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Seems like Air Compressor time

H

Houndogforever

Hot Rolled
Joined
Oct 20, 2015
Location
Boring
So I have a small shop, currently running on a 30 year old 10hp, 2 stage cast iron pump air compressor.

The pump is making ugly noise.

I have a brother S700, A Fadal 3016 and a Hardinge conquest lathe. At most, there are two machines running at once.

The old ac would cycle about 4 times an hour.

I'm considering a Chicago Pneumatic QRS7.5HP-3
Chicago Pneumatic Quiet Rotary Screw 7.5HP Air Compressor - QRS7.5HP-3, Chicago Pneumatic: Auto Body Toolmart

Any opinions? Is this an appropriate sized unit?
Maintenance costs good or bad?

Thanks
 
I bought a 3 phase variable speed from Eaton Compressor several years ago. I'm running more machines, using a 7.5 hp. If they make a 5hp like that, and you can set up 3 phase, I think it would work very well. They are not top tier, but pretty decent. Or maybe look for a used vari-speed. My electrical cost for air stayed about the same as the on-off recip, and it's way quieter.
Good luck!
 
My experience with a small CP compressor was not great. Just slightly out of warranty the main shaft seal started leaking. Parts were available only as a kit with items not needed and very expensive. It was Eastern European built, I don’t recall what country.

Quincy would be a better choice IMO. Get hold of Rogers Machinery.
 
Our Ingersoll Rand stuff has been pretty low quality honestly.

We got a Quincy air dryer to replace the broken integrated one on our screw compressor and they are so far one brand that hasn't given us garbage.
 
A lot of the new stuff isnt that great. These days most stuff comes from china, or there have been corners cut everywhere to compete with chinese stuff. Might be worth taking a look inside your old one if it was meeting your requirements before. Could be just set of rod bearings and good to go again. Nothing wrong with old compressors. My compressor is a 1946.
 
Wish you were closer, we have a nice two stage compressor in our auction. We paid 2K+ probably not that long ago. Been a good one.
 
Houndogforever said:
So I have a small shop, currently running on a 30 year old 10hp, 2 stage cast iron pump air compressor.

The pump is making ugly noise.

I have a brother S700, A Fadal 3016 and a Hardinge conquest lathe. At most, there are two machines running at once.

The old ac would cycle about 4 times an hour.

Any opinions? Is this an appropriate sized unit?
Maintenance costs good or bad?
Click to expand...

On your Speedio, do you use air blast? How long between tool changes? Do you have a solenoid to shut off the spindle purge at idle? How big of a receiver?

I have a small 5hp Kaeser screw and the Speedio can keep it hopping if I’m running the right workload.
 
trochoidalpath said:
I have a small 5hp Kaeser screw and the Speedio can keep it hopping if I’m running the right workload.
Click to expand...

I have the Kaeser SX5 Air Center (integrated compressor, dryer, and tank). Running production, mine kicks off every 15 minutes or so, which is fine according to Kaeser.

So far, I am mostly happy with mine. Kaeser just opened up a Portland branch and they were nice to work with, but I was pissed about how cheap Kaeser went on some of the accessory fittings, as well as a 1/2" NTP filter. I played the bitching squeaky wheel and they made it all 100%.
 
One of the best compressors ever made was the Quincy QR25 series. I say was because the new ones might be made in China now. A used and freshened up 325 (5hp) would give 18 cfm and a 340 (10hp) about 30 cfm. Piston compressors, but I think it'd be the best choice. You probably want to just install one and go, not get into refurbishing. But if you did it, it would be the last compressor you'd ever have to purchase. There is evidence all over the 'net of guys 'fixing one up' with no regrets. including myself.
 
gkoenig said:
I have the Kaeser SX5 Air Center (integrated compressor, dryer, and tank). Running production, mine kicks off every 15 minutes or so, which is fine according to Kaeser.

So far, I am mostly happy with mine. Kaeser just opened up a Portland branch and they were nice to work with, but I was pissed about how cheap Kaeser went on some of the accessory fittings, as well as a 1/2" NTP filter. I played the bitching squeaky wheel and they made it all 100%.
Click to expand...

I would say I get a cycle every 10 minutes or so in normal operation, but I have a very small (30g) receiver. If I run an air blast and have lots of tool changes it definitely works hard enough to stay hot. I do plan on more aggressive oil changes and I check the sight glass pretty regularly for signs of water.

Kaeser around here (NorCal) was great to deal with. One minor headache getting things scheduled for install but we got it straightened out. I do agree that some of their fittings and whatnot sorta suck.

One thing I didn’t really think enough about was ventilation for the compressor. On a hot day, man, that thing gets HOT. I just opened up a chase for some extra ventilation, hopefully that helps.
 
There is a lot of talk about variable speed screw integrated compressors but not much on how much they cost. I suspect with my money it would be very hard to justify their cost over what I have now. So what do they cost?

I have an Ingersoll Rand 7.5hp compressor with the T30 pump, Baldor motor. 80 gal I think. And I think it's considered about 25 cfm. These are still available exactly the same as they have been making them for 40+ years. About $3200 now on Northern Tool site. I've seen them at tractor supply for like $2k but maybe that's not the case anymore. I also added a Hankison refrigerated dryer for $1000 or so. My number of machines is similar to the op's I think. This all just runs and runs. The only thing I had to do is to replace a capacitor in the motor.

My setup makes noise (I put it in a closet) and it makes heat. They all make about the same amount of heat.
 
Another vote for Eaton...
Replaced my old pump with their 10 HP 43 cfm v twin (yep really a v4 ..LOL )
Use it for sandblasting for the last 10 years,...

Regular oil changes never a problem.
 
Last edited:
MwTech Inc said:
Another vote for Eaton...
Replaced my old pump with their 10 HP 43 cfm v twin
Use it for sandblasting for the last 10 years,...

Regular oil changes never a problem.
Click to expand...

Thats actually a V4. My father in law has the same pump on an RK compressor. Same 10hp pump, but sold as 5hp compressor with 5hp motor. Turns over nice and slow (450rpm), real quiet.

Hard to beat a good quality pump like that. Does everything you want and its a lot cheaper and simpler then screw compressor.
 
Pete Deal said:
There is a lot of talk about variable speed screw integrated compressors but not much on how much they cost. I suspect with my money it would be very hard to justify their cost over what I have now. So what do they cost?……
Click to expand...

About 10 years ago I paid ~$70k for a 100HP variable speed Quincy.
 
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