I know it's ugly compared to some of the other builds on this forum, but I'm really happy with this separator's performance. However, the metal trash can would make a loud bang whenever I blocked the inlet. Since I'm using it as a vacuum, this happened quite often. I nearly jumped out of my skin the first time it happened. I made a simple common sense mod that took care of the problem. I put an OSB ring half way down inside the can. Right now it is just a press fit. If it needs a more substantial attachment, I'll use some screws or something to anchor it. I know its not much of a mod, and it may have been done before, but I hope it is useful for someone.
As long as your stiffener ring remains loose, emptying the can is not much of a problem. However, if you have to attach it with screws I suspect you will be cursing it every time you empty the can.
So far it is holding. I built a new top hat today and used the first one to clean up.