charliemachine
Mechanical
Hi folks I have a problem that I'm second guessing myself on too much for something that's probably very simple. I have to fasten dozens of counterbored 30mm square aluminum extrusion, each about 30" long, to a wall which is a sandwich of plywood and drwyall (long story). I'm planning to fasten them with "snap toggle" anchors, which means the 1/4-20 bolt will be 3.5" long. I will be putting about 70lb onto the top of the extrusion, 3/4" off the wall. My question is, if I'm concerned about the bolt strength do I treat this as a shear problem with a derated capacity (and if so, derated how much?), or as a simple force on a cantilever beam problem? That doesn't seem right because the threaded toggle isn't firmly fixed in place. Alternatively, is there a much more suitable fastening method for this kind of situation? Thanks!
