yea I think im gonna get the one at Lowes......

thanks for the replies

 

I just recently picked up a Sanborn (which was bought out by Coleman) 7hp/60gallon upright belt driven compressor for under $400 at Menards. It has a working pressure of 125-155psi, 11.5cfm@90psi, single stage and 230volt.

 

home depot has one that makes 29 cfm at 90 for 1,875.00

 

I've got a Husky 7hp 80 gallon belt drive twin cylinder oil reserve and it is great!

 

that sounds a little lite to be IR but if it is, spend the extra money on the T-30 select oil for it. It's a synthetic oil made for their compressors and I due believe IR will double the warranty if you do. Also spend a couple of buck on a good moisture seperator for the airline.
Make sure you have a friend or two to help move it and bolt it down as it is very top heavy.
I was lucky, came across an IR 5hp, single stage,16cfm @ 135psi, 60 gal compressor that was toppled in shippment. Only had to replace the air intake filter assembly($25). Picked up the compressor for $200.





read the tag carefully, the hp is peak rated.

 

Wow I've never seen that big a comp at the depot...That would have to be an 8 hp...

 

What do you all think about Cambell_Hausfeld?? Which is better Cambell Hausfeld or Ingersoll-rand??

 

Prob IR but in the compressor industry there are alot of names but few manufacturers.

 

take a good look at how the two are built, you will clearly see the castings are heavier on the IR. IR compressors are 100% duty cycle rated[does not need to shut off], CH is not.
Not saying that CH is junk, will probably work fine if this is just a home use (light duty)compressor. Now if you plan on restoring cars/trucks for a living out of your home, by all means buy an industral air compressor(Gardner Denver, Sullair, IR, Quincy)this is something you are going to run 5 days a week.

To have a good supply of air for just about whatever you want to run, an air compressor sould put out at least 13 to 16 cfm @ 90 psi. 90 psi is where most air tools are rated for air consumption and rated output.

 

I've got a Porter Cable 80 gal 2 stage 220 V :

http://img.photobucket.com/albums/v1...165600x450.jpg

Got it for $568 which was a smokin' deal. 17.4 SCFM @ 100 PSI.


Ron

 

dewalt. Father just bought one. They use them alot on tv so it must be a good one.

 

I've got one of the home depot oil-less uprights it's 25 or 30 gal 110V 135psi max. It's o.k. for light use, but I wouldn't ever buy one again. It's great because it's aluminum tank and really light to move around, but it overheats easily and can't keep up with much more than an air nailer or light duty use of a impact wrench. If you do sanding, blasting or anything like that, you need 220v oil type with a minimum of 135-150 psi. We used to have a big green compressor with a 5hp industrial 3 phase 220 motor on it. I don't have any idea what brand it was. It was old and covered in grease when I was born and it was still pumping air the last time I saw it, and I'm 30 now. If you like public auctions, keep an eye on the paper for mechanics sales and the like. Sometimes you can pick up a real good compressor for about 1/2 to 3/4 price of new.

 

Some notes on "Retail" Horsepower designations versus Actual Horsepower and
compressor calculations.

Some of the compressors available through retail outlets seem to have inflated
HP ratings based on "instantaneous" torque multiplied by RPM which has nothing
to do with ACTUAL horsepower or they are using breakdown ratings. You will notice the motors involved usually have
"special" or "SPL" when it comes to ratings on their nameplate. Our government
and the weights and measures people have done nothing to protect the general
public from this fraud. Check the tables below to find the electrical
requirements to produce ACTUAL horsepower.

Some information that may help you specify or evaluate any compressor is
detailed below.

In order to power air tools at their rated SCFM you can use the following
formula to find the estimated ACTUAL horsepower required:

SCFM x HPF x 1.1 = HP

HPF (Horse Power Factor) at tool rated pressure:
-----------------------
psi___HPF 1-stage___HPF 2-stage
-----------------------------------------------------
40___.107__________ ---
60___.136__________.128
70___.148__________.138
90___.170__________.156
100__.179__________.164
120__.196__________.178

1.1 is a factor used for figuring losses in the system.

single stage compressor: eg. 6 scfm @ 60 psi = 6 x .136 x 1.1 = .9 HP

Horsepower is also wasted by reducing the pressure through a regulator. This
wasted power can be estimated by using the following formula:

RIP= Regulator Inlet Pressure
ROP= Regulator Outlet Pressure
4 SCFM = Tool consumption

[ (HPF@RIP) - (HPF@ROP) ] x SCFM = HP waste

eg. RIP= 100;
ROP= 70;
[ .179 - .148 ] x 4 = .124 HP

Above tables and formula's from: Fluid Power Data Book, Womack Educational
Publications.

