If you’re looking for plans on how to make a catapult, here’s a simple design that’s easy to make. It’s surprisingly powerful and easily accommodates variations. Best of all, you can make this simple catapult out of household items. Here’s how to get started:
-Coffee cup with handle
Note: Coffee cup must be a cylinder. It cannot be oddly shaped. (figure 1)
What to Do:
1. On a tabletop, lay your coffee cup on its side. The handle should be in the down position, resting on the tabletop. Now tape a pencil (your fulcrum) to the top of the coffee cup. (In actuality, this is the side of the cup, but you have the cup resting on its side so the top is now the upper most position.) (figure 2)
2. One at a time, wrap approximately six (size 64) rubber bands around the coffee cup so that a belt of rubber bands is formed just below the pencil (on the side nearest the coffee cup handle). (figure 3)
3. Turn the cup over so the BOTTOM side is exposed. Be sure the rubber bands (that you just wrapped in step two) are aligned with one another. Now secure the rubber bands to the BOTTOM side of the cup with tape. (figure 4)
4. Return the coffee cup to its original position so that the pencil is once again in the uppermost position. Now slide a teaspoon under the belt of rubber bands. Slide it just far enough so that the mid-point of the spoon is resting on the pencil. (figure 5)
(See how this catapult compares to other catapult designs on this site.)
5. Slide half of the rubber bands (in this case three of the six) down the teaspoon handle. Rest them near the bottom tip of the spoon. (figure 6)
6. Secure the three lowered rubber bands to the bottom tip of the spoon with tape. Do this by folding a piece of tape over the bottom tip of the spoon and pinching it firmly so the rubber bands are securely fastened. (figure 7)
7. Your catapult is now complete. (figure 8)
How to Launch Stuff
Simply place launch item in the cup of the spoon. Pull spoon back over the fulcrum then release.
Optional: For added stability, tape the catapult to a cutting board. This will make it easier to steady the catapult during launch.
Variations on This Catapult Design:
a. Use a different fulcrum such as three pencils (instead of one), a tube of lipstick, a marker, a cork, etc.
b. Secure the fulcrum in a different position–slightly forward or backward.
c. Use a different number of rubber bands.
d. Change the number of rubber bands that are lowered to the bottom tip of the spoon.
e. Use a different length of spoon.
Of all the catapult designs on this site, this one may have the greatest output for the least effort. In other words, when you consider how few materials are used, how ordinary those materials are, how easy it is to make this catapult. . .and you compare that to the launch power, consistency and durability, this model rates very well. Whether it’s for science class or just weekend fun, I think you’ll have fun with this design.
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