Replies

1. 
   saschafer | May 09, 2008 05:02am | #1

   It's a little tricky to set things up so that both are running efficiently and pulling their share of the load, but it can be done. You want to operate them in parallel, and equalize the runs to them as much as possible.

   -Steve

    

1. 
   nazard | May 09, 2008 08:06am | #2

   Steve,

   Several questions along the same subject:

   1. What about a small (1 hp ??) booster in series on a long run to one machine?

   2. What amount of increase in CFM and static pressure could you expect by combining two DC units in parallel?

   3. Wouldn't you be better off upgrading to a larger DC system rather than combining two DC units?

   Best as always!

   -Jerry

1. 
   flairwoodworks | May 09, 2008 09:00am | #3

   Jerry,

   Kind of a different topic, but I operate a 1HP dust collector with a long run of duct (too long).  To help, I've added a Steel City Mini Dust collector along the line (closer towards the dust-creating tool) to help increase CFM.  It seems to work quite well.Chris @ http://www.flairwoodwork.spaces.live.com

    - Success is not the key to happines.  Happiness is the key to success.  If you love what you are doing, you will be successful. - Albert Schweitzer

1. 
   nazard | May 09, 2008 10:31am | #4

   Chris,

   That's exactly what I may end up doing.  The other option is starting over with a cyclone.  Finding the room in my basement shop is a major issue.

   Best!

   -Jerry

2. 
   saschafer | May 09, 2008 04:01pm | #5

   "What about a small (1 hp ??) booster in series on a long run to one machine?"

   In principle it should help, but I think you'd have to work out the details on a case-by-case basis to figure out how much; there are just too many variables. What should definitely help is a booster right at each machine (like some planers, combo machines, etc. already have). But even then you have to ensure that the booster has a big enough "throat" that it doesn't act as a bottleneck.

   "What amount of increase in CFM and static pressure could you expect by combining two DC units in parallel?"

   You'd have twice the CFM at the same static pressure, assuming you did a good job of plumbing. I would only try it with two identical systems; otherwise, it's too hard to balance them.

   "Wouldn't you be better off upgrading to a larger DC system rather than combining two DC units?"

   All else being equal, the cost and performance of a system with twice the capacity is almost always going to be better than that of two smaller units. But if you already have a smaller unit, then the incremental cost of an additional smaller one might be favorable.

   -Steve

    

1. 
   nazard | May 10, 2008 12:49am | #6

   Steve,

   First off, thanks for your help.  I do appreciate it greatly!

   What if I were to connect with a "Y" two 1 hp DC units, with equal short runs of duct, to a cyclone separator, and the separator to the main DC duct run? I would then be able to run only one unit for low suction devices like the RAS and router table, and both units for TS, planer, etc.  This would be a cheap setup for now and could be broken down for other uses at a later date.

   I am at this moment thinking that it seems too good of an idea to be true.  Any thoughts?

   -Jerry

1. 
   saschafer | May 12, 2008 02:02am | #7

   Well, that's exactly the kind of thing I was talking about. Will it work? Probably. Will it work well? Possibly, but don't hold your breath. Dust collection systems require quite a bit of "tuning" for optimal performance. Be prepared to do some fiddling to get it right.

   -Steve

    

2. 
   nazard | May 12, 2008 03:05am | #10

   Steve,

   Well, since it's not a bunch of $$$ I'm giving it a try.  I'll pick up some 6" duct and fittings at my local hardware store for the main run (at the moment it is 5").  I am going to run a 4" to my overhead TS guard - that should be a major improvement over the 2 1/4 shopvac.  We'll see how it works. 

   I ran across some additional info on Sawmill Creek.  This post by Bill Pentz is encouraging:

   "If you were to dig back into the Badger Pond Archives, you would see that quite a few tried running two blower systems. Those that put them in series found out what happens when you try to move too much air with a blower. The motors badly overheat and fail. Those who ran a pair in parallel found they worked well, in fact in many instances much better than those who ran a single motor with twice the horsepower driving a much bigger impeller. Jim Halbert who taught me much of what I know about dust collection is still running a two blower system.I believe that you would be just fine running the two collector inlets into your ducting provided you go with at least 6" interior diameter ducting."I should have everything up and running in a week or so and I will let you know.  Thanks again for your help.

    

   Best!

    

   -Jerry

3. 
   nazard | May 22, 2008 02:26am | #13

   OK Steve,

   I've got the dual DC setup far enough along to give it a test fire.  At this point, I have run 5" lines because that's what I had the most of just setting around the shop.  I have not done anything yet about a separator.  The overhead guard for the tablesaw is not back in place.  The AC for the 2nd unit is all in place, but not tied in at the panel.  BUT... when I power it up, the system sucks! (that offensive word again...).  I'm getting 8" static which is what one unit alone draws, but definitely a major increase in CFM: sawdust at the bottom of the tablesaw cabinet immediately disappeared.

   I'm going to finish tieing everything up this weekend and live with it for awhile.  A future change might be to increase the plenum between the two machines to 6" and perhaps add a separator.

   At the moment, I can consider the project a success, and begin plotting on how to lure the family cat downstairs.... Thank you so much for your help.

   Best!

   -Jerry

4. 
   saschafer | May 22, 2008 04:07am | #15

   Sounds good. I think you'll find that you get even better performance with a 6" duct.

   -Steve

    

5. 
   Tinkerer3 | May 12, 2008 03:01am | #9

   In order to run the one blower, in order to save power, you would need to gate the inactive blower.  Otherwise a good part of the rushing air would be wasted by recycling back through the inactive blower.  After using the system for a while, you would probably just use the two blowers together all the time.

6. 
   nazard | May 12, 2008 03:14am | #11

   Tink,

   Yep.  But think how funny the bottom collection bag on the unused DC would look trying to crawl back into the machine...!

   Anyway, I'll let you know how this new setup works.

   Best!

   -Jerry

7. 
   Tinkerer3 | May 12, 2008 04:21am | #12

   For entertainment, it may be worth the try.  Ha, Ha.

8. 
   nazard | May 22, 2008 02:30am | #14

   Tink,

   You were so right... and it's SOOOO funny!  When you crank on just one machine, the collection bag on the second machine does a wicked prune imitation.

   Best!!

   -Jerry

2. 
   Tinkerer3 | May 12, 2008 02:55am | #8

   Per his post, I think he already has the two 1.5 HP units.  His only added cost is that of hooking them up and the extra elect to run both of them at the same time.  I think he would get a big boost.