Does size matter?

[toolmanlh]

Getting things together to setup my HF dust collection system. Will add the Wynn filter ut first I want to make a Thien lid for a trash can. Is there an advantage to the 31 gal over a 20 gal.?

[alan m]

depends on what your doing and how often.
if you are using it with a table saw, bandsaw, and sanders then smaller is fine.
if your using a planer thicknesser  then bigger is better.
but remember that you will have to dispose of a lot more dust in one go with the larger drum. that drum will be heavier and more awkward .

I use an oil drum sized barrel. is big and awkward but barely big enough when planning. iv often emptied it 4-5 times a day   from the thicknesser . then I mightnt empty it for a month

[retired2]

See my last post in the thread directly below this one.  It echoes many of Alan's comments. 

Getting waste into the drum is only half the battle.  Once it's there you need to get rid of it.  And if you need to transfer it to a plastic garbage bag as I do you certainly don't want to go bigger than 30 gal.  That size lets you transfer to heavy duty 33 gal bags.

The 20 gal certainly is the most convenient to empty, but it introduces a potential problem, i.e. a separator that is too small in diameter for 5" or 6" plumbing.

[toolmanlh]

Right now my plan is to go with all 4" piping. I like the idea of keeping it (the trash can) smaller just because of space constraints. I don't mind emptying it more often, I just don't want to wish later I had gone with the bigger circumference because the smaller one doesn't work as well. I plan to have my Grizzly 690 cabinet saw and 6" jointer connected very close to the collector with a line running over head and down to my 17" Grizzly Bandsaw with another Y off that to my shaper. Somewhere I will also include a connection for a portable planer  or other tools like disc sander/oscillating drum sander etc. that will be on wheels and moved in an out as needed. 

[Alan H]

Just for consideration, you may regret only going with 4" piping.  Based on my research it may not give you enough CFM.  The HF Collector is 5" at the impeller body, but many threads recommend enlarging that to 6" for better volume.

[retired2]

Right now my plan is to go with all 4" piping. I like the idea of keeping it (the trash can) smaller just because of space constraints. I don't mind emptying it more often, I just don't want to wish later I had gone with the bigger circumference because the smaller one doesn't work as well. I plan to have my Grizzly 690 cabinet saw and 6" jointer connected very close to the collector with a line running over head and down to my 17" Grizzly Bandsaw with another Y off that to my shaper. Somewhere I will also include a connection for a portable planer  or other tools like disc sander/oscillating drum sander etc. that will be on wheels and moved in an out as needed.

There is an article that has been linked here several times that argues that 5" plumbing is the sweet spot for 1-1/2 and 2 hp dust collection systems.  Unfortunately, stepping up from 4" to 5" or 6" increases the cost and difficulty of finding components readily.

From your description of your ultimate system, I predict you will regret building a 4" system.  The only thing more expensive than a 5" or 6" system, is building  4" system and then replacing it soon after.  If you have any hope of capturing fines from sanding tools or even fine saw dust, you need all the CFM's and SP your system can muster, and 4" plumbing has much higher friction losses than 5" or 6".

The longest run in my shop is about 30 feet of pipe.  I have 5" pipe and at the end of that run is either a band saw or a disk/belt sander.  I have a highly rated dust collector, arguably better than the HF without mods, and the performance at that distance is very marginal.

What everyone seems to ignore is that a separator inserts about a 35% (or more) frictional loss into your system.  That is 1/3 of your blowers performance lost before you even add the first foot of pipe, so you need to preserve every bit of what is left to insure reasonable performance. 

I ran my system for quite a while before I built my separator, so I know what kind of performance I was getting at the end of the 30 ft. run.  It was dramatically better than it is now.  Previously, the band saw never had a bit of sawdust escape, that is not the case with my separator installed.

[toolmanlh]

Thank you for the replies. I must admit I was trying to take the easy way out. Perhaps going with a 5 or 6" initial run that would pick up the table saw, jointer and portable planer and then reducing to 4" for the overhead run of 15' plus drop to the bandsaw, would serve me better. That would connect my most used tools. Adding the Wynn filter is definite. Still debating the Thien vs. Super Dust Deputy.