will this comperessor be enough?

[kill_shot]

I am on the market for a compressor that can run air tools and sprayers ect.I don't want to spend to much on it but still want a good one that will be enough.I am looking at a craftsman professinal 7.5hp 120v one it only puts out 5.1 scfm at 90 psi which i think seems alittle low for 7.5 hp but anyways what i was wondering was if I was using say a orbit sander that needs 15 scfm at 90 psi would i still be able to run it at full speed until the pressure got down then wait till it pressured up again or would it always run slow?I was going to get a 220v but my garage won't have it for a while now.also how hard would it be to add a bigger tank to the one it has?anyone done this with pics?

[darkstar]

don't get it, or any oil-free unit, you will be disappointed. shitty air delivery, LOTS of noise!

Any kind of rotating air tool (sander, grinder, etc.) needs a good air source, which that compressor definitely is not.

[u2slow]

Let's see if this 7.5hp rating holds any water:

7.5hp * 746W/hp = 5595W

5595W / 120V = 46.625 Amps

The most that you can run on a 120V/15A circuit is ~2HP.... no matter what outrageous claim the manufacturer makes.

You're simply not going to get more than 5-6scfm on a 120V/15A circuit.

[aloharover]

Originally Posted by u2slow

7.5hp * 746W/hp = 5595W
5595W / 120V = 46.625 Amps

Thanks, I never looked at it that way before.
So a 20 amp circiut is only 3.2 horse.
So a 6hp table saw or 5hp power washer is just hogwash?

[maddog]

I did a lot of searching for my compressor and this is the best I could find for thr size, cfm delivery rate and price. It runs on 220v buit well worth the investment of adding a dedicated circuit. This is the link.

http://www.toolsusa.com/compressors/...cat=compressor

R7580V-601 Tri-Max™ Series 7.5 H.P. Vertical Air Compressor

The Ranger TRI-MAX™ Series compressors have earned their reputation as an industry leader by meeting rigorous demands placed on them every day in businesses like automotive and body repair to manufacturing and industrial service. These power-house air compressors feature the renowned TRI-MAX™ extreme-duty three-cylinder pump that has been designed and manufactured to operate with maximum efficiency under all load conditions. The 100% cast-iron TRI-MAX™ Series pump features a "W-3" configuration that provides 360° cooling efficiency and simple splash lubrication for total reliability. A large pump that puts out little noise and a lot of power is due to the slower RPM speed and efficient two-stage design, a special feature of every TRI-MAX™ Series pump. Because they operate at slower speeds than other compressors and feature large-diameter finned copper tubing between stages, they have a lower operating temperature, which ultimately achieves maximum compressor efficiency. The TRI-MAX™ Series features durable cast iron construction for longer life and less downtime, and heavy-duty disc-type valves for efficient airflow. The result is more air per horsepower. Includes pressure gauge and dual service valves.

Model No.: R7580V-601
Tank : 300 L / 80 Gal / Vertical
Voltage: 208-230 Volts
H.P.: 7.5
Phase: 1
Hertz: 60
Pump: 3 Cylinder / 2 Stage
RPM: 1180
Lubrication: Oil
CFM @ 90 PSI: 25.3
CFM @ MAX PSI: 18.9
MAX PSI: 175
DIMENSIONS: L 73" x H 37" x W 24"
SHIP WEIGHT: 486 LBS.

[PAToyota]

Saw that 7.5 horse Craftsman and then saw the 120V and said WTF? My 5 horse two stage 220V is on a 40 amp circuit...

[GoingOffRoading]

I have this guy

http://www.sears.com/sr/javasr/produ...nk+Compressors

It's not 220v and it's a little noisy but it works great for me... I can run everything from impacts to air saws... BUT the thing does get bogged down if I run a cut-off wheel for an extended period of time.

[blown4x4]

http://www.sears.com/sr/javasr/produ...id=00916561000

I love this thing it does everything I have asked it to do.

