Time to upgrade the air compressor... Questions?

[CGCINC]

I bought my Craftsmen compressor because it was on sale and cheap... What I needed to do was ask myself if it would do the things I need it for. It doesn't! It is rated at 1.5 running HP and 33 gallon tank

So I found this pump at HF and I'm wondering if I would be able to power it with the existing motor on my compressor?
http://www.harborfreight.com/145-psi...ump-67697.html

Harbor Freight pump..


My compressor..

[DaveO]

Unfortunately the manufacturers sell to consumers by bragging about HP, just like on lawn mowers, or like amps on speakers or power tools. Another metric to look at is the CFM (cubic ft per minute) rating of the compressor, and match it to the tools you plan to use. (Apologies if I'm re-stating the obvious, here.)

[CGCINC]

Unfortunately the manufacturers sell to consumers by bragging about HP, just like on lawn mowers, or like amps on speakers or power tools. Another metric to look at is the CFM (cubic ft per minute) rating of the compressor, and match it to the tools you plan to use. (Apologies if I'm re-stating the obvious, here.)

Well, At the time I bought it, I didn't really think to look at CFM but now that I use more air tools than when I bought it... CFM Is Very important.

I just found a 60 gallon tank on Craigslist with a blown motor so I might buy that and fix it and just tank this compressor to my house. Maybe it would be easier to just go to Lowes or Tractor supply and get a 60 gallon with a decent motor!?

[Rodsmachineshop]

a real compressor that will hold up should be 5hp or higher and 220v to power all air tools how much was the one on craigslist and what hp was it

[CGCINC]

a real compressor that will hold up should be 5hp or higher and 220v to power all air tools how much was the one on craigslist and what hp was it

It didn't say the HP rating, just good 60 gallon tank with blown motor.
Lowes has a Kobalt 3.7running hp 60 gallon twin cylinder for $499 ???

I don't need a huge compressor, just something for sand blasting small parts and running a die grinder mostly.

[Rodsmachineshop]

would be fine for air tools but would not cut it for sand blasting . even my big compressor at my shop can not keep up sand blasting . sand blasting take a lot of cfm

[CGCINC]

All right... I'm gonna have to rethink my whole plan here!
My current compressor is like 3.7 CFM or something rediculous...

So is it the HP rating that increases the CFM rating or is it a cobination of tank size and HP?

[undercut]

All right... I'm gonna have to rethink my whole plan here!
My current compressor is like 3.7 CFM or something rediculous...

So is it the HP rating that increases the CFM rating or is it a cobination of tank size and HP?

You can only extract so much power from a 110v source. They usually max out around 4 CFM @ 90psi so one thing is only look for 220v units if you want more output.

When under 110v, they try to keep the amps 15 amps or lower which limits the amount of power you can extract from the wall. 220v circuits typically have higher max amps available and are double the volts so the CFMs you can get will be much higher.

Horsepower numbers can be manipulated so be careful looking at those numbers.

[KSmith]

I've been researching compressors also. I know the kobalt unit you are speaking of at Lowes. It is a single stage compressor 15 amp running, not sure what the start amp requirement is, but a 30 amp breaker should be enough. It is 220volt. It will run shop tools ok (except for impact wrench), but a sandblaster really needs a two stage compressor and 80 gallon tank, which gets up in the 1100 area at Lowes, HD. The horsepower like undercut says can be manipulated. I think the kobalt says 3.5 horse running, from memory. I never looked at horsepower that much. Instead, tank size, cfm, and price. All these kobalt, husky brands, and some others, are made by campbell-hausfeld from what I've read.

I don't know lowes policy, but Home Dep. will give you 10% discount for your veteran's service, and there may be some sales at all the stores for July 4.

ken

[geezer]

As far as the 499 special at lowes goes,,,I have one similar to that at my shop,,,couldn't resist the price,,,it's okay for running a plasma cutter and doing small sandblasting work in a desk top cabinet,,,not okay for real outdoor sandblasting,,,as Rod says,,you need at a minimum 5 real running HP not 5 peak HP as some advertise like the 499 special,,,If I was to up grade it would be to an 80 gal tank and either a 5 or 7.5 HP compressor with at least 20 CFM,,there is approx, 3 CFM for every HP,,,,not exact but close enough figuring when it comes time to buy,,,,and a CFM costs about 100 dollars per CFM,,,when you price out a compressor,,,I also have something similar to your little craftsmen,,,runs my plasma in my garage and a few small air tools,,,like nailers,staplers and that type,,,not good for automotive air tools or carbide die grinders

As a basic guide for buying,,,anything that has an 80 gal tank is probably okay,,,hard to find one with that tank size that doesn't have at least 5 honest hp in it.

[Rambozo]

I don't need a huge compressor, just something for sand blasting small parts and running a die grinder mostly.

Those are the two things that really tax a compressor.

