Recent content by teamtom

The pulley is bolted to the face of the beam, so it is not in the center, so it does pull rather than compress. Thanks for pointing that out. Tom

I hate to be a bother but if it is standing on end, what section modulus do I want? BTW, I did want to try for an I beam first if possible.

Exactly! Thank you very much. No offense but could I at least get some help for those "simple" calculations. I don't mind doing the searching but I have no idea what to look for. Thank you again, Tom I have E as 10,000,000? depending on the alloy... Is L in inches?

I (hopefully) don't need any help with getting the pumpkins out, I need help with an aluminum beam's strength in order to cock the machine. The old way of cocking the machine was to pull down on the throwing arm and the weighty end went up. The problem is, you have to build a very strong (read...

The beam is 18' long and starts out parallel to the ground and it is hinged at the end closest to the weight, the hinge is 1" steel rod captured in pillow block bearings. Essentially the cable goes from the crank (or in my case electric hoist) that is mounted to the base, to the base of the...

That reply is exactly why I was hesitant to post here.

I built a catapult (trebuchet actually) last year for the "Punkin Chunkin" where you throw pumpkins for max distance. This year I am planning on a slightly larger one and need some advice on aluminum. We basically use a primitve crane idea to lift the weight up rather than using a hoist or...