This is my version of a dust manifold I saw in an old issue of ShopNotes from years ago. I don't have the exact issue, so I built this from scratch from memory.

It is for a 4" dust port collection system, but it should easy to modify for a 2.5" dust collection system (or any other variant).

I currently have two branches in my system. The design of my system is setup for the two walls in my shop and allows me to maximize flow by having two main branches. Each of the branches has 2-3 dust producing machines on them that are controled by off-the-shelf blast gates (Powertec brand. As an aside, I'm very unhappy with the quality of these gates. The door just flies off if you pull too hard. I ay redesign them in the future).

You could avoid blast gates and extend this system to more port, but I found it would lead to too much piping throughout the shop. And, adding a third port may change the overall design since I take advantage of the hard stops at the ends of the bracket to align the holes. I imagine you could expand this beyond 2 ports with some sort of clever alignment system or magnets.

Use the pictures for an explanation of how to build this - It takes a bit of glue to make it all work. And, screws to mount to wall. Or, in my case, a French cleat on my concrete wall.

• “Bracket Left” and “Out Left” are printed in purple & glued together
• “Bracket Right" and "Out Right” are printed in gold & glued together
• “In Port” is printed in black. It's important that you slide in that in port before you attach the bracket to the wall. The in port slides in a groove on the bracket and slightly overhangs each bracket to make sure it never gets caught up when sliding.

Enjoy. Let me know how it works out for you. I'm sure it could be better, but it's working for me right now.