Couple months ago I bought one of these:

http://tinyurl.com/yyqd

to replace my aging and no longer fully functional home-made air
compressor. (Link is to Sears, Craftsman 15 Gal 3HP air compressor.)

When I got it home and plugged it in, I couldn't believe my ears. The
thing sounds like a machine gun going off, continuously, until the tank
fills and the automatic shutoff cuts in, which seems like a half hour
but is probably closer to five minutes. (Try it in a newly sheetrocked
bedroom, with a texture hopper on the end of the hose, and nothing to
muffle the noise!)

My old compressor was almost whisper-quiet. I could use it any time of
day or night without waking the whole neighborhood, let alone members
of my household, since my shop is attached to my house, and I didn't
have to scream to make myself heard 10 feet away.

I'm ready to chuck this new one. Really. Just put a free sign on it and
wheel it out to the sidewalk. I'll eat the $200.

But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put dBs on
their specs anymore?

-Frank

--
fwarner1-at-franksknives-dot-com
Here's some of my work:
http://www.franksknives.com/

"Frank J Warner" wrote in message
news:030320051122460576%warnerf@veriSPAMMERSDIEzon .net...
Couple months ago I bought one of these:

http://tinyurl.com/yyqd

to replace my aging and no longer fully functional home-made air
compressor. (Link is to Sears, Craftsman 15 Gal 3HP air compressor.)

When I got it home and plugged it in, I couldn't believe my ears. The
thing sounds like a machine gun going off, continuously, until the tank
fills and the automatic shutoff cuts in, which seems like a half hour
but is probably closer to five minutes. (Try it in a newly sheetrocked
bedroom, with a texture hopper on the end of the hose, and nothing to
muffle the noise!)

My old compressor was almost whisper-quiet. I could use it any time of
day or night without waking the whole neighborhood, let alone members
of my household, since my shop is attached to my house, and I didn't
have to scream to make myself heard 10 feet away.

I'm ready to chuck this new one. Really. Just put a free sign on it and
wheel it out to the sidewalk. I'll eat the $200.

But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put dBs on
their specs anymore?


Many years ago I had a Hydrovane compressor installed at the facility where
I worked - expensive, but quiet and requiring very little maintenance.

Leon

But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put dBs on
their specs anymore?

-Frank


Don't throw it all the way away. Keep the air tank. It, anyway, should
be good for awhile, and should be fully warranted by Sears I mean K-Mart.

Next time ask *before* you buy! And don't buy anything unless you can hear
it run! (Yes, that rules out Homo Depo etc.)

I personally like Quincy compressors. They are made in the US, and they
are big and quiet, at least the big, quiet ones. I had a 1.5hp Sanborn
carpenter's rollaround and it sounded like an unmuffled WW1 fighter plane.
My Quincy hums along.

Start looking used in your area, for companies that are selling old ones.

Google for recent postings on what to look for.

GWE

On Thu, 03 Mar 2005 11:22:46 -0800, Frank J Warner
wrote:



But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put dBs on
their specs anymore?

Stay away from direct-drive and oil-less compressors. The quietest
units are belt drive with larger displacement and low pump RPM. They
also tend to deliver more CFM per HP, and last longer. They don't
always list pump RPM but you can judge by looking at (or measuring)
the pulleys.

Look at model 3Z170 at
http://www.grainger.com/Grainger/wwg...e&CatPage=1403

They used to offer a complete compressor using this pump. Note the
efficiency: 8.3 CFM at 100 PSI and 645 RPM from 2 HP, which can run
on 110V. These are very quiet pumps. I've seen them used in HVAC
systems in building that use pneumatic dampers.

I can relate!! I just got done reworking the exact same model
Craftsman unit after it blew the outlet tube gasket. After looking over
the internals, you probably should get a signed liability waiver from
anybody who gets your "free" on the sidewalk unit!! It wasn't my unit,
I was just reworking it for a neighbor.

I'd suggest getting a standard twin cylinder cast iron pump with a
normal 120/240 volt 2 hp motor. Grainger has nice Speedair for $419. #
4b227 at www.grainger.com

Frank J Warner wrote:
Couple months ago I bought one of these:

http://tinyurl.com/yyqd

to replace my aging and no longer fully functional home-made air
compressor. (Link is to Sears, Craftsman 15 Gal 3HP air compressor.)

