When I designed the Penny Catapult to fit on a Replicator1, assuming that printers were only going to get bigger. But the new crop of smaller, inexpensive printers coming down the pike requires a Seej engine that can be printed on a smaller build platform.
Enter the Marshmallow Mangonel. It’ll still throw a penny, but includes a second throwing arm designed for non-coin projectiles; marshmallows, gumballs, magnets, whatever you’ve got lying around that needs to be parabolized. You can find the Mangonel and its bigger brethren in the Seej Engines category in The Forge.
If this is your first exposure to Seej, head over to s33j.net and grab yourself a starter set. Get printing and then get your tabletop wargaming on.