So you decided that you wanted to build a catapult. Now it’s finished and ready to fire. Your excitement builds as you pull the release mechanism then, plop. Your ammo sails a few feet and drops to the ground with a disappointing thud. So much for your plans to hurl water balloons at your neighbor on the other side of the fence. You feel the sting of defeat. What went wrong? Why didn’t it work? Do not despair my friend, for I may have a solution to your problem. The next couple of paragraphs will explain a few things that you can do to increase the firing distance of your siege engine.
Check your construction. Make sure your catapult has been properly built. Improperly fitted parts or loose parts can affect the efficiency of your machine. One of the biggest areas of energy loss in a catapult is the pivot points. Anywhere something pivots there will be friction. Make sure the parts move freely, without binding. Depending on your construction lubrication may be needed. If your pivot point is a wooden axle through a hole drilled in another piece of wood make sure it’s not too tight. If the fit is too tight, lightly sand until a proper fit is achieved. If there is too much play replace the piece of wood with the hole in it with a new piece that has a smaller hole. Too much play can also cause energy loss.
More tension! Many catapults are built using springs, bungee cords, or surgical tubing as the source for tension to the firing arm. Beef them up! Replace your existing springs with stronger springs. The same applies to bungee cords rubber bands. Replace the existing ones with something a little stronger. You can also add more springs or cords to the existing ones (double them up). If you have an onager, try winding the cord that is attached to the throwing arm a little tighter. This will increase the tension and force of the throwing arm when it is released. One thing to keep in mind if you are going to increase your spring tension: make sure the framework and firing arm are sturdy enough to handle the increased tension. You don’t want your siege engine to blow apart when you fire it. You may need to reinforce the frame and throwing arm to accomplish this.
All hail the trebuchet! Ah, the mighty trebuchet. It is by far my favorite of all the siege engines. It is far more sophisticated in design than other types of catapults. When properly tuned the distance and accuracy are incredible. Getting to this point can be a real pain in the rear end if you’re not sure what to do. You can build a trebuchet that works, or…
Source by Robert McAvoy