|
I think it has to do with the somewhat and ironically rare concept of "compression". Most people are familiar with computer file compression, which takes a file that is one size and makes it smaller. Solid objects can be compressed as well. Technically they all have a constant of compression, that represents how much force is required to compress the object a certain amount. A sponge is very easy to compress, as is foam. A car tire rubber is a medium compression material, and I think sugar is made from beets compressed in a cylinder with a piston and a screw or other gearing mechanism to acheive huge amounts of force in a tightly contained metal container that gets smaller and squishes shut to compress arbitrary things. A simple compression chamber can be made from a tin can and a clamp, especially a heavy duty can. Note that the lid will fail quickly on a tin can, then the sides will blow out eventually if you get a heavy duty lid and wedge it in there. Note that metal will compress, however its compression constant is so high and it's so hard to compress metal (you need a supercollider) that if you used the above design with an inelastic material as the crosspiece, for example a metal crosspiece, and also an inelastic material as the rod (carbon fiber is less elastic than CPVC, but more elastic than metal), so if you used a thick metal tube with a taper and a crosspiece with a straight hole, it would seat down but slide up easily due to the taper, and rattle a little at the top. The gap could be filled with weld (melted metal) or glue, but otherwise there would be very little strength holding it down from being pushed up, but if it's pushed down then the tapered shaft snags in the bottom hole, which could blow out the hole with enough force but still should be pretty solid. Sideways would be the strength of the shaft, and would be the strongest direction. Since CPVC is pretty elastic compared to a human with a mallet, you can literally squish it on there like it's a sponge. However since it's a bit harder than a sponge, it stays in place pretty good and friction wedges it on there, along with the spring-like properties of compressed materials, thus forming a pretty strong joint potentially, about as strong as the CPVC?
|
