Need bigger dust collector

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Forum topic by JohnTHoward posted 09-10-2016 11:45 PM 323 views 0 times favorited 6 replies Add to Favorites Watch
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1 post in 45 days

09-10-2016 11:45 PM

Topic tags/keywords: dust collection

Many years ago, I bought a 1 HP DC and connected it to my cabinet saw. I would occasionally move it to my joiner or my “portable” planer. Life was good. Then I upgraded my planer to a Jet 15 inch beast. The 1 HP DC could not get the dust and chips out of the planer fast enough and I spent more time clearing clogs than planing wood.

Question 1 (cheapest alternative): could I buy a 2 HP DC from Harbor Freight and connect it in “parallel” with my 1 HP unit?

Question 2: Would the 2 HP Harbor Freight unit provide adequate DC for the planer alone?

Question 3: What HP/CFM is need for short-distance connection to this planer alone?

Question 4: What HP/CFM is needed longer-distance connection to all tools (one at a time) including this planer.

Not looking for a lesson in fluid dynamics, just experienced recommendations.


6 replies so far

View Redoak49's profile


1820 posts in 1410 days

#1 posted 09-11-2016 12:19 AM

No…connecting in parallel will not work.

The 2 hp HF dust collector will at best give you 600 cfm and would work with the planer if connected with not too much pipe. It will suck up the chips but not as good on the fine dust. The advertised data on the HF unit over rate it significantly. Testing data shows a max of about 600 cfm with max static pressure of about 6 inches.

While many are happy with the HF unit, it has a small impeller and limited capability in terms of CFM and static pressure. Will it work….yes. how well it works is a different and subjective answer.

A better question is what are your long term plans for a shop. I would recommend a better unit that is more powerful but of course that is more dollars.

Sorry about the specs and more technical stuff but when you ask questions like you did it is not really possible to avoid the performance.

Just to be honest, I went from a Jet Vortex canister to a 5 hp cyclone because I wanted to plumb it through my shop and suck up the fine dust. Some may say overkill but I am getting older and want to do a good job getting the finer stuff.

View josephf's profile


124 posts in 1518 days

#2 posted 09-12-2016 02:38 AM

hey thanks for the actual specs on the harbor frieght . i always figured it wasn’t what the specs said .
i have a 1 1/2 powermatic with a ebay cyclone . generally does fine with 15 ” planer .cyclone has plugged twice with big shavings . no shrowd on planer so not surprised it doesn’t get everything .
if i were to another it would not be smaller then a 3hp .that being said i bought my dust collectors used and for less .
oh i go direct to the tool i am using .just one flexible hose .

View TheFridge's profile


5678 posts in 908 days

#3 posted 09-12-2016 02:46 AM

No paralleling

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View Fred Hargis's profile

Fred Hargis

3847 posts in 1915 days

#4 posted 09-12-2016 03:30 PM

You could buy the biggest DC made, and if you still connect it with 4” flex, it might not not do a whole lot better than what you have. Here’s what i would suggest is you want to keep spending down: If you put a larger port on the planer (I’m guessing the one you have is a factory 4”) you can more more air. I catch everything except an occasional stray chip on my Delta 15” with a 5” port (that also has a 5HP DC pulling on it). If you go to a 5”, the minimum DC I would suggest would be one of the 1.5 HP models (true 1.5 HP) with an 11” impeller. On the point redoak made, the HF is about 1.5 HP, but has roughly a 10” impeller. Spend a little more and move up to a 2HP unit with a 12” impeller and you may find it to perform completely to your satisfaction; of course, that unit will require 240V power. But with a 15” planer, you generate mountains of chips, so having a separator of some kind like a Thein on top of a garbage can is useful, they are easier to empty. Be aware, any thing like decreases air flow, so having the largest unit you can get is helpful. But the larger unit needs larger ductwork to allow that air flow. So with the 2 HP, and 6” or so ducting you increase your DC capability more than a little.

-- Our village hasn't lost it's idiot, he was elected to congress.

View Mike_D_S's profile


173 posts in 1636 days

#5 posted 09-12-2016 05:55 PM

I’ll contradict what some other say slightly on the HF dust collector being 1.5 HP. Like the OP, I’m looking to upgrade my DC system. I currently have the HF system with an upgraded felt filter bag and spent about an hour taking current draw measurements this weekend on my setup. I’ll cover what I found below and obviously amp draw is not CFM, but they are related so I consider this qualitative testing.