There is no such thing as a free lunch. All the power comes from the motor, you want more power, you will need a bigger motor. The motor you have also looks like it might have an odd shaft for direct drive, and might not be simple to mount to a belt drive. You can run a pump that requires 3HP with a 1.5HP motor, but only if you cut the speed in half, so that's a zero sum game. Tank size is not really a big factor unless you have very sporadic air use. Then a large tank can help a small compressor "make do" for short periods of time. If your sandblaster uses 12 CFM, then you need a compressor that outputs at least 12 CFM @ sandblasting pressure in order to keep up. Otherwise you will have to stop and let the tank refill from time to time. However, if all you do is blast small parts from time to time, you would be ok with a smaller pump and a large tank. It all depends on how you use the air. Die grinders, actually any grinders, tend to run on and on, while things like impact wrenches run very short duty cycles. I have a friend who gets by with the smallest little motor and pump I've seen, but he has a couple of old compressor tanks plumbed into his system. Takes forever to fill (over 100 gal) but he can sandblast for a few minutes or run any tool, just not for long. For him it works fine. I have also worked in a lot of shops that had more than one compressor plumbed together. Running just one for most things, then running both for things like sandblasting. Single stage pumps generally give you higher CFM but lower pressure, while multi-stage units can achieve higher pressures. You can trade pressure for CFM a little bit if you run higher tank pressures than you need then regulate at the point of use. So instead of running the tank at 90 psi, for a tool, run it at 150 or 200 psi, then use a regulator at the tool to drop to 90 psi. CFM and pressure are like voltage and amperage. CFM = amps, pressure = voltage, it's a combination of both that do the work.

[zoama]

Find a 60 gallon 5hp electric compressor with a bad pump on craigs list. $50-$100 is a fair price/going rate... replace the pump with this 100% duty cycle one http://www.northerntool.com/shop/too..._290953_290953 .
Most of the motors will have a serpentine pulley on them... replace it with a 5" stamped steel, v-belt pulley. This setup will do what you want including sandblasting with a 1/8 nozzle. Can't beat it for $500

[Rambozo]

Horsepower numbers can be manipulated so be careful looking at those numbers.

These days HP numbers are almost worthless, (in the consumer space) check the volts and amps to compare.

[Rodsmachineshop]

I want this compressor 30cfm would be nice for all the sand blasting i do , really good price 1500.00 with free shipping, hey just had a brain fart lol forgot buy a refurbished compressor like half price with same warranty here a nice big one for under 500.00 http://www.northerntool.com/shop/too...duct_200396621

[CGCINC]

I want this compressor 30cfm would be nice for all the sand blasting i do , really good price 1500.00 with free shipping, hey just had a brain fart lol forgot buy a refurbished compressor like half price with same warranty here a nice big one for under 500.00 http://www.northerntool.com/shop/too...duct_200396621

DUDE!!!! What's the deal with those?! I wonder how reliable they would be?
Hmmmmmm..... That was a good find!!

[Rodsmachineshop]

just make sure if you buy one you get the 49 dollar extended warranty plan , not i buy a lot of refurbished stuff just bought a commercial airless sprayer last year a graco new was like 1500 refurbished like half price . worked and looked like new I figure if it has a warranty i dont care if its new or not oh and morgan and kolbalt are made the same place since use the same repair parts

[zoama]

DUDE!!!! What's the deal with those?! I wonder how reliable they would be?
Hmmmmmm..... That was a good find!!

That's a single stage pump on the $500 one and considerably less cfm than you'd get from the 2 stage northstar pump.

[Brian Ski]

a real compressor that will hold up should be 5hp or higher and 220v to power all air tools how much was the one on craigslist and what hp was it

Lots of good ideas... If you are upgrading now you know what under size is. From what I have learned cheap air tools use a lot more air. (HF for example) They do work well but use a lot of air. Sandblasters alone use a lot of air. What would you use one for??? Small parts or wheels??? Wheels will take a lot of air. You sure don't want to stop every minute for a minute or 2 to get the compressor to catch up.

220 is a must to start with. The 110 units are small. The motor and pump must balance... (if you are changing parts)Too small of a motor and the motor won't kick a pump under load. Even if it has a pressure relief. Plus it would use a lot more current.

BTW I would just get a new compressor... I normally don't look at HP I look at CFM at what PSI. Personally I would say 12 CFM would be a good starting point. Look at what tools you are planing on using like the sandblaster and see what CFM they take. Then bump it up a little.

Just a heads up. I would put the compressor in another area than where you work. Got a shed that you can put it in and run a line to the garage??? A lot less noisy. I have mine in the back of the small garage and a line running to the place where I do most of my work.

[Rodsmachineshop]

lay a cement slab like i did outside with a over head roof for rain better out side cooler for air compressor and most big compressors are noisy . tell you a funny story when i had my shop in palm springs my big compressor was in the customers bath room . made a lot of women scream when it fired off running in the bath room lol here a pic of the beast out back lol

[CGCINC]

Compressor on Craigslist.... Only bad is a 10gallon tank.

http://stlouis.craigslist.org/tls/3101319405.html