Replies

1. 
   WayneL5 | Oct 16, 2004 12:43am | #1

   Electrical conduit uses elbows with much larger radii than the same size plumbing pipe.  In electrical terminology conduit elbows are called "sweeps".

   Galvanized steel duct would have larger radii than plastic pipe and you won't have a static electricity problem.

2. 
   Dave45 | Oct 16, 2004 04:31pm | #2

   I made my DC system with the plastic (ABS?) fittings (elbows, Tee's, and blast gates)connected to straight runs of 4" HVAC ducting.  I used self tapping sheet metal screws to tie it all together and taped all the joints with electrical tape to eliminate air inleakage.

   The whole contraption is mounted under my work bench/outfeed table with 4" flexible duct connecting to each machine plus a port for my bench top tools.  It's a bit of a pain to remember to open/close the appropriate blast gates, but it's not a big deal.  I have a remote switch for my collector which is worth its weight in gold.

   I also found that having the blast gates open in the downward direction virtually eliminates having to occasionally clean the sawdust out of the gate channels.  (One of the attached pictures shows one opening to the side, but that was changed a few months ago.)

   
3. 
   SCFrankland | Oct 17, 2004 05:28am | #3

   Check my website and go to the workshop page to see my DC network. I got most of my stuff from a reno job at the airport here. Maybe worth checking out a large scale job site.

   Scott C. Frankland

   Scott's WOODWORKING Website

   "He who has the most tools may not win the race of life but he will sure make his wife look like a good catch when she goes to move on."

1. 
   Dave45 | Oct 17, 2004 05:43pm | #4

   Nice shop, Scott.  Overhead isn't an option for me since I'm in a garage and the rollup door takes up most of the ceiling space.  I have to be real creative with keeping things low - lol

4. 
   nikkiwood | Oct 17, 2004 06:26pm | #5

   If you are using standard schedule 40 4" PVC, you will find two different elbows -- one is a standard tight 90 degrees, and the other is a longer, more sweeping 90 (I think it is called a "street" 90). This stuff is sold in any home center.

   Are you sure, though, you want to use this kind of pipe for your DC system? Static electricity can be a real problem, and there are other alternatives, which are only slightly more expensive.

1. 
   nicobie | Oct 17, 2004 08:56pm | #6

   Hi nikkiwood,

   I've been using plastic ducting for years and have never been zapped. All shop and home vaccumms come with un-grounded plastic hoses and I've never heard of any problems from them either.

   Maybe it's a humididy thing? I don't know. All I know is that S&D PVC ducting works fine for me.Government's view of the economy could be summed up in a few short phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it. Ronald Reagan, August 15, 1986

2. 
   Mackwood | Oct 20, 2004 02:54am | #12

   I'm running a 3 HP unit with 4" PVC piping as well.  I did go to the trouble of running a ground wire along all the plumbing and to all the machines.  I've never had any sort of static buildup or problem.  Personally, I think the wire was a waste of time but the wire was free and I'm not taking it off! LOL

   Back several years ago the "word on the street" was that there was an explosion hazard with DC systems with plastic piping.  Recently however I've read that this applies only to much larger systems than most of us are willing to even talk about (7 HP and larger).

   My system is very un-tech but it works and I have never had a problem with it zapping me!

   The PVC pipe is cheap, easy to repair and very tough.  Most of the metal piping I've seen is expensive and squashes pretty easily

   Regards,

   Mack"WISH IN ONE HAND, #### IN THE OTHER AND SEE WHICH FILLS UP FIRST"

5. 
   triplenet | Oct 18, 2004 02:50am | #7

   I have a Torit 2hp DC. I used snap HVAC duct with plumbing PVC for Y's so the radius is not so tight. I used the adjustable metal bends (can't think of the right term) for all drops. These are the ones that are segmented and straight when you buy them, but twisting the sections vary the angle.

   Screw it together with self taping sheet metal screws and tape all joints with METAL duct tape, not the cheap junk, and hang it with plumbers' strap. Buy metal blast gates. It all works great. Best idea is to lay out what you want and then go to the supply house (Lowes, HD or ?) so you can see and play with the angles. It makes it much easier.

   Also, get the remote switch! I think it's call Long Ranger, it's a godsend.

   Good luck,

   Bob

6. 
   RandMCapozzi | Oct 18, 2004 02:53pm | #8

   If you are unable to locate a larger radius 90 you might be able to use two 45s with a short section of straight pipe between them.

   --Rob

7. 
   mbiker1999 | Oct 18, 2004 08:07pm | #9

   I used thin walled PVC piping and 45 degree elbows for my system.  The price is right and it works great.  As one other poster suggested use 2 45's and a small section of straight pipe for your 90's.  Also I've used flexible pipe for some 90's.  It allows you to sweep the turn as wide as you like.

   Good Luck!

8. 
   EvilTwin | Oct 18, 2004 09:08pm | #10

   Lowes sells the 4" and 6" thinwall pvc tubing and fittings.  But before you go off and start designing, what size dust collector are you planning on putting in?  If  it is 1.5hp or greater, you really need to consider going with 6" tubing (5" in metal) since 4" is too restrictive for the amount of air that machine can move.  The 4" stuff is relatively cheap, the 6" fittings and the pipe cost a bit more than the 4" and there are no commercially made blast gates that I can find for 6".  Still, there are benefits from going to the larger size that you should consider. 

1. 
   mbiker1999 | Oct 19, 2004 03:18am | #11

   I have the 1.5 HP delta DC. Since the DC has 2 4" ports off of it, I ran 2 4" runs in my shop from each of the ports. I have one overhead and one that runs along the wall on one side of the shop to pick up a few machines there. It works great for me. The airflow at the farthest end of the run is very good. I considered running a single 6" main duct down the middle of the shop but the 2 4" runs were a little easier and probably cheaper too.

   best,

2. 
   RouterFin | Nov 08, 2010 11:59pm | #13

   2HP Dust Collector = 6 INCH PIPE

   Thanks for the Heads Up on the 6 Inch piping and Lowes ....Dumpo does not carry 6. It does make a differance, my Harbor 2 HP has a 5 " Inlet with a plastic Y fitting over it with 2 --- 4 inch inlets = 8 which you can use one or the other but not both without dropping the vac pressure....I am taking the Y off,and going 6inch. The Closest to 5 is 6inch

   without going smaller than 5, this way i can use 2 --- 2 1/2 inch hoses pluged into the 6inch and use them both at the same time and be MAXED out =5inches

   thanks again

   RouterFin

9. 
   oldfarmboy | Nov 09, 2010 10:27am | #14

   dust collection tubing

   I have a 3 HP Oneida system and have used 8-inch tubing as the mainlines.  One branch goes to 6-inch for the 20-inch planer and jointer.with 6-inch gates.  The other branch goes to everything else dividing into 5 and 4-inch branches to the bandsaw, table saw, radial arm saw and floor sweeps.   One segment is 2" for 6 feet for the router dovetail jig.  The larger tubing decreases the resistance and system works better.  The company haslarge bends,  larger gates and remote control.  Overall the system has worked well for 3 years.

   Sam,   Upstate NY