Floating Arm Trebuchet

This is a Floating Arm Trebuchet Model that I modeled after variation of a trebuchet by Ron Tom. The mechanism is triggered by two gate latches which hold the counterweight axle in place. When the weight drops (as seen in the pentagonal boxes) the arm travels downward. When the wheels on the arm hit the track, the arm pivots swinging the sting and payload outward.

Dimensions are as follows:

Travel of Track: 20 inches

Base: 10.5 x 22 inches

Arm Length: 32.5 inches

Counterweight: Two 10 pound Scuba diving weights in MDF enclosure

Ammo: Golf Balls and Mouse Balls

Range: From 100 to 200 yards.

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{ 11 comments… read them below or add one }

Devin October 17, 2009 at 10:00 PM

I know you built this trebuchet a while ago, but could you maybe email or comment me about more specific dimensions? I’m thinking of making a F.A.T. also, and I am astounded by how far your trebuchet shoots, considering how small it is, and how light the counterweights are. I could use the dimensions for total high, total length, and the length between the fulcrum and rollers.
Devin O

Maizah October 25, 2009 at 5:10 PM

hey, do you think you can email me some of the dimensions? like how far the wheels are and how tall it is and all of that other stuff? i know you built this a while ago but i have to build a trebuchet for physics and i have no idea what im doing.

Cory October 31, 2009 at 12:13 PM

Do you think you could also email me the dimensions for this trebuchet. Im amazed by the distance that it can shoot.

jared January 15, 2010 at 9:06 AM

could you email me more in depth plans. i am thinking of doing this for a school project and that distance would be incredible

Jason Rashall January 29, 2010 at 8:35 PM

Hello, could you please take some more specific measurements. Maybe lable the dimentions of all the peices of wood? Thank you you have made a really nice machine.


Levi Oja February 22, 2010 at 1:39 PM

I was wondering if you could E-mail me the dimensions becouse I don’t get how it works, and I need to build it for class. thanks alot ,
Levi Oja

vishnulal March 21, 2010 at 12:27 AM

can u send me a detailed description of floating arm trebuchet my email id.

Chase April 23, 2010 at 3:56 PM

Was just wondering if it was possible that you could email me more precise dimensions to your astonishing trebuchet. If you could take the time to do that for me i would very much appreciate it!

Fernando May 5, 2010 at 2:12 PM

Nice build! The distances are impressive. I’d really love to build one myself. Is it possible for you to e-mail me the plans, or put up a link for them?

FAT FAN December 23, 2010 at 12:02 AM

For all you who missed the link in the original text above – here is the link to download the plans for your very own build:


rjones3 December 23, 2010 at 5:42 AM

While I didn’t use these plans, I encourage everyone to follow FAT FAN’s advice.

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