Replies

1. 
   davidbrum | Dec 17, 2008 06:00am | #1

   Hi

   I have an identical tool setup, serviced by a Jet 1.5 hp DC. I plumbed everything with 6" pvc and get all the chips from my planer. I don't run two machines at once though.

   You will get a bunch more airflow from 6" ducting, for sure. You'd have to refer to Bill P's site for the figure, but I believe it's more than double that of 4". It works even better if you can install a 6" port on your cab saw.

   You might be surprised at how much better your DC will work with the bigger ducting. I figured I'd install it until I got around to buying a cyclone. It works so well that the cyclone moved way down the "want" list.

   david b

   Time flies like an arrow. Fruit flies like a banana.

   David B

2. 
   nazard | Dec 17, 2008 02:03pm | #2

   Ditto what David B. said.  6" line.

3. 
   Jfrostjr | Dec 17, 2008 04:49pm | #3

   For a rough estimate of duct capacity, "square" the diameter.

   6 x 6 + 36; 4 x 4 + 16;

   Nuff said.

   Frosty

   "I sometimes think we consider the good fortune of the early bird and overlook the bad fortune of the early worm." FDR - 1922

1. 
   nazard | Dec 17, 2008 05:44pm | #4

   Frosty,

   Quick and dirty.  Pie are square.  I like that!

   -Jerry

1. 
   joinerswork | Dec 18, 2008 01:09am | #5

   naz,

   Pie are round.  Cornpone are square.

   Ray

1. 
   nazard | Dec 18, 2008 01:24am | #6

   Ray,

   Please pass the butter!  Pie ARE round.  Cornpone BE tasty! 

   -Jerry

4. 
   SantaFeTom | Dec 18, 2008 01:56am | #7

   You can try moving the biggest chip producers as close to the DC as possible but I have found from personal, expensive experience that 4" ducts won't do the job. The fact that it is flex tubing makes it even worse. When I got a 20" planer, I had to replace all my 4" rigid plastic ducts with 6". I went with metal.  Even with the planer within 10' of the DC. the 4" ducts couldn't handle it. 6" all the way to the tools is the best, even if it means modifying the tool to take 6" pipe. Second best is 6" as far as you can get it and then 4" the rest. That could even be a problem because the chips coming from the 4" duct might settle in the 6" because the 4" might not allow enough air flow to keep them moving. Now if I could only find a use for a closet full of slightly used 4" plastic ducting.

5. 
   Wingdoctor | Dec 18, 2008 03:30am | #8

   As others say a 6" pipe will help a lot. I also notice your reference to "T's". T connectors should not be used for the branches as they restrict the airflow too much. The drop for the branches should be a radiused turn from the tool going toward the collector. These are available in a couple of different radii and the bigger the radius the better it will work.

   Bruce

   "A man's got to know his limitations." Dirty Harry Calahan
1. 
   morrisericd | Dec 18, 2008 04:52am | #9

   Wow, thanks for all of the help. I've started the process of planning out for the ductwork and have gained a lot of insight from Bill's site. I think all and all, I'd rather go with a commercial metal duct system, but am leaning towards PVC for cost reasons. I will be purchasing Lee Valley's through gates as recommended by Bill. I've always been frustrated with my gates and their inability to close all of the way when clogged with dust.

1. 
   Wingdoctor | Dec 19, 2008 12:24am | #11

   You might want to check out these blastgates. They close all the way all the time, are all metal, and very cheap. I use them in 4", 5", and 6" in my system.

   Bruce"A man's got to know his limitations." Dirty Harry Calahan

2. 
   Y1RET | Dec 22, 2008 11:51pm | #12

   Bruce

   <!----><!----> <!---->

   Just to pile on, I have the same <!----><!----><!---->Grizzly<!----> <!---->DC<!----><!---->, ten year old, 2 HP, two-bagger. The original user guide rated it at 1100 CFM. I think the version they are selling now is rated higher, however, they look the same. I added a 16 inch planner and the only way the DC would keep up is to pipe it directly to the planner with no more than 4 ft of four inch flex hose with no bends.  I realize the 4-inch flex is not a good solution. Perhaps smooth metal duct will help.

   <!----> <!---->

   I ended up going to a bigger DC and metal duct work. I also recommend http://www.blastgateco.com/ for blast gates and duct bends and joints. They were less expensive with thicker gauge metal than anyone else I could find. They custom made several y and bends for me that reduced in size so I didn’t have to buy additional reducers. One of the joints was damaged in shipping and they shipped another one to me with no issues at all. Good prices and customer service and they stand behind there product. I did end up buying the straight duct locally from an HVAC supply company because of the shipping cost and I could get 13 ft long sections instead of the five foot sections available online.

   <!----> <!---->

   Bob T.

3. 
   Buster2000 | Dec 23, 2008 01:08am | #13

   I will be purchasing Lee Valley's through gates as recommended by Bill.

   Just a note on these gates.  They don't always fit in all situations.  They need clearance on both sides of the gate (a 'normal' gate only needs it on one side).  The clearance is such that it can not be attached to a 6x6x6 wye.  Along the walls this was a huge problem.  There are ways around it, however I think in most problem cases you'd be better off with a 'normal' gate.  I used these gates in the middle of runs, and normal gates when there was a hose being connected.

6. 
   WillGeorge | Dec 18, 2008 07:08pm | #10

   I have the normal tools: 15" planer, cabinet saw, 8" jointer,   LOL   LOL...

   Wee bit wider than this 'normal' shop! Fell off of my chair laughing!

7. 
   Buster2000 | Dec 23, 2008 01:28am | #14

   So, first things first should I replace my main trunk line with 6 inch metal and then reduce it at the machines?

   If you do this you need to also replace the 4" flex hose connector.  Second don't reduce.  You need to run 6" all the way to the machine, any reduction will restrict the airflow.  You can split the run up, but the cross sectional area should roughly equal the area of the 6" hose.  For instance I run 6" up to my table saw (28.3 sq in.), it is then split into 4" for above, 2.5" for the blade shroud and 4" for below (12.6sqin + 4.9sqin + 12.6sqin = 30.1 sq in).

   I  know I should have used 6" ducting from the start and will do that regardless, but I'm not sure that will solve my problem.

   No, it may only lead to plugging.  Your 2HP system may not be large enough to maintain airflow in a 6" duct.  You need something like 3000FPM to keep the larger chips suspended.  You need to move at least 500CFM, which given a 2HP collector is probably is not possible.  (Remember the 1100 CFM or 1500CFM is the rate given with no or very little static pressure.)

   As if I haven't asked enough questions, if I were to go to metal ducting, should I go all the way and use Nordfab? It's almost cost prohibitive, but it seems like just about everyone here that uses it, loves it.

   I ended up using 6" 26 Ga HVAC pipe.  The norfab stuff looked great, but yes very expensive.  If I were more than a hobbyiest I'd consider it, but this is just for fun.  I paid $1.60/foot for the 26Ga stuff...