..There are six things you need to know about compressors:
The maximum PRESSURE that it develops, the rated VOLUME it
can deliver, the amount of compressed air it can STORE, how
LONG the motor can run (which is also known as "duty
cycle"), how much electrical POWER it's going to take to
run, and how much NOISE it's going to make....
Continued: http://atu.ca/AirCompressors
"Proctologically Violated©®" wrote:
>
> "Michael A. Terrell" <[email protected]> wrote in message
> news:[email protected]...
> >
> > "Proctologically Violated©®" wrote:
> >>
> >> log 2 = .3 (the definition of a decibel is the 10 x log of acoustical
> >> energy, iirc).
> >>
> >> The decibel is not "hard" physics, like energy, absolute temp, etc, but
> >> rather a description of how we perceive acoustical energy.
> >> And is only approximate at that, with freq, loudness itself, spatial
> >> considerations, etc.
> >>
> >> Play one trumpet at 60 db. Play second trumpet at 60 db. Play both
> >> trumpets together, you "hear" 63 db.
> >> The acoustical energy has indeed doubled, but not the perceived loudness.
> >> Or so I lernt.
> >
> >
> > Only if both are exactly in phase. Anything less, and the increase
> > is under 3 dB. If they are exactly 180 degrees out of phase and at the
> > same level, they cancel each other.
>
> There ya go!
> So just get two identical compressors, delay the start of the second one by
> 1/2 wavelength, and you will have zero db air!!
Only if they are exactly identical, to the last atom, and you are
positioned at the exact spot where full cancellation takes place.
Otherwise, you would get some reduction. Try it with speakers some
time. If they are in phase and facing each other you can find dead
spots where you can't hear either speaker. I did this for a football
stadium. The players couldn't hear the announcer over the speakers, and
you could use a live microphone anywhere between the goal posts.
--
http://improve-usenet.org/index.html
aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
On Dec 11, 10:38=A0pm, "Up North" <[email protected]> wrote:
> Admittedly, my post does not dovetail with this thread since you're
> talking electric motor driven compressors. =A0However, I simply must
> brag and chortle about my air cooled DIESEL milsurp air compressor.
> Apparently it was designed to air up tires on jets. =A0It's similar to
> the "wheel barrow" compressors that carpenters use. =A0It has a single
> tank and a two stage compressor (175 psi!) compressor, belt driven by
> a Yanmar 3 hp, fuel sipping, air cooled engine. =A0It is well balanced
> and light weight. =A0It CHURNS out air. =A0It starts from a battery or
> with a rope. =A0I swoon over its efficiency, reliability, and fuel
> economy. =A0In fact, I think I'll go give it a hug right now. =A0Vernon
>
> Now Vernon, you weren't over there squeezing her jugs now were you?
Up North. Noooo. But I was tweaking her nipples! V
On Dec 12, 8:39=A0am, Smitty Two <[email protected]> wrote:
> In article <[email protected]>,
> =A0Mike Marlow <[email protected]> wrote:
>
> > For most people participating in threads like
> > this, oilless translates directly to the cheap shitty stuff.
>
> Yep. That's why every time someoone brings it up, I respond. My
> compressor is oilless. It was not cheap, it is not shitty, and it is
> about as quiet as a compressor can be.
>
> My argument isn't so much about compressors as with the
> correlation/causation confusion that most people are too stupid to
> understand even if you 'splain it to 'em with a sledge hammer.
>
> So instead of saying, "whatever you do, don't buy an oilless," I'd be
> happier if people would say "whatever you do, don't buy a cheap, shitty
> compressor."
And that advice would apply rather you are buying an oilless or not.
While a slight amount of oil had very little effect on solvent based
paints, that is not the case with today's water based epoxy and latex
paints.
On Sat, 13 Dec 2008 12:49:57 -0600, Greg O cast forth these pearls of
wisdom...:
>
> 5HP on a 120 volt circuit? Somebody is pulling your leg, but looks like you
> realize it!
> I bought a Porter Cable 7HP, (sure you betcha), 60 gallon tank compressor a
> few years ago. Motor amps tell me that it is closer to 3 HP. It does all I
> want it to do. I can run any air drill, DA sander I have, and it just about
> keeps up. And what I mean by that is for a home, weekend warrior shop it is
> just fine. I don't drill or sand continuously for hours on end. By the time
> the tank starts to run a bit low I am ready for a 30 second break, and the
> the compressor catches up again. Really I don't even notice any short
> comings. If you planed on running a sander continuously with no break at all
> it will not keep up.
> In my opinion, most any one man home shop can get along nicely with 10 CFM
> at 90 PSI.
> Greg
I was pretty much with you Greg, until that last statement. In fact - I
might still be with you in light of that last statement, but the DA issue
kinda rubs a bit. If a fellow is going to expect to do a fair amount of
work with a DA, then 12 is probably a betterr bet for him. It's easy for a
DA to overwhelm a compressor and it's even easier to be laid right into a
DA for long, continuous times.
