Some tips for building a tabletop trebuchet include using a heavy counterweight and tuning the trebuchet for accuracy and distance. Although many plans call for using hardwood, working trebuchets can also be made from balsa wood and popsicle sticks.
Unfortunately, one of the most important aspects of building a tabletop trebuchet, adding a counterweight, is also one of the last steps in the process. Gather common objects such as fishing weights, sections of metal pipe and other non-breakables that can be bundled together with duct or packing tape.
The trebuchet may throw its payload harder than you expect, so include strong twine, very light-weight chain and old leather belts with your other materials. You also need a strong glue such as a fast-drying epoxy or wood glue, nails, wire or jumbo paper clips, material such as burlap and canvas to make a sling for the payload, and wood. Maintaining small scale is important so that the trebuchet does not cause damage. Popsicle sticks make strong, conveniently sized pre-cut pieces.
Once the wooden part of the trebuchet is assembled and ready to test, put together the sling, and load it. Fire the trebuchet several times to test its range with different counterweights. Tune as necessary to improve range and accuracy.