Trebuchet

My son and I wanted to build a project together, and decided on a trebuchet. I don't remember which one of us came up with that idea.

Working on the long and short arm first

After looking at pictures for design and sketching ideas, we decided to just make what we wanted, using the scraps available. We visited a great web based simulator here
Our goal is to throw a golf ball 150 feet or so, and improve from there. 

 

Working on the basket. (and sweeping)

Wheels, basket, bearing caps, etc. 

  

Cart is done, working on the stub axles and mounting thrust washers and wheels

White Oak perpendicular bracing for the main axle

  

Bearings pressed in and covers fitted

 The 5/8 steel rod are supported on roller bearings, the kind for garden carts. We invested $30 or so for axles, bearings and hardware.

 

Ready for assembly and bracing

Assembled and glued up.

 

The main project is mostly done, just waiting for a buddy to finish the sling pocket. We will fashion a simple trigger mechanism and runner for it then.

The swing test below was done empty first, then with about 22 lbs or so of rocks in the basket. One improvement in the future will be weight that is more stable in the bucket, and doesn't shift. 

 

 

 

Look for our launch tests in the future!

   

About 55 feet with 20 lbs weight and a makeshift sling.

Update: Trigger mechanism, tray for ammo and leather sling all assembled. 40 lb weight is now cemented into the bucket. Averaging about 120 feet for the typical shot! The last video shows a shot before the application of the trigger.