Dust collection pipes question

[George Oak]

I have a Delta 1.75 HP dust collector that I was thinking of upgrading to a cyclone. However, due to other tool purchase priorities, and the cost of a new cyclone with pipes (I got quotes in the $2,600 range for my shop) I decided to stick with the Delta for at least another year.

The performance of this unit is absolutely adequate using the short runs of flexible plastc 4" hose I connect it to various tools (table saw, bandsaw, jointer, planer).

However, I just finished my miter saw bench, and I need to run a dust collection connection to this very badly (my SCMS being the dustiest tool in the shop). For the saw I set up a two-tier dust collection approach: I am connecting a 2.5" flexible hose to the dust port of the saw, and have installed an open hood behind and underneath the saw to catch the additional dust and debris. This latter 4" pipe comes up from underneath the bench, and ties in with a Y connection and reducer to the 2.5" dust port hose.

I need a total run of 25' of pipe to get me from the dust collector to the miter bench. I have considered two options:

1) Use rigid PVC pipe (hung from the joists), including straight members and large-radius 90-degree sweeps to span most of the distance. Run grounded copper wire inside to avoid static issues. The benefit of this is that the pipe is smooth and should help maintain airflow. The downside of this is that I am not sure if I can find the proper diameter pipe that will work with the standard 4" flexible dust hose for making the connections at either end of the pipe.

2) Use standard 4" spiral-wire-reinforced dust hose all the way. The benefit of this would be that fitting the various connectors to the hose is no big deal, as these are already designed to fit. However, I worry that the spiral ridged hose will reduce the airflow too much, and the dust and debris won't get lifted to ceiling height and carried across the span I need.

So what do you think, which is the way to go? Any optinions appreciated.

[Ken Harrod]

If you intend to upgrade in the near future, then why not use the piping you would be using with the new system? 6" piping is the most common recommended size piping to all tools. Run it with 6" PVC, and this would then be able to be used when you upgrade to the newer system. More money now (than 4") but cheaper in the long run.

Oh, and don't glue the sections of PVC together, so you can reconfigure it in the future.

[Jerry Booher]

I am just finishing hanging my ductwork for my Oneida 2.5 hp cyclone. For a 29x29 shop I bought 50' of 7" and 20' of 6" 24 gauge spiral duct, 5 wyes, lots of connectors and miscellaneous. All of the sheet metal cost $363 from a HVAC distributor. Hoses are about $130.

I can't use PVC because PVC and dry humidity in Arizona would be like getting a shock from a heart defibrillator every time I touch it!

Jerry

[Denny Rice]

You know if you don't mind woking a little, you can use that 1.75 HP DC and make a cyclone. Dizzy use to have a pretty cool webpage where the took a DC apart used the major parts of the DC and added a cyclone chamber. I know there are plans on the web for them, and there are cyclones for sale on ebay. They come in a 4 or 6" dia. outlet and run about 150.00-200.00 dollars. Might get you buy until you can come up with the cash. I think if you searh Dizzy on SMC search, there is some stuff here too.

[jim gossage]

i have a bunch of standard 4" PVC from Borg in my system. the standard elbow, Y, blast gates, and couplers fit pretty well into the PVC. sometimes its a snug fit, and other times I run 1 wrap of duct tape around the end of the fitting to make it fit snug in the PVC. one consideration with adding 6" pipe to your current system is the CFM of your dust collector. if the CFM are not great enough, there may not be enough suction to maintain adequate dust and chip velocity through the larger pipe. its probably not a problem with your 1.75 HP model, but you should check to be safe.