was used for everything.

The Rubber Bands are from a variety pack from the dollar store.

Use the pictures included with the assembly guide(PDF's and JPG's can be found if you scroll further down) for reference on how to tie off your rubber bands.

I'm currently using 22 bands for the full size version and 12 for the 65% scaled version. This will depend on your brand of rubber bands and how strong you want it to be. I suggest adding rubber bands on 2-4 at a time until you find the right amount. The base has plenty of tie off points for you to experiment with.

Everything can be assembled by hand without tools. Be advised, certain fits are much tighter than others, this is by design. If you find that your gripping strength isn't quite adequate when inserting the retaining clips, I recommend using a small set of channel lock pliers. They have a nice offset that can make press fitting the clips easier if needed.

A-Frame assembly needs to be completed before sliding full assembly into the base plate. Throwing arm and trigger can not be added or removed while uprights are attached to the base.

For the trigger reset band, thread it through the third square hole from the edge that sits in line with the trigger. Loop the band around the bottom tab of the trigger and pull it tight. While keeping that tension, cross loop it around the tang coming off the back of the base plate repeatedly until all the slack is taken up. If you have a short enough rubber band, its possible to just pull it around to the tang and be done.

Do not forget to install the pivot bracers. They are the most critical components that keep it from imploding while cocked.

Before installing the slam stop bar, wrap the center tightly and flatly along the chamfered edge that the throwing arm will strike. This will greatly prolong the life of the throwing arm and reduce some of the recoil/noise. See pictures for reference.

If you don't have a Bambu Printer, I advise using at least 5-8 walls and 8-15 top/bottom layers depending on the part.

Pucks should be 55 walls for maximum weight.

Slam stop bar and trigger latch need to be at least 25 walls.

I hope everyone has fun with this one. I'd love to see any mods or remixes. If you can make something that can launch the same puck further you will win my eternal respect. Remember, BE SAFE AND USE YOUR COMMON SENSE!

Be sure to check out my profile for a wide array of designs and projects ranging from planters to lamps. Every like and follow is greatly appreciated so please be sure to. Thank you!