dust pipe questions 6 or 5

[Jason Thaxton]

I have the 2hp super dust gorrilla. From what I have read I should have 6 inch pipe run to each machine. On oneida's website it says to run 5 inch. I am wondering if I should run 6 inch pipe to each machine or should I go 5 inch. This is for a 30x30 shop with the longest run being around 27 feet.

[Steven Wilson]

I have a 2HP Oneida Commercial which I believe is very similar to yours. I run 7" from the collector through the first turns to get it to the ceiling. From there I split to two 6" mains which service most of my machines. One branch services a bandsaw, drill press, and router table. The termination is a 6x6x5 wye (first 5" blast gate) and a 6x5x5 wye (2nd and 3rd 5" blast gate). The second 6" runs about 12' along the ceiling to a 6x6x5 wye. The 6" take off turns down from the ceiling and terminates in a 6x5x5 wye (two 5" blast gates). This services a European combination machine, Performax sander, Griz OSS, and horizontal belt sander. From the 6x6x5 wye on the ceiling I run another 12' or so of 5" which then turns down from the ceiling and services a dust hood for my lathe. The last run is my longest run and the 5" is sufficient. I wouldn't want a CFM hog on that last run but for collecting sanding dust from a lathe it's good enough. My CFM hog is the Euro combo machine and it's center is about 10' from the DC which is around 18' of pipe/hose. Since the DC hoods are fairly decent in the combo the 5" flex hose services the machine fairly well. If my combo were further from my DC I would have opted for a larger DC.

So is the 2HP dust gorrilla sufficient for a 30x30 shop? It might be depending on your machine layout, but it is on the small side. As for pipe I would run 6" and then you can terminate into 5" or 6" and run appropriate flex to the hoods of your machines.

[Cary Swoveland]

Here are a few suggestions.

1. 5" is fine for most machines, so I don't think I'd advise 6" for everything. I have 6" for my table saw and short 5" runs from a 6" main for everything else. 6" would be appropriate for some other machines, such as a 20"+ planer or drum sander.

2. You'll probably end up rearranging your shop more than once, so provide as much flexibility as you can with the DC design.

3. Do not run any pipes less than 5". For machines with 4" dust ports, install a 5"->4" reducer on the machine's dust port.

4. Use as little flex hose as possible. It generates much more static pressure per foot than does (smooth) rigid pipe of the same size. In some cases you might run rigid pipe from a machine's dust port for a distance before connecting flex hose. I did that with my band saw and table saw.

5. If using galvanized pipe, make connections with screws or rivits and wrap with aluminum tape to seal. You'll be changing parts of your DC system in future, and it's a mess if you've used silicone or caulking. Moreover, the aluminum tape works fine for sealing.

6. Give careful thought to the locations of blast gates. Avoid locations that make it ackward to open and close them. Most of mine are 3' or 4' off the floor, within easy reach.

Cary