When I got it home and plugged it in, I couldn't believe my ears. The
thing sounds like a machine gun going off, continuously, until the tank
fills and the automatic shutoff cuts in, which seems like a half hour
but is probably closer to five minutes. (Try it in a newly sheetrocked
bedroom, with a texture hopper on the end of the hose, and nothing to
muffle the noise!)

My old compressor was almost whisper-quiet. I could use it any time of
day or night without waking the whole neighborhood, let alone members
of my household, since my shop is attached to my house, and I didn't
have to scream to make myself heard 10 feet away.

I'm ready to chuck this new one. Really. Just put a free sign on it and
wheel it out to the sidewalk. I'll eat the $200.

But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put dBs on
their specs anymore?

-Frank

"Frank J Warner" wrote in message
news:030320051122460576%warnerf@veriSPAMMERSDIEzon .net...
Couple months ago I bought one of these:

http://tinyurl.com/yyqd

to replace my aging and no longer fully functional home-made air
compressor. (Link is to Sears, Craftsman 15 Gal 3HP air compressor.)

When I got it home and plugged it in, I couldn't believe my ears. The
thing sounds like a machine gun going off, continuously, until the tank
fills and the automatic shutoff cuts in, which seems like a half hour
but is probably closer to five minutes. (Try it in a newly sheetrocked
bedroom, with a texture hopper on the end of the hose, and nothing to
muffle the noise!)

My old compressor was almost whisper-quiet. I could use it any time of
day or night without waking the whole neighborhood, let alone members
of my household, since my shop is attached to my house, and I didn't
have to scream to make myself heard 10 feet away.

I'm ready to chuck this new one. Really. Just put a free sign on it and
wheel it out to the sidewalk. I'll eat the $200.

But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put dBs on
their specs anymore?

-Frank

--
fwarner1-at-franksknives-dot-com
Here's some of my work:
http://www.franksknives.com/


Should have done your research first, not after a purchase! Live & learn
huh?

Since you own a Quincy, I'm surprised that you remembered you had one. When
was the last time that you had to touch it?


"Grant Erwin" wrote in message
...

But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop. Any help and recommendations would be
appreciated. Do mfrs put dBs on
their specs anymore?

-Frank


Don't throw it all the way away. Keep the air tank. It, anyway, should
be good for awhile, and should be fully warranted by Sears I mean K-Mart.

Next time ask *before* you buy! And don't buy anything unless you can hear
it run! (Yes, that rules out Homo Depo etc.)

I personally like Quincy compressors. They are made in the US, and they
are big and quiet, at least the big, quiet ones. I had a 1.5hp Sanborn
carpenter's rollaround and it sounded like an unmuffled WW1 fighter plane.
My Quincy hums along.

Start looking used in your area, for companies that are selling old ones.

Google for recent postings on what to look for.

GWE

In article , Ignoramus2810
wrote:

I can only share my limited experience. I had a "harbor freight
pancake compressor" that was too loud.

Then I bought a Curtis compressor

http://igor.chudov.com/projects/CurtisCompressor/


this one is rather quiet, I can carry on a conversation in the garage
while it runs, and it can be barely heard if I am in any other part of
the house.

So, I would recommend a Curtis compressor if noise is your primary
concern. It is big and slow and well made.

Sure is a big puppy. I bet you don't wheel it around to the back yard
very often

Thanks for the recommendation, though.

-Frank

--
fwarner1-at-franksknives-dot-com
Here's some of my work:
http://www.franksknives.com/

In article t, RoyJ
wrote:

I can relate!! I just got done reworking the exact same model
Craftsman unit after it blew the outlet tube gasket. After looking over
the internals, you probably should get a signed liability waiver from
anybody who gets your "free" on the sidewalk unit!! It wasn't my unit,
I was just reworking it for a neighbor.

I'd suggest getting a standard twin cylinder cast iron pump with a
normal 120/240 volt 2 hp motor. Grainger has nice Speedair for $419. #
4b227 at www.grainger.com

Nice one. Looks a lot like my old one, which was kludged together from
spare parts by my father more than 30 years ago.

