HF 2hp DC ... and the CFM is?

[W Canaday]

I have a fantasy and I'm willing to share it with the select few who visit this news group.

Ready?

In my fantasy I fire up my DC (hummmmm) and then I walk over to my planer and switch it on (whirrrr). I set the table and feed in a piece of rough looking lumber and out the other end comes nothing but a satiny smooth board.

No chips, no dust ... just dimensioned and surfaced lumber.

I told you it was a fantasy.

I recently bought the afore-mentioned DC. Although I have NO clue how I'm going to slide this past SWMBO, now I want to know the CFM's of the DC I currently own so I can make a better estimate of the CFM's I'll need on its replacement.

That number is not on the website, in the documentation that came with it, or on any of the stickers affixed to it. In other words, Central Machinery would rather I not know.

It's late night Saturday as I write this and I really doubt if I'll get anything except either a recording or a moron at their 1-800 tech assistance number.

But maybe one of you might be able to offer a reasonable guess (or even offer up the correct number!)

TIA

Bill

[Toller]

They claim 1600cfm. If it does half that I would be shocked. I don't know how big your planer is, but my 12" is not particularly demanding; almost any DC would handle it.

[Greg O]

My guess is 800 CFM, maybe 1000 CFM with no hose, and on a leap year. Most companies are wishing when it comes to CFM numbers for their dust collectors anyway! I have a HF 2HP, (Sears HP), dust collector. Hooked up to my 6" Jet jointer and my Delta table saw at the same time with 2 - 4" hoses it does a wonderful job of sucking up chips, don't know why your experience will be any different! Greg

[Jim]

I've had the HF DC for about 18 months. I've been more than pleased with it. Hooked up to Delta 13" planer and Ryobi BT3000 table saw. It has taken everything I've sent down the line with no trouble. I did change out the OEM bags for some 3 micron ones.

Jim

[Tyke]

I think you should consider CFM (which is a rating at the entrance nozzle of the DC, namely no pressure drop for the line) and head (how much suction).

It is not possible to connect our tools to the DC without using some connection line which results in pressure drop. Different models have different designs resulting in different Flow vs head curves. Cheaper units tend to drop off CFM more as pressure drop in the line increases.

This is one reason why smaller micron bags are recommended - they lower pressure drop which provides for increase in flow.

The good manufacturers post their performance curves. Do not hold your breath to find HF's curves.

There are many good DC's on the market. For my recent purchase I went with a model with the "cannister filter" a pleated fabric inside a steel cage. Works great and easy to clean. These units have a plastic bag on the bottom since there is so much surface area in the cannister they do not need the botttom bag to be porous. This means I can now see when to empty the bag.

I upgraded from a 3/4HP to a 2 HP unit. The old 3/4HP was adequate, but the

2 HP unit is much better - increase in flow and head.

Dave Paine.

[Toller]

I am not criticising it. For $170 it is probably a reasonable value. But the motor draws as many amps as a Jet that claims 650cfm. The Jet is understating its capacity (unlikely), the HF is a superior design or manufacture (unlikely), or the HF is overstating its capacity (likely). The Jet is $85 more; so the HF (assuming it does not break in the first couple years) is a good value.

[James "Cubby" Culbertson]

Unfortunately, most Mfg's overstate their CFM by a sizeable amount so even if they can tell you what it is, it won't be right, more than likely. A magnahelic or pitot tube setup would be the most accurate to figure this out but the cost of those will probably be close to what you paid for the DC. I have found Bill Pentz's site to be fantastic in my quest for a DC. He describes how to measure the CFM, what you really need to remove the "dust" (not just chips), etc.... Check it out:

I believe. Cheers, cc

[W Canaday]

Out of the exit side of the planer, very little is escaping. But there is a build up occuring at the entrance side.

I'm still getting dust on the top side with my zero clearance insert on my Craftsman 10" TS. Little to no dust seems to be escaping elsewhere.

I have a "trash can cyclone" atop a 55 gal fiber drum. While Bernoulli and I are not on a first name basis, I don't think that the additional volume in the system (vs the recommended 30 gal. can) would make any difference after a moment of sucking up the additional idle air. My joints are tight. On the TS I closed up the gaping hole at the back by covering it about 50% with duct tape. I could not find a pre-manufactured port for the planer so I blocked off the existing exit with a scrap of plexiglas (kinda cool to watch the chips swirling up!) and cut a 4" hole in the top plate (entering the exit chute) to which I riveted a 'universal' 4" port. I am only running one machine at a time.

The only 'ugliness' that I can come up with so far is the use of corrugated hose. But even there, the max run so far is 20' of heavy duty (non-collapsing) hose. This would induce turbulence and reduce the flow SOMEwhat ... but would it be enough?

Are my expectations for a DC too high?

I'm asking that in all seriousness.

Bill

[arw01]

Also the impellar on the HF is smaller than the jet. However, as a HF DC owner, it does it's job very well.

Photo of impellar here:

[Greg O]

No system will get 100% of the dust. An over arm guard on the TS will help get just about all of it. As for the jointer, you fail to state the manufacturer, it may help. A larger hose or pipe to the jointer may help too. Again I doubt you will get 100% of the dust. I did not block the back of my Delta TS at all. I taped a piece of card board across it once, but did not see a difference. You need air movement to do any good, sealing off every opening will reduce the effectiveness of the DC. I really need to measure the HF DC. I have the tools available at work to do so, I just never get to it. Greg

[Bob G.]

My son tested my 2 Hp Grizley and my 1 Hp Penn State DC'ers a few years ago using one of his measuring devices...

At the suction port the 2 Hp ran in the 800's and the 1 Hp in the

300's... measuring the 2 Hp unit on my Drill press which is located about 30 foot from the DC came up with a figure of about 200.. under 200...

The 1 Hp is located 3 foot from my planer and it works just fine... except the bag is too small and fills quickly...can not for the life of me remember what "we" measured at the machine for it however

I made the mistake 15 or more uyears ago when first purchased the Grizley and duct taped all the air spaces under my Cabinet saw ... reduced the dust colection to zero...had no air movement...

I like to remove the fine dust...could care less about chips...my jointer is not even connected...chips fall in a box...

Bob G.

[etoolclub]

We posted a pretty descent article on dust collection that might help you out in the future.

can find the right calucations for CFM.

Let me know if you need any additional information, and I can get a professional dust colllector technician to send you more information.

Thanks and good lucK! Brandon The Support Team