Many moons ago, like maybe 40, I gathered some parts to add a vacuum dust and chip collector to my home made overhead CNC router I named the HB2. As the saying goes, the road to hades is paved with good intentions. Texas may be hot enough to qualify in the summer, but I don't think I made it to the real hades. But in any case I have repented from my laziness and have completed the chip collector project. A Shop Fox dust collector was the immediate first purchase.
What put me off for such a time was how to make the collector hood that is installed on the spindle. You can see I use a Taig spindle. It's wonderful for my purposes and very quite. (But that is another story.) I thought of dozens of variations but really couldn't decide on any. Once I realized and convinced myself the hood didn't have to be 100% efficient at gathering all the chips, My options became more obtainable. My function now Is to get the fine dust and if some of the heavy chips escape, it is no big deal.
I have tested the cowboy boot you see in the pictures and it does work as expected. I have not yet carved a big project using it. I was trying to figure a fancy mounting bracket but then the K.I.S.S. principal kicked me somewhere (in the head) with the boot. That is a screw clamp (8") that is extremely effective at holding the boot in place. Also easy to remove.
The boot is a cut down 45 degree elbow. I epoxied a thin plywood plate on the bottom to ensure the suction would be closer to the spindle. You can see the plate has been slightly radiused back to keep the opening a reasonable size. If you haven't guessed the pipe and fittings are all two inch DWV schedule 40. The flex hose is listed as 2 1/2" which I believe is the OD. Plumbing pipe is ID.
The hose is clamped to the 2" pipe except at the boot. That is because I want to be able to pull the tubing off the boot and vacuum the top of the HB2 table surface. I have a short piece of extra 2" PVC I can stick in the tubing so I can vacuum into the far corners of the table. It is wonderful to think creatively.
I purchased a Shop Fox dust and sawdust collector I reported on elsewhere. It is low noise and can run for hours with no strain. I show the four to two inch adapter. This is a significant reduction of hose area and it does reduce the air volume of the Shop Fox. This does not make the Shop Fox work harder, it actually works easier because it is moving less air. It's termed FAN LAWS or Affinity Laws and anyone who thinks differently can Google the term. Not worth the effort to say more here.
I experimented with several options on how to route the hose. What is show here is the best of them all. The rigid pipe has less resistance than the hose so it is a good choice. The elbows are long sweep. This is very similar to a residential central vacuum system. I discovered the down connection had to be farther toward the front of the machine than the center of the working table space as the hose will get hung on the X axis stepper if it is farther back than seen here. Yes, there was a bit of trial and uh... Error in the design and construction.
The wood part is a 2 x6 cut (ripped) down to a 4.25" width. A standard 2x4 stud is too narrow for the clamps. I used some of the ripped off side material for the clamp stand risers. The flanges on the elbows prevent direct clamping to the main board. The plastic Clamps are 2 inch Clamps for electrical entrance conduit. Available at Lowes, five in a package and low cost.
Anyone interested in doing this can study the many pictures I have provided. It was an easy project and now I will literally breathe a lot easier and cleaner when 3D carving with the HB2.