Thanks for the tip.

-Frank

--
fwarner1-at-franksknives-dot-com
Here's some of my work:
http://www.franksknives.com/

In article , Don Foreman
wrote:

On Thu, 03 Mar 2005 11:22:46 -0800, Frank J Warner
wrote:



But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put dBs on
their specs anymore?

Stay away from direct-drive and oil-less compressors. The quietest
units are belt drive with larger displacement and low pump RPM. They
also tend to deliver more CFM per HP, and last longer. They don't
always list pump RPM but you can judge by looking at (or measuring)
the pulleys.

Look at model 3Z170 at

http://www.grainger.com/Grainger/wwg...rCompatable=tr
ue&adobeCompatable=true&CatPage=1403

They used to offer a complete compressor using this pump. Note the
efficiency: 8.3 CFM at 100 PSI and 645 RPM from 2 HP, which can run
on 110V. These are very quiet pumps. I've seen them used in HVAC
systems in building that use pneumatic dampers.

Thanks, Don, for what to avoid and what to look for. I appreciate the
advice.

-Frank

--
fwarner1-at-franksknives-dot-com
Here's some of my work:
http://www.franksknives.com/

Frank J Warner wrote:
Couple months ago I bought one of these:

http://tinyurl.com/yyqd

to replace my aging and no longer fully functional home-made air
compressor. (Link is to Sears, Craftsman 15 Gal 3HP air compressor.)

When I got it home and plugged it in, I couldn't believe my ears. The
thing sounds like a machine gun going off, continuously, until the
tank
fills and the automatic shutoff cuts in, which seems like a half hour
but is probably closer to five minutes. (Try it in a newly
sheetrocked
bedroom, with a texture hopper on the end of the hose, and nothing to
muffle the noise!)

My old compressor was almost whisper-quiet. I could use it any time
of
day or night without waking the whole neighborhood, let alone members
of my household, since my shop is attached to my house, and I didn't
have to scream to make myself heard 10 feet away.

I'm ready to chuck this new one. Really. Just put a free sign on it
and
wheel it out to the sidewalk. I'll eat the $200.

But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put dBs on
their specs anymore?

-Frank

Homework, as others have said. Direct drive and oiless means that the
motor runs at twice the speed of a belt drive with more than twice the
noise. It usually means that the pump is also alloy and the piston
head is synthetic of some type. They can be handy for portable use
where you don't want oil spilling if the thing tips over in the back of
the van, just run the thing a LONG ways away from where you want to
work. Short drop cord, looong hose. There's also no problems with oil
contamination if you want to run a small paint gun. I have one of
these for that reason, you can cut the noise down a lot with some
judicious baffling around it, big cardboard boxes work OK as long as
you can keep it cool.

Mid-range is a belt drive with an oil-filled compressor, these have
alloy pumps with iron sleeves. I've also seen a direct drive with the
same features, I wasn't able to find a motor plate with the speed,
though.

High-end is the all-iron pump with belt drive, these tend to be on the
heavy end for portable operation, you aren't likely to sling one into
the back of a pickup single-handled.

The guy at the local Tool King says that the oilless Porter Cables are
pretty quiet, I didn't hear one run, though. Also, no feedback on
returns.

Sears is also probably NOT the place to go compressor shopping. I do
realize they are sometimes the only place in many miles for tool
shopping in some areas of the country.

Stan

Frank J Warner wrote:

Couple months ago I bought one of these:

http://tinyurl.com/yyqd

to replace my aging and no longer fully functional home-made air
compressor. (Link is to Sears, Craftsman 15 Gal 3HP air compressor.)

When I got it home and plugged it in, I couldn't believe my ears. The
thing sounds like a machine gun going off

Oh, come ON! It's not THAT loud! Maybe as loud as a big truck engine
with no
muffler, running at full throttle. Well, that's still TOO loud to
listen to for more
than a few minutes, even with ear protectors. Yes, I know, I had one, too.

I got a Quincy 2-cylinder compressor at the scrap yard, and did a little
repair
work (replaced filter, new oil, new safety relief) and it runs fine. It
is so
quiet that I hardly mind being near it WITHOUT ear protectors. But, I
usually wear them anyway, because what the compressor is running is
much louder than the compressor itself. This is their 1-2 HP pump,
that puts out a little over 6 CFM at 90 PSI with a 2 HP motor turning it
at 900 RPM.

