Dust collector

[kevin nee]

Does anyone have the Harbor Freighy 3 HP dust collector
I have a 25 to 30 foot run with a few elbows. any tips on PVC pipe size
Any help would be appreciated. Only running one machine at a time.
20 inch planner, double drum sander, table saw, band saw, and mitre saw.
2 HP Relleint doesn't do a good job with 4 inch pipe.

[Neil Brooks]

I'm pretty curious about the 3HP HF DC, too, since I run the 2HP, with a Wynn cartridge filter.

I hate to do it, but ... you may want to (brew a pot of coffee, and) take a look at Bill Pentz's (http://billpentz.com/woodworking/cyclone/index.cfm) site.

It's like the Smithsonian, for dust collection. You could run in, and learn a thing or two, or pack a suitcase, and stay for a week.

My gut tells me ... you should run straight pipe, and use a 5" or 6" diameter. As few bends as possible. As little flex hose as possible ... unless you've spent BIG bucks on truly "smooth-bore" hose.

I don't know your reliant, but ... have you tried switching to a cartridge filter ? Improved airflow AND filtration. When I put the Wynn 35 on mine ... big difference.

I also removed some flex hose ... yesterday ... and ... well .... here ;)

http://lh6.ggpht.com/_WVVYjLCNo2w/TSN8qzHPtII/AAAAAAAABeI/wYWXXh17kKw/s512/P1050066.JPG

http://lh5.ggpht.com/_WVVYjLCNo2w/TSOpG7D6n8I/AAAAAAAABeY/F82lH5vpEvw/s512/P1050068.JPG

I'm looking at swapping out my 28' of 4" flex hose for ... something -- either a combination of straight pipe and flex connectors or ... a true smooth-bore hose.

Allegedly, 1' of corrugated hose is like 1.5' of straight duct (PVC or galvy).

In other words ... you MAY be able to improve what you have, and make it better than the 3HP HF DC.

"May" :)

[david brum]

Hi Kevin

I have an older 3 hp DC which looks similar to the HF model. This is an old design which has been pretty much been made obsolete by newer cyclone designs which do a better job of separating fine dust before it gets into the filter.

These older designs have some good points though. Because there they are very efficient, they can pull a huge amount of air with a relatively small impeller. They are also fairly cheap to produce, since the tooling, etc is long since paid for. They also have a small footprint compared to a cyclone system.

The downside is that they are single stage dust collectors, which means they will let gobs of fine dust, etc into the filter or filter bag. I built internal Thien separators for mine, as well as installing dual Wynn poly filters. This setup works pretty well, although I expect the filters to need cleaning if I run my drum sander for an extended period. I imagine that a newer cyclone design wouldn't require the same cleaning.

The math worked for me because I got the DC practically free, plus I brought one of the Wynn filters over from my previous 1.5hp DC. If I were shopping for a new system and I had to buy the DC (say $400) plus 2 Wynn filters (say $250 for the pair) I might hold out for a cyclone.

As for your 4" pipe, you probably won't see much improvement with any system until you increase to 6". That will literally double the airflow and do a much better job. It's a lot of work, but you won't believe the difference, even with your existing DC. There is nearly no point in upgrading your DC until you size your ducting up. Good fun!

BTW, I used S&D 6" PVC which I found by calling a gravel yard. It's much cheaper than buying at Lowes, etc.