How Can I Improve My Catapult?

So I built a mangonel (torsion catapult) for science olympiad, and it must launch a foam ball up to 15 meters. But, its struggling to reach 10 meters. I was wondering how I can make it launch further, whether changing the tension of the torsion bundle, different rope, or even structural changes. I will gladly accept any and all suggestions.

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Triclaw3 years ago

move the stop to the back side not the face and cut a grove to sink the arm into the base. give the arm more room to travel and should make the 15 no problem

rickharris3 years ago

This is not going to sound like much of an improvement but trust me - Do the other things AND put it on free turning wheels.

This makes a considerable difference. I will leave it to you to find out why.

sean_sylvester1 (author)  rickharris3 years ago
I actually laser cut acrylic rings this afternoon, and I plan on using those for washers so that I can turn the handles a few more revolutions.

More tension on the torsion bundle is a start and using a natural fiber cord for the bundle would be better. You want a material with vary little streatching to it.

sean_sylvester1 (author)  mpilchfamily3 years ago
I'm currently using nylon (the picture was a prototype). So what organic material would work better?

Any natural fiber rope like hemp.

Longer throwing arm ?