Jon

Ignoramus2810 wrote:

On 3 Mar 2005 13:59:36 -0800, wrote:


Mid-range is a belt drive with an oil-filled compressor, these have
alloy pumps with iron sleeves. I've also seen a direct drive with the
same features, I wasn't able to find a motor plate with the speed,
though.

High-end is the all-iron pump with belt drive, these tend to be on the
heavy end for portable operation, you aren't likely to sling one into
the back of a pickup single-handled.



Stan, how can I tell a mid-range unit from a high-end unit by just
looking at them? I am curious if my Curtis compressor is high end or
midrange, according to your description.


If it has an oil pump (sure giveaway is if there is an oil pressure
gauge or oil filter) that is one big sign. Another is if it has unloaders
on the cylinder head. These are generally diaphragm-operated, and hold
the intake valves open while the motor is spinning up. Some also have
an interlock to unload the compressor if the oil pressure fails. Disc
valves are another high-end design feature, but it is pretty hard to tell
the valve type from the outside.

Jon

Ignoramus2810 wrote:
Thanks for enlightening me about CFM not being a function of only HP.

I was wondering, how come my HF pancake, which really is 2 HP,
delivers so much less air than my Curtis Toledo, which is only 3 HP.

Well, You really need to be on your toes. At a local place called Fleet
Farm, they have two belt drive models available that are very similar
looking. One is a 2HP the other a 3HP.

Of course, to Joe Blow, they might think that one has a "horse more"
than the other, but it isn't so.

One is MODEL 2HP, the other is MODEL 3HP. They both have exactly the
same motor, same amp draw, same pulleys and Pump. The model 3HP only
has a slightly larger tank and costs almost $100 more. near $100 for a
larger tank..........

The sales kid I hassled about it was sure that there was something
"inside" that made one a full horse power more... Go figure.

I have one of the noisiest peices of junk on the market too, as I
became too cheap to spend the $50 more dollars for the belt drive. Boy
am I Dumb !

Remember too, If your CFM is not adequate for the tool, a larger tank
doesn't necessarily mean much but for a few seconds anyhow.

Chris L

On Thu, 03 Mar 2005 21:17:27 GMT, the inscrutable "Tom Gardner"
spake:

Since you own a Quincy, I'm surprised that you remembered you had one. When
was the last time that you had to touch it?


"Grant Erwin" wrote in message
--snip--

HOPEFULLY, he changes the oil regularly.


================================================== ========
Save the ||| http://diversify.com
Endangered SKEETS! ||| Web Application Programming
================================================== ========

I'll second (or third? or 6th?) the Quincy recommendation - I paid $800 for
a rebuilt Quincy 5 HP setup around 15 years ago - 21 cfm at 160 psi with an
80 gallon (aprox) tank - great unit.

"Jon Elson" wrote in message
...


Frank J Warner wrote:

snip


one, too.

I got a Quincy 2-cylinder compressor at the scrap yard, and did a little
repair
work (replaced filter, new oil, new safety relief) and it runs fine. It
is so
quiet that I hardly mind being near it WITHOUT ear protectors. But, I
usually wear them anyway, because what the compressor is running is
much louder than the compressor itself. This is their 1-2 HP pump,
that puts out a little over 6 CFM at 90 PSI with a 2 HP motor turning it
at 900 RPM.

Jon

OK guys, 21 replies so far and no one has identified a specific,
off-the-shelf portable compressor that he considered to be ("whisper-")
"QUIET". Is one to conclude that despite 'doing their research' no one else
has been able to find one either and the only way to obtain one is to build
it up from components as described by several respondents ?

David Merrill

"Frank J Warner" wrote in message
news:030320051122460576%warnerf@veriSPAMMERSDIEzon .net...
Couple months ago I bought one of these:

http://tinyurl.com/yyqd

snip...

My old compressor was almost whisper-quiet. I could use it any time of
day or night without waking the whole neighborhood, let alone members
of my household, since my shop is attached to my house, and I didn't
have to scream to make myself heard 10 feet away.

snip...

But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put dBs on
their specs anymore?