It’s important to remember that the performance of the system is subject to 3 basic things:
1. The size of the motor – how much total work can be put into the system
2. The size of the impeller – how efficiently that work can be converted to air movement
3. The system losses – generally friction losses on both the intake and exhaust side.

So let’s start with the motor, here are two scenarios (the numbers are rounded a bit to make it easy):
A. My system completely assembled with the 5” to 4” splitter, one blast gate open with 10 ft of 4” line draws about 9.9 amps at 115V for 1100 watts, so 1.5 HP in, so call it roughly 1 1/4 HP at the impeller with losses? This is with a seasoned felt filter bag which I did beat out a bit prior to the test.
B. Disconnect the motor exhaust hose from the filter pan and let it blow straight, leaving the 10 ft of 4” hose on the intake and the system draw about 13.3 amps at at 112V for 1500 watts, right at 1.9 HP, so maybe 1.5 HP at the impeller.

So from this basic testing, the motor is definitely capable of delivering approximately 2HP of work and assuming the motor ratings are ok, can do so without burning out. But, the complete system is only capable of delivering about 1.25 HP of effective power in stock configuration. So the system performs like a quality 1.5 HP DC system, but the motor itself is not 1.5 HP.

I then followed up with a few additional tests
A. Exhaust hose not connected to pan, both 4” blast gates open, 10 ft of hose on the one side
B. Same as A, except no hose and both gates open.
C. Exhaust hose not connected to pan, 5” to 4” inlet splitter removed, essentially just the blower and outlet hose.
D. Exhaust hose removed, plastic rectangular to round adapter left on the blower outlet, 5” inlet splitter removed.

All four of these tests basically produced between 13 and 13.6 amps at about the same voltage, So my conclusion is that this is the practical limit for this impeller/motor combination. I also did a few additional tests were I put different bends in the exhaust hose (180 deg, 90 deg) and different bends in the 10 ft 4” hose. None of those made much difference overall as with the 10 ft hose with a complete 360 turn and the exhaust hose bent in a 180 degree bend, I only got the amp draw down to about 12.7 amps.

So basically my testing says to me that I should focus on two areas, improving the air flow on the exhaust side and getting more of the available power into the system in the restricted condition.

For the first part, the biggest bang for the buck on the HF collector is to improve the flow on the exhaust side. Switching to a Wynn filter with it’s much larger surface area would be an obvious improvement and a bolt on solution.

If someone was definitely going to add a cyclone style separator (SDD or other) I would also consider simply doubling the filter bags and using an additional filter bag in place of the plastic collection bag. This would essentially double your surface area. Now there are potential downsides to this if your cyclone doesn’t work all that well, but might be a good option. I may consider ordering a replacement filter bag just to be able to see the effect on the amp draw.

To get more power into the system, this is where swapping to the Rikon impeller might be good. The larger impeller should essentially ‘demand’ more power from the motor which it should be able to provide. There have been a few posts showing the impeller change resulted in 10-15% higher current draw with everything else being the same.

So If I put my redneck math hat on, if 9.5 amps for my stock setup is say about 400 CFM, then going to a better filter setup (lower static pressure) and using the bigger impeller (more work in) I could maybe get my amp draw up to 11 to 11.5 amps, so as a complete wild ass guess maybe I get to 600 CFM? But I have to spend $300 to get there ($175 for the Wynn + $125 for the impeller). Call it $500 if I add the SDD. So with the cyclone, my total cost of ownership for the modified HF is +-$700 and I have figure out the mounting.

This is where the economy question comes in and the cheapass in me comes out. For $1000 I can pick up a 1.5 HP mobile cyclone and probably get 600 to 700+ CFM usable. Or for $700 I can have maybe 500 to 600 CFM by modifying my HF setup? I know I should just buy the cyclone, but coming up with money all at once is tough to stomach.

Hopefully these number help and maybe other guys who have made some measurements can chime in. From some of the other posts, it seems like 9 to 9.5 amps is pretty typical for the stock HF unit.


-- No honey, that's not new, I've had that forever......

View Kelly's profile


1051 posts in 2366 days

#6 posted 09-13-2016 05:57 AM

I have a 1 horse Delta with an after market bag, a Jet 1-1/2 horse with a can, a Jet four bagger 3 horse with after market bags and, a Harbor Freight 2 horse with an after market bag.

The one horse is out the door to a friend. It was replaced by the HF 2 horse, which is a night and day improvement over the 1 horse, regardless of what anyone here says.

I pulled my dust scoop off my miter pending replacement with a better design. Meanwhile, the hose is just attached near the back of the blade. The 1 horse left a lot of dust on the floor. The HF 2 horse leaves only a little.

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