The 4'' PVC Elbow is anchored to the bottom with three right-angle braces, to prevent it from rotating. The Output pipe is held in place with GE Silicon II Household Glue (top side) and friction; very tight fit. The 45 degree coupling on the top has enough slight to allow it to rotate, but...
Thought you might like to see my latests project. I wanted to build a separator for my new Delta 50-760 1-1/2 HP Dust Collector -- a recent Gloat.
It really works good! Check out the nifty sawdust level window:
I was hoping I could make one similar to one of the separators in this...