How many times do you need to read Quincy? No compressor is
whisper quiet. Some are more tolerable than others. My Quincy is
in the same room, most of the noise comes from an add on check
valve that I installed. If you can pipe the air intake outside
and survive the consequences (heat and cold) the sound level drops
exponentially.

(top posted for your convenience)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Keep the whole world singing . . . .
DanG (remove the sevens)




"David Merrill" wrote in message
news:KXRVd.89030$tl3.76021@attbi_s02...
OK guys, 21 replies so far and no one has identified a specific,
off-the-shelf portable compressor that he considered to be
("whisper-")
"QUIET". Is one to conclude that despite 'doing their research'
no one else
has been able to find one either and the only way to obtain one
is to build
it up from components as described by several respondents ?

David Merrill

"Frank J Warner" wrote in
message
news:030320051122460576%warnerf@veriSPAMMERSDIEzon .net...
Couple months ago I bought one of these:

http://tinyurl.com/yyqd

snip...

My old compressor was almost whisper-quiet. I could use it any
time of
day or night without waking the whole neighborhood, let alone
members
of my household, since my shop is attached to my house, and I
didn't
have to scream to make myself heard 10 feet away.

snip...

But I need ideas for a replacement that doesn't sound like a
friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put
dBs on
their specs anymore?

On Thu, 3 Mar 2005 23:27:30 -0600, "DanG" wrote:

(Top posted for your convenience....)

Ya won't go wrong with Quincy, but they are by no means the only good
show in town. Ingersoll and Speedaire also make good compressors.
The 3-cylinder 2-HP Speedaire I've seen in a number of installations,
plugging away at 645 RPM, produced a quiet lubba-dubba sound. I've
heard noisier home-laundry washing machines. Noisy compressors are
not acceptable in small office buildings.

I have a 5-HP two-stage IMC ripoff of the Ingersoll T-29 that is not a
bit hard to live with. A Solberg muffler on the intake helps a lot.
I wouldn't call it whisper quiet, but it's low and throaty, less
annoying than the whine of the integral fan in the 5 HP motor I use as
a phase converter.

As DanG said, no compressor is whisper quiet. A big part of having
it easy to live with is to have the noise it does make be
predominately low frequency. That means low speed, with no metallic
rattles or resonances.

You seem to want portability/mobility. That creates a tradeoff
situation because low speed means larger displacement (and weight, and
size), and freedom from rattles and resonances implies either very
good design, some massiveness or both.

My approach to your problem would be to find the lowest-speed
compressor that meets your size/weight/mobility/air-delivery needs
and then start killing rattles and resonances. First, tighten or
weld anything that rattles. Then brace things that are obviously
vibrating a lot. Then add resonance-killers (bits of solder or lead
strategically placed at nodes by trial and error) until the remaining
noise is low-freq lubba-dubba that is not offensive. You can find
nodes by feel: just run your hands over the machine. Nodes tickle
your fingertips. Just a wee bit of lead crimped or epoxied at a node
can quash a resonance very effectively.


How many times do you need to read Quincy? No compressor is
whisper quiet. Some are more tolerable than others. My Quincy is
in the same room, most of the noise comes from an add on check
valve that I installed. If you can pipe the air intake outside
and survive the consequences (heat and cold) the sound level drops
exponentially.

HOPEFULLY, he changes the oil regularly.



Oil?

One other thought... check the pawn shops. A student of mine got a 2 HP
230 volt, belt drive, cast iron oil lubed compressor unit.... with a
good sized tank. Not light, takes two strong people to load... paid
$150. He did need to spend $9 for a new air filter. Works great..
B.G..

On Fri, 04 Mar 2005 18:09:40 GMT, the inscrutable "Tom Gardner"
spake:

HOPEFULLY, he changes the oil regularly.

Oil?

Either you're using one of those noisemaking Chiwanese oilless bastids
or you forgot that a precision machine needs regular maintenance.
Egad, man. Where's your common sense? (Still hopin' you were jokin'.)


