Welcome to EE..
I would contact an organization that manufactures or sells Urethane Rollers. Other sources - http://www.engineersedge.com/plastic_design_menu.shtml
I am not sure if I am posting on the right thread so please advise if I am in the wrong place.
My wife and I are working on designing a foam roller similar to the one attached. The one attached is basically 4" pvc tube with foam on the outside.
We are trying to create one that is 26in long and is able to detach into two pieces 18in and 8in in length.
Our initial idea was to have both pieces connect by an individual fully threaded piece of pvc, but that would require the tubes to be threaded. I kow pvc is not meant to be threaded and we need it to be able to withstand at 300-400lbs of weight when both pieces are connected
the goal is to do this without having something protruding out of either of the separate pieces when they are disconnected. Any suggestions?
It is hard to connect two parts together securely without having anything protruding from them. It's kind of necessary for a temporary joint, otherwise you are asking two flat faces to hold on to each other without anything to grip on. You are right that PVC would not hold a joint very securely, so you would have to fashion some sort of insert, metal or plastic, to go in either end that would be able to interact with each other.
A thread could work, or some kind of locking mechanism, such as that on a bayonet lightbulb, could work. It's also important to think about the kinds of forces that would be put on the two parts - could they accidentally unscrew during use?
would you be able to sue some sort of hot glue to bond the 2 units then heat again to release them when needed? not sure what the application is..