I built another dust collector over the weekend, using 3" pipes using an inverted bucket. Air outlet through the bottom, baffle held in place with a couple screws through the side, hole in the side of the bucket for the intake.
Everything fitted nicely together, this was the perfect simple setup (pictures to follow), but then the whole bucket fell over while it was running, :(.
Then my leafblower died, not sure what is wrong with it, it does not seem to be getting any fuel. :(
In any case, I bought a new electric leafblower, most powerful I could get at the local hardware store, I tried it in the pull setup (leafblower on the outlet) on my first lid, but the vacuum it created would collapse the bucket. The problem with this leafblower was that the outlet was square, not very useable for a push setup.
Then I found the gas powered leafblower that was the perfect fit at another hardware store, it is little bit more powerful than my old one.
The outlet (blowing) fit the 2"1/2 vacuum fittings nicely so I can connect a vacuum hose directly from the leafblower to the inlet of the dust collector bucket.
A couple of quick tests today and some small improvements look like a reliable working setup.
The only problem is that the leaf stems tend to clog up the pipes if I suck up too many at the same time.