================================================== ========
Save the ||| http://diversify.com
Endangered SKEETS! ||| Web Application Programming
================================================== ========

Ignoramus2810 wrote:
On 3 Mar 2005 13:59:36 -0800,
wrote:
Mid-range is a belt drive with an oil-filled compressor, these have
alloy pumps with iron sleeves. I've also seen a direct drive with
the
same features, I wasn't able to find a motor plate with the speed,
though.

High-end is the all-iron pump with belt drive, these tend to be on
the
heavy end for portable operation, you aren't likely to sling one
into
the back of a pickup single-handled.

Stan, how can I tell a mid-range unit from a high-end unit by just
looking at them? I am curious if my Curtis compressor is high end or
midrange, according to your description.

i
Magnet maybe? The ones with alloy crankcases and iron sleeves are
pretty shiny, too, quite evident that they're cast out of aluminum.
Cast iron pumps look like, well, cast iron. Hefty, too.

Stan

HOPEFULLY, he changes the oil regularly.

Oil?

Either you're using one of those noisemaking Chiwanese oilless bastids
or you forgot that a precision machine needs regular maintenance.
Egad, man. Where's your common sense? (Still hopin' you were jokin'.)

So, just where does the oil go into my Quincys...If I can find the three of
them, I forget where they are, I COULD follow the pipes I guess.

Don Foreman wrote:
... Ingersoll and Speedaire also make good compressors.
....

Make that " ... make SOME good compressors.". Not all of them are good.
I have an IR that is very noisy. It is oiled and belt-driven, but a
home-shop model. I forget the model, but it's 1 1/2 hp (?), 20 gal
tank. It does have an aluminum pump, so that might be the real difference.

Bob

In article ,
Ignoramus17955 wrote:

[...]

Oh, I see. Mine is all iron. Which makes me wonder, iron is cheaper
than aluminum, how come lower priced models are made of higher priced
metal.

i

Probably because it's faster & cheaper to cast & machine. When
you're making a million of 'em...

--
B.B. --I am not a goat! thegoat4 at airmail dot net
http://web2.airmail.net/thegoat4/

"Grant Erwin" wrote in message
...

But I need ideas for a replacement that doesn't sound like a friggin'
50-Cal going off in my workshop.

Any help and recommendations would be appreciated. Do mfrs put dBs on
their specs anymore?

-Frank


Don't throw it all the way away. Keep the air tank. It, anyway, should
be good for awhile, and should be fully warranted by Sears I mean K-Mart.

Next time ask *before* you buy! And don't buy anything unless you can hear
it run! (Yes, that rules out Homo Depo etc.)

I personally like Quincy compressors. They are made in the US, and they
are big and quiet, at least the big, quiet ones. I had a 1.5hp Sanborn
carpenter's rollaround and it sounded like an unmuffled WW1 fighter plane.
My Quincy hums along.


I don't know, my 20hp Quincy is rather loud (it is mainly intake noise
though)

William...

Start looking used in your area, for companies that are selling old ones.

Google for recent postings on what to look for.

GWE

"Ignoramus2810" wrote in message
...
On Thu, 03 Mar 2005 17:08:32 -0600, Jon Elson
wrote:


Ignoramus2810 wrote:

On 3 Mar 2005 13:59:36 -0800,
wrote:


Mid-range is a belt drive with an oil-filled compressor, these have
alloy pumps with iron sleeves. I've also seen a direct drive with the
same features, I wasn't able to find a motor plate with the speed,
though.

High-end is the all-iron pump with belt drive, these tend to be on the
heavy end for portable operation, you aren't likely to sling one into
the back of a pickup single-handled.



Stan, how can I tell a mid-range unit from a high-end unit by just
looking at them? I am curious if my Curtis compressor is high end or
midrange, according to your description.


If it has an oil pump (sure giveaway is if there is an oil pressure
gauge or oil filter) that is one big sign.

I do not think that mine has that.

Another is if it has unloaders on the cylinder head.

Yes, I have unloaders for easy start.

Not the type he is describing
here is a "high-end" model pump
http://quincycompressor.com/products...qr25/index.htm

William...



These are generally diaphragm-operated, and hold the intake valves
open while the motor is spinning up. Some also have an interlock to
unload the compressor if the oil pressure fails. Disc valves are
another high-end design feature, but it is pretty hard to tell the
valve type from the outside.

Thank you! By the way, the whole pump seems to be made from iron.

i