Official Luthiers Forum!
http://w-ww.luthiersforum.com/forum/

Harbor Freight Dust Collector???
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=13281		 Page 1 of 1
Author:  Blain [ Sat Aug 18, 2007 3:27 pm ]
Post subject: 
Harbor Freight currently has a dust collector on sale for $179.00 and if you use the coupon on the sale you can get 15% off a single item. This dust collector is regularly priced at $249.00. I know a lot of the Harbor Freight tools are lacking in quality, but I'm wondering if anyone has this dust collector or would reccomend it?

Should I steer clear of this one? My thinking is that it's going to be a 1600 CFM Dust collector. That's what it will do and that's all it will need to do. Am I wrong in thinking that one 1600 CFM dust collector is the same as another 1600 CFM dust collector or is there a lot more to it?

Would any of you reccomend another dust collector in the same price range that would be "more bang for the buck"?

here are some of the specs:
Locking casters
Lockable on/off toggle switch
Motor: 2 HP, 110V, 14 amps, single phase
Bag capacity: 70 gal.
Air flow: 1600 CFM
Single stage
Filtration: 30 micron
Hose inlet: 4''
Author:  KenH [ Sat Aug 18, 2007 3:40 pm ]
Post subject: 

Hey Blain!


Sounds like a good deal for the money. It will probably do fine for a small shop application too. The only negative thing that I can tell you about harbor freight tools is that their electric motors are not rated correctly. If the label says it is a 2 hp, you will probably get a motor that is really a 1 to 1.25hp motor. Still big enough to handle the size rotor that it will be turning, but the label is over rated. I just plugged  the figures you listed above into an online electric motor HP calculator, and this is what it says:























Voltage: < =:resetanswer(); size=10 value=110 name=voltage>
Full Load Amps: < =:resetanswer(); size=10 value=14 name=fla>
Efficiency: < =:resetanswer(); size=10 value=0.65 name=efficiency>
< =calculate_(); = value=Calculate> < =reset value=Reset>
True continuous Watts: < readOnly size=15 value=1001 name=watts>
True continuous HP rating: < readOnly size=15 value=1.342 name=hp>
(rounded to 3 decimal places)


My guess wasnt off by much ! This may actually be closer to the figure I quoted above if the service factor (efficiency rating) is lower.


I have to wonder about the 1600cfm rating as well. I'm sure there is an online calculator to check the figures they give against known standards, but I dont know where one is right off hand. Either way, it should be big enough to handle a small luthier's shop.


Hope this helps!


Ken
Author:  Blain [ Sat Aug 18, 2007 3:58 pm ]
Post subject: 
Thanks Ken, that does help a lot.

Currently all I have is a Rigid Shop vac and the cfm is a whole lot lower than 1600 (I think it's rated at 187cfm).

I may look at some other dust collectors on the market and compare to see if I want to spend a little extra for something else, but I think if my memory serves me correctly I would have to shell out an additional $100 for something comparable so that may make the Harbor Freight collector look better. I just hate to get it if I'm going to regret it like I did with their band saw.

Thanks again for plugging the information into the calculator to figure the true HP.

Author:  David Collins [ Sat Aug 18, 2007 6:58 pm ]
Post subject: 
They must have tested the cfm with no filter bags, and the inlets facing
upwind in a hurricane. My old cyclone has a true 2hp 3-phase motor and
6" inlet and I estimate it at around 1200cfm.

As to rating things like horsepower, companies can get pretty creative.
Craftsman can make a shop vac with a hair drier motor that draws about
3 amps, and somehow rate it at 6 hp.    I think they can calculate the
maximum force for HVAC systems not by force produced at the motor,
but by maximum potential energy. So if you plugged the input of a shop
vac, ran it until the motor almost burnt out, then detonated the canister I
think you might get an instant energy burst of near 6hp as it imploded. I
guess a bit of creative marketing is to be expected though. Either that, or
more likely a plain simple lie.


That aside, if it can pull 700cfm, it's fine for just about any small shop.
You just won't be able to leave more than one or two blast gates open at
a time, and it might not be enough for something like a 48" wide belt
sander. What you should be concerned about is the 30 micron bag. That
would be fine for a planer or jointer, but it would just blow most sawdust
straight through. If you're putting the dust collector outside that's fine,
but if it's going to be inside your shop you should look for a filter or bag
size of 1 or 2 microns.

The smaller the filtering size, the less efficient and the more hp you'll
need for the same cfm. If you're stuck in a small shop I would definitely
favor the smaller filter over cfm. As long as you run your pipe cleanly and
don't leave too many blast gates open at once, I think you'll do better with
less cfm and better filtering. The Delta's seem pretty good for this, and
don't cost much more.

P.S. If you have 3-phase, I have an old Cincinnati 2hp blower that I'm
getting rid of. Trash can style cyclone, no filters or bags, and really loud,
but cheap.
Author:  Blain [ Sun Aug 19, 2007 3:40 am ]
Post subject: 
Thanks for the tips guys. I had no idea what the 30 micron bag was, so I'm glad that y'all brought this up.

Harbor Freight sells a 1 micron upgrade kit for $169.99 so as Todd said, there goes any savings I thought I got.

Seeing this now, I think I can say that I'd be better off trying to find something of more quality for around the same price range.



Author:  uncledave [ Sun Aug 19, 2007 5:03 am ]
Post subject: 

David Collins said:   If you're putting the dust collector outside that's fine,
but if it's going to be inside your shop you should look for a filter or bag
size of 1 or 2 microns.


>>>>>>>


I'm setting up a shop right now.  Haven't purchased any dust collection yet, but plan on that being one of the first things.  My question is concerning placing the unit inside, where I'll be able to hear it very well, or directly below the shop in a 7 foot tall "crawl space".


