I think that you're doin' a number up a rope by trying to use a high velocity/low cfm vac for that set up. You will loose vacuum performance. Just my thoughts.

 

Bill,

Thanks for the response - anything you can suggest instead? My impression is a traditional dust collector won't work well for hand held power tools given the low suction of those units.

 

Forty feet of 2.5" PVC should be no problem for a shopvac. At 100CFM (about the limit of a shopvac) that length has less than 3" static pressure loss. This is nothing compared to the 60 to 100" of pressure generated by a shopvac. Note that flex hose has more than three times the pressure loss of the same size PVC so 30' of PVC loses no more than 10' of regular vac hose.

A number of years ago I used a shopvac for the overhead dust collection on my table saw. I plumbed it with about 15' of 2" PVC. It worked very well. I do recommend the 2.5" though because it has one third the pressure drop of 2".

Also, you should probably look at electrical conduit instead of plumbing pipe. The electrical 90s are a nice long sweep, which is desirable. As a bonus, it also costs less.

 

I have a narrow shop and hate having to deal with a shop vac that is constantly in the way.
I use a ducted central vac, that is rated at 130cfm and runs through a dust deputy. It has 2 separate runs one is 22ft long with 3 4ft drops the other is 20ft with no drops. I use this system for my miter saw, router table, oscillating sander, drill press, hand sanding, dominos and shop and garage cleanup. It is one of the best shop decisions I have made. The vac is rated for a 3600 sqft house and has more than enough suction. It has a hepa filter and I can exhaust it outside (I haven't found a need for that yet). It came with a 30ft hose that I use for my with my portable tools and cleanup. I bought mine new but I see them listed on CL all the time. The 2" ducting is proprietary to central vacs but is cheap and available online and through dealers. I bought the blast gates at Rocklers. With the dust deputy I haven't had to change the filter in over 4 years.

 

I do not think you need to worry to much about the tubing lenght.
It can be quite long as long as you have a good motor in there.
I would think that the cyclone you already have will be good enough.

If you start by adding the tubing and move your current shopvac and dust dep system to one part of the garage (or maybe in a smal housing outside your garage) then you can test it out without any investment other then some tubing and a bit of work.

You may always upgrade your vac and cyclone at a later time with very little effort.

The only thing you should be sure of is that you will continue to use only hand tools and not will need to change to a bigger system that requires other tubing (like 4" or 5" tubes).

BTW: I really like Bob5103's solution, but you might try to avoid the sharpes 90deg angels and use two 45deg instead - always think about how the air will flow and try to make as few obsticles as possible.

 

Guys, this is great. Thank you guys so much for sense-checking me.

Dave, thanks for estimating the pressure drop, you are right, that sounds minimal. Bob, thanks so much for pics of your setup, that was basically the exact type of setup I was considering.

I'm going to run some tubing and then try it with my current POS shopvac and cyclone (which I love) and then look into changing the shopvac to either a solid central/garage vac or a Festool dust extractor if I decide I want flexibility to take it somewhere else.