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Catastrophic Catapult


CoreyK

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Well… we tried….

These three words were the resignating theme at the end of an 8 hour day of sawing, screwing, welding and re building our catapult. At hour seven we decided that we need to make a lock for the monstrous contraption. A hand full of welds later and a spark or two down then sleeve it was all set up, ready to test and even more ready to say it was finished. The weights were set, the bar pushed up, and the pin holding it in place.

It was marvelous, the seven hours of work was all worth it. With one tug on this rope the pin would come out and are creation would come to life. Yeah… no. Now quite.

The weight on the arm pushed down too much on the whole that the pin was put into, so no matter how hard we pulled it just would not come out. Friction was the answer! So much weight pushing down on the pin from the wood hole that the surface area holding the pin down because of the weight exceeded the force we could apply to pull the pin out of the hole.

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The design seems very similar to ours. Maybe you could of used something like grease to ease the friction on the pin and the wood. If you added some grease then It would definitely slide easier but might not solve the problem.

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We tried grease, the weight and friction acting against us was still too much. If I did my math right still about 450 kg

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