What I worry about is extracting all that dehumidified air from my  shop and replacing it with good old hot Texas air vs living with the noise.


What are your opinions?  And thanks, I VALUE you guys opinions.


Dave


Flower Mound TX
Author:  WaddyThomson [ Sun Aug 19, 2007 5:42 am ]
Post subject: 
If you get a cyclone, can't you put the actual cyclone outside and have it vent back inside to a filter on the system?  Seems like the Oneida ones are weather proof.  Or, in your case Dave, you might be able to put it in the crawl space.  Some are shorter than others.  Don't know if 7 ft. will do it.
Author:  jsimpson [ Sun Aug 19, 2007 7:02 am ]
Post subject: 
I've owned a HF dust collector...probably the very same one...for 4 years now, and it's been great!  No complaints at all, except for that the bag is a little nerve racking to put back on after you empty it. 
Author:  WaddyThomson [ Sun Aug 19, 2007 9:04 am ]
Post subject: 
Well, there you go.  Do you get a lot of dust blowing through the bag?
Author:  fryovanni [ Sun Aug 19, 2007 1:22 pm ]
Post subject: 
Ken, I think you may be thinking about power factor(which is needed to figure out your input wattage, and relates to the current and voltage phase relationship), service factor is a rating that tells you what percentage of the full load current the motor can run at continuously without damage(typical rating would be 1.15 or 115% of the FLA). Efficiency is another rating. That relates to power put in and power at the shaft. Most small motors have an efficiency rating close to 80%, larger motors tend to be higher. Of course not all X HP motors have the same torque curve, bearing quality, insulation quality, cooling ability and so forth. So depending on the usage one motor may provide you with much better effective performance.

For a motor to draw 14 amps @110 volts and rate at 2HP. It would need to be better than 90% efficient. This is not unheard of as standards for efficiency are being required to be higher. That would be a pretty optimistic sounding number for a reasonably inexpensive motor.
Author:  David Collins [ Sun Aug 19, 2007 6:20 pm ]
Post subject: 
True, the hp for most motors will be rated at maximum load. This means
that they increase the load on the shaft until it stalls. Immediately before
stalling will be the highest amperage drawn that they can use to figure
power in watts or hp based on voltage and amperage on the motor. Once
the motor is installed in a tool however, companies can get much more
creative.

Imagine a table saw for example, they may be able to figure hp as just
under the force required to instantly stop the saw with a heavy blade at
full speed. This is the stall wattage of the motor, plus all of the built
up inertia in the blade itself. Or an air compressor can be rated at the
total stored force in the tank if it were to be instantaneously released.
This is why most of the compressors you see in box stores will have
different ratings. They may all have the exact same 1 hp rated motor
(which it probably isn't), but as the tank size increases it will have the
ability to store greater potential energy. That's how you can find a "5hp"
compressor that only draws 12 amps at 120. It won't perform any
better than their 1hp under constant use, but that's marketing for ya.
Dust collectors and vacuums can use the same trickery, only with suction
power rather than compression.

Even after all these misleading (but still legal) possibilities to boost their
clams, most manufacturers just outright lie. My physics professor was
quite an avid woodworker and a good friend of mine. He got most of his
large tools either totally free, or at least a prorated refund after writing to
the manufacturer. He said that if the claims boosted their sales enough
then paying off the very few who called their bluffs was pocket change.
The worst offenders are of course those targeting general consumers,
rather than professionals. In the same way that a professional PA power
amp is more likely deliver it's claimed wattage than a home or car stereo,
a Quincy air compressor is more likely to have accurate ratings than a
Campbell Hausfeld.

If you were good enough with your math and physics you could probably
buy the dust collector, then get a healthy refund after a threat to call your
attorney general.
Author:  David Collins [ Sun Aug 19, 2007 6:53 pm ]
Post subject: 
I found a good article on this subject.

http://
users.goldengate.net/~kbrady/motors.pdf

This chart (clipped from the article) is a good reference to keep on hand.

Author:  Bill Greene [ Mon Aug 20, 2007 12:48 am ]
Post subject: 
[QUOTE=ToddStock] Finally - systems with chip/dust drums, like the cyclones and some dust collectors, are much easier to empty...about the time you've gotten your 5th face-full of fine dust changing a bag, you'll start thinking about whether some sucker can be induced to buy your DC so that you can finally get that Dust Gorilla you should have saved your pennies for to begin with.[/QUOTE]

Amen. Thank goodness I had a buddy who had some experience with dust collection prior to building my system. He told me the exact thing, and then I got to SEE one of those giant bag systems. What a mess! In the shop where I saw it, it certainly caught most of he dust but that bag was the nastiest thing imaginable.

Now I vent my exhaust straight, literally straight, out of the foundation of the house. No longer than I run the system, it moves the humidity only a percentage point, or two at the most. I use 6" mains, and 6" drops, 3hp, 220v, turning an 16" impeller, and dropping the dust chips into a large 55gal trash can. Works like a dream.
Author:  fryovanni [ Mon Aug 20, 2007 12:35 pm ]
Post subject: 
NEMA standards for high efficiency motors and legislation are trying to improve the efficiency of motors. There is a lot of cost associated with low efficiency motors. Of course getting a handle on larger or industrial/commercial motors is where most of the focus is right now, but motor manufacturers are being forced to move tward better performance. I would expect that down the road we will see better motors come more into the mainstream. I don't want to imply that you should assume the motors are more efficient, but this is the trend or where the government wants the manufacturers to go.

A good source for info on motors is the Granger catalog. Granger
They offer a glossary of terminology, good basic style information, explanations on how to read a nameplate. As well as selling a variety of motors so you can see the cost differences in differnt styles.

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/