Lot's of people ask me how much my counterweight actually weighs. It is important for the Trebuchet to have something really heavy as the counterweight. But not everybody has a solid metal ball like the one I used. My usual response is that you should make it as heavy and as the room in the Trebuchet allows.

But, to get a sense of what my counterweight weighs I needed to weigh it on a small scale and I don't have one. So rather than take a trip to the grocery store and use the lettuce scale I just made a little Mobile like scale, balanced it out nice then used pennies to find out how much the ball weighs.

It comes in at 147 Pennies.

Here is the kooky Trebuchet counterweight scale:

I first made the seesaw bar and then to balance it I put a little masking tape on it. Then I added the cups, using the same lengths of string for each and voila! It was done.

Put the counterweight in and then added pennies until it balance: 147 pennies for my Trebuchet counterweight. Gives you a good idea of how heavy your counterweight should be.

***So what is the Optimal Weights you should use for your trebuchet? Well, this will vary depending on the size and strength of your build but there is a secret formula you should know! It is the ratio of 133 to 1. That is considered to be the optimal weight ratio for a trebuchet! So, if you were going to use a penny as a projectile 133 pennies are what you should have in your counterweight!

So how do you use this little scale set up to get the right weights for your projectile? Lets say you are going to put 133 pennies in your counter weight. Now you just need a projectile that weighs 1 penny. so put a penny in 1 side of the counterweight then put a ball of paper in the other and make it a ball that weighs the same as the penny. Tear it up and make it larger or smaller until you get it right. I highly recommend you don't use a penny as a projectile, it is dangerous.

Want to go heavier? Try 133 nickels! Then make a paper or clay ball that weighs the same as 1 nickel.

The Behemoth: Ten foot Trebuchet

This is monster of a Siege engine. I have instructions on how to build one, more pictures and a video showing it launching a six pound rock. Nice project. (the tutorial is not yet done) Check out the Behemoth Trebuchet here