[jpnjim]

Originally Posted by aloharover

Thanks, I never looked at it that way before.
So a 20 amp circiut is only 3.2 horse.
So a 6hp table saw or 5hp power washer is just hogwash?

YES!


They rate their Vacuum's way over too.
I think Sears has a 115v 6.25HP shop vac

They claim some "Peak HP" bullsh!t, but 6.25HP is 6.25HP (40.5amps @ 115v), I never understood how they could get away with outright lying like that

Craftsman does make some good compressors, but I wouldn't buy one just because they outright lie in their specs.


Answering your original question, if it uses 15 scfm, get a compressor that supplies that, or your not gonna spend much time sanding, and alot of time waiting (& unless it's 100% duty cyle, burning up the compressor).

Can you find a orbital that needs less air?
Usually cheaper air tools use (waste) alot more air than the "good stuff".

[u2slow]

I notice these oil-less compressors don't have a duty rating.

This article attempts to cut through some of the smoke & mirrors:
http://www.kmstools.com/pages/compressguide/index.htm

I have an 2-cyl oil-type portable 20 gal compressor. 240V, 3.5HP, 10.3cfm@90psi, 80% duty cycle. I use it for wrenching, filling tires, and blowing things off. It runs continuously when I use a cut-off wheel though.

[kill_shot]

ok I looked into better air tools and I found a .5hp orbital sander that spins 1200rpm and only uses 5 scfm at 90.I just got quoted on 220 and it is way to much to run from my house because they have to put a new pannel in the house and then run 100 feet of baried cable so i am not getting 220 if I can help it for now.I want to start painting and eventualy paint my truck.the only experiance I have is spraying oil tanks with a gun but it was to an iron horse 16 scfm at 90 compressor with no filter because finish wasn't a big deal.I want to get a compressor that runs off house hold does anyone have any recomendations on a good compressor and what kind of filtration system should i get for it.is there any compressor that will suit my needs with out having to get 220?

[kill_shot]

anyone had any experiance with porter cable?they have a 2 hp oil lube horizontal.it is 15 amps@115 volts.rated at 8.6 at 40 and 6.8 at 90.this should be enough air for my needs but would the air quality still be bad?anything wrong with this one?

[69CJ]

my cheapo 33gal oiless crapsman committed suicide a few months ago. I worked it hard, so the premature death was my fault. Even though, swore to never buy one again as I really needed more air. The death of the compressor led me to an upright 60gal TSL4 or something like that, 5HP Ingersoll-Rand, 175psi, 11.8 cfm. I bought the floor model from SEARS as they were discontinuing that model from their inventory. Grainger listed this unit at 1199.00, Sears had it at 999.99 regular price. I watched it for a month or two while I expanded my garage shop to make room for the compressor. Sears dropped it to 949.88 and threw in the startup synthetic oil - which extends your warranty on the pump for two years. The oil goes for $50-ish IIRC.

Heras a hint for leverage on tools when your visit your sears store... If the cents on the price tag read "88" it means they are discontinuing the item. It's a clue to the sales staff to get the stuff out of there. I saw the price drop and the "88" cents piece and asked about it... they knocked off another 10% without asking and threw in delivery (another $40) so they could reclaim their floor space.

The only thing wrong with it? The guage was busted.......... Good compressor, good CFM, quiet, excellent price and warrenty.

I'm redoing my airlines in the garage. They were heavy wall copper with drops about every 5 feet. Now I'm using 3/4" galvanized. Copper is easier to work with but the galvanized is supposed to be stronger/safer.

J.

[Goat]

Originally Posted by jpnjim

They claim some "Peak HP" bullsh!t, but 6.25HP is 6.25HP (40.5amps @ 115v), I never understood how they could get away with outright lying like that

They didn't there was a class action lawsuit filed against a whole bunch of companies for this...if you notice all the new tools have that HP rating and in small letters next to it is the running rating...those HP numbers are motor stall numbers.

If you want to run rotary air tools you need something in the range of 15-20 cfm @ 90 anything lower and you will not be happy. Remember that running a comp 100% DC increases water contamination of your air.