(For some reason or the other i stopped taking pictures half way through, but I'll try and explain what else I did.)
Step 1: Planning
Step 2: What You're Gona Need
1- 1 foot, 1/2 inch diameter bolt with two washers and a nut
1- 1/2 foot 5/16 inch diameter bolt with two washers and a nut
We also used a bunch of junk that I had lying around in my basement. You might need to purchase these items if you dont have them...
2- 25 lb. weights (from a benchpress)
Cloth for the sling pouch
Rope or chord of some type
A big washer
A finishing nail
A saw (a chop saw works best)
Like I said, we were wingin' this entire project so you might need to improvise here and there.
Step 3: Building the Frame
O yea...probably the most helpful thing you can use during your trebuchet construction is clamps. Even if you're working with friends, a good set of clamps are invaluable.
Step 4: Making the Base
Step 5: Aattaching the "A's" to the Base
Step 6: Building the Arm
Holes need to be drilled similar to the places shown in the picture, for the axis, and also to hold the counterweights.
The ratios for the axis point and the center of the counterweight is 4:1, so if yo decide to use a 4 foot long arm the counterweight needs to be placed a foot behind axis.
When we tried to fit the counter weights inbetween the pieces of 2x2 they didnt fit, so we had to shave the insides off to allow them to fit nicely.
Note: The arm we constructed for our trebuchet wasn't exactly how it should have been according to the correct ratios. When constructing your own arm make sure that from the center of your counter weights to the main axis point is one foot long, while from your axis point to the end of the arm is four feet long. The long portion of our arm ended up being about 8 or so inches short because we didn't account for *this* (look at the second picture) section of the arm having to be connected to the other 2x2's.