Compressors also have a "duty rating" involved. The duty cycle is based on the
percentage of time the motor is on while in use. The aluminum case or head
compressors will warp or creep under the heat load of continuous operation. This
creep will cause either internal or external leaks which decrease efficiency.
Decreasing efficiency leads to longer run times and more damage. The electric
motor itself has a temperature rise and a service factor as well as a duty
cycle. The "special" motors do not specify these factors but you can guess what
they might be... Service factor-.8; duty cycle- intermittent.

Actual Continuous duty motors have fairly well established current draw versus
voltage and HP ratings. The values below also have a "fudge factor" built in for
line-voltage variations. There is no "free lunch" when it comes to horsepower.
See the following table for some generic values:

Single Phase Alternating Current Motors Full Load Current in Amperes:
-----------------------------
HP_____115V_____230V
-----------------------------
1______16_______ 8
1.5_____20______10
2______24______ 12
3______34______17
5______56______28
7.5____ 80______40
10____100______50

The above values are from the National Electric Code and reflect their use in
calculating branch circuit requirements. Also notice 115V values are twice the
230V values.

The following values are taken from the catalog of a major manufacturer of high
efficiency industrial motors for compressors. They will more closely resemble
the values you should see on motors on high quality compressor units.

Single Phase Alternating Current Motors Full Load Current in Amperes:
---------------------------
HP_____115V______230V
---------------------------
1______16________8
1.5____ 20________10
2______24________12
3______32________16
5______42________21
7.5____ --________33
10 ____ --________44

You can see that efficiencies increase as motor size/HP increases.

To make things more confusing some retail manufacturers seem to "calculate"
their SCFM ratings based on displacement and rpm. Commercial manufacturers
actually test their units or use tables supplied by the pump manufacturer based
on testing.

Do not buy the maintenance free oil less type compressors. They are not only
horrendously noisy they wear out VERY quickly. They are usually made of aluminum
with the motor directly coupled to the compressor and are usually good for just
a few hundred hours of operation (if you are lucky).


Just in case the semi official HP explanation:
==============================================
An estimate of motor horsepower can be made by the formula horsepower =
(amperage x voltage) divided by 746 watts (the number of watts in 1 hp). For
example, a motor rated at 15 amps running on a 120 volt circuit would
theoretically produce about 2.4 horsepower. In practice it doesn't work this way
because a motor can't convert all of the electrical energy it uses into
mechanical power. Some energy goes into magnetizing the rotor and windings. This is recognized by the use of a power factor, which is generally represented by a 20 percent loss, meaning the motor can use only 80 percent of its rating. In the
example above, a closer estimate can be made by multiplying the result (2.4 hp)
times 80 percent. The rating would then be 1.9 horsepower. This power factor
rating goes up as horsepower increases.

Motor manufacturers do not use this formula to determine a motor's output.
Instead, motors are tested on a dynamometer (a mechanical device that measures
torque). The horsepower is then determined with the formula:
horsepower = (torque [in ft. lb.] x rpm) divided by 5,252 (constant).
This then becomes the NEMA rating.

It is important to recognize that NEMA standards for motors are based on the
ability of a motor to deliver its nameplate rated horsepower continuously, 24
hours a day, under full load. Some motors are also time rated to represent the
period of time a motor can deliver its rated horsepower without overheating.

Machinery manufacturers are not required to comply with NEMA's rating standards
and sometimes take liberties with claimed horsepower ratings. Any electric motor
is capable of producing far greater power than its continuous-duty rating. For
example, a 3 hp motor can actually produce up to about 7 hp for a short time. It
will then reach its breakdown point where it may overheat and burnout. On
machines that have induction motors the words "maximum developed horsepower" and "peak power output" are marketing words for a motor whose claimed output is near its breakdown point. For example, I recently purchased an electric power tool
rated at 3.5 "peak" horsepower. The nameplate data for the motor states that it
runs on 120V single-phase current and draws 12A. Doing a quick calculation, the
motor probably has a continuous rating of about 3/4 HP.

-Sorry about the ragged text justification. This information was lifted from my files.

 

Wow great stuff. Now where can I get an efficient 7.5hp compressor????

 

dont buy a oilless way to noisey