You want a reliable, easy and inexpensive way to trigger your catapult or trebuchet? I have the solution right here. This idea was sent in to me by a web visitor (Daniel) who built my tennis ball trebuchet. My thanks go to Daniel for this terrific idea.

Here is the trebuchet that Daniel made.

And here is a close up picture of the clever latching/triggering mechanism that he added. It is a gate latch that you can cheaply buy at Lowe's or Home Depot. And I have also added a link if you want to get it on Amazon.

Below the picture is more about how it works.

The gate latch comes in two parts. A bar and a latching mechanism. You mount the bar to your trebuchet arm, and you mount the latching part to the base of your trebuchet. Pretty simple.

And notice one thing in the picture. There is a string going from the latch through an eyelet screw. This is so that when you pull the string it pulls the latch, opening it and allowing the trebuchet to shoot!

And the way this latch works, after firing it, you just bring the trebuchet arm back down and the bar will automatically lock back in. Ready to be fired again.

It's a nice setup that will make your trebuchet or catapult a whole lot easier to use!
My thanks go to Daniel for the idea and the pictures. I have sent him a certificate of contribution :)

This exact gatelatch is available on Amazon. At the time I posted this the cost is six dollars and change. Check it out right here. (You can also run down to Home Depot or Lowe's and get one of these. It is a very common part.) Well, you probably shouldn't run. Just drive your car there.