--
-Mike-
[email protected]
On Fri, 12 Dec 2008 13:12:24 -0500, Ed Edelenbos cast forth these pearls of
wisdom...:
> "Lew Hodgett" <[email protected]> wrote in message
> news:[email protected]...
>> "Chris Friesen" wrote:
>>
>>> If I were ever to buy a stationary compressor, it would be one that you
>>> wouldn't be able to run on a 120V circuit. A real 5HP one sounds about
>>> right...30A at 240V.
>>
>> Make that a 5HP, cap start, cap run motor, driving a 2 stage compressor
>> with an 80 gal vertical receiver and you will have gone about as far as
>> you can go.
>>
>> BTW, you will need a 240V, 2P-40A CB to handle the inrush.
>>
>> Lew
>
> This just makes me wonder what the application is. What sort of shop would
> require a machine like that? I guess a production shop (or a shop where you
> were doing auto mechanic work) would need a large compressor but I think
> that would be overkill for most home woodworking workshops. What sort of
> tools do any of you using compressors use?
>
> Ed
Painting, especially if you are using HVLP equipment, air sanders (DA's),
and some other air tools that are always on - as contrasted to the
infrequent on state of say, an impact gun, or a nailer. For most home
workshops, a little 30 gallon compressor with a couple horse motor is
usually fine.
Whatever you do - think about how you will use a compressor. Look at the
tools that you'll be using and find out the SCFM requirement of those
tools. Add 50% - because the guy in you will most certainly buy more stuff
down the road that requires more capacity from your compressor. Buy enough
compressor to supply the most demanding tools, plus some.
Don't let anyone fool you - it's not about horsepower and all that other
stuff people like to talk about. It's about SCFM - the ability of the
compressor to deliver air. That is hands-down your primary consideration
when looking at compressors.
Your secondary considerations are capacity (tank size) and duty cycle. You
are not likely to use your tools in a home shop enough to really worry
about duty cycle, but a good compressor will be rated for continuous duty.
In tanks sizes - it's kind of like some other things - bigger is better.
Smaller can get by, but bigger is better.
--
-Mike-
[email protected]
On Thu, 11 Dec 2008 18:21:06 -0800 (PST), BobR cast forth these pearls of
wisdom...:
> On Dec 10, 10:12 pm, Tony Hwang <[email protected]> wrote:
>> DC wrote:
>>> ..There are six things you need to know about compressors:
>>> The maximum PRESSURE that it develops, the rated VOLUME it
>>> can deliver, the amount of compressed air it can STORE, how
>>> LONG the motor can run (which is also known as "duty
>>> cycle"), how much electrical POWER it's going to take to
>>> run, and how much NOISE it's going to make....
>>
>>> Continued:http://atu.ca/AirCompressors
>>
>> Hi,
>> Also whether compressor is lubricated or not.
>> Never get non-lubricated one. I have a Campbell Hauser
>> Extreme duty belt driven compressor which can be powered by either
>> 120V or 208V. I am running it on 120V plugged into regular wall outlet
>> in the garage. For what I do it is adequate. It can even blow sprinklers
>> in the fall.
>
> If you are talking about using the compressor only for power tools and
> general use, I agree with the lubricated vs non-lubricated. If you
> plan to use that compressor for painting, I would recommend the non-
> lubricated. You don't want oil in the lines when painting.
Not true. A lubricated compressor is better for all wood shop uses than an
oilless compressor. The oilless models are throw away, light duty, short
lived compressors, and they make a ton of noise. Whether the compressor is
lubricated with oil or not has no bearing on its use for painting. I think
what you were thinking of was whether to use a line oiler. Certainly, if
you're going to paint with that system, do not install a line oiler.
Simply oil your tools through the chuck, as needed.
--
-Mike-
[email protected]
On Thu, 11 Dec 2008 22:10:59 -0800, Smitty Two cast forth these pearls of
wisdom...:
>>> If you are talking about using the compressor only for power tools and
>>> general use, I agree with the lubricated vs non-lubricated. If you
>>> plan to use that compressor for painting, I would recommend the non-
>>> lubricated. You don't want oil in the lines when painting.
>>
>> Not true. A lubricated compressor is better for all wood shop uses than an
>> oilless compressor. The oilless models are throw away, light duty, short
>> lived compressors, and they make a ton of noise. Whether the compressor is
>> lubricated with oil or not has no bearing on its use for painting. I think
>> what you were thinking of was whether to use a line oiler. Certainly, if
>> you're going to paint with that system, do not install a line oiler.
>> Simply oil your tools through the chuck, as needed.
>
> Oh boy, here you go again, pushing my buttons. I've expounded at some
> length about this in the past, but I'll be brief tonight. Cheap, shitty
> compressors are oilless. However, that does not mean that all oilless
> compressors are cheap and shitty. Mine is very, very good, and I sure as
> hell don't want oil in my air most of the time. When I do, I can add it
> myself. There's plenty of oil in your average oil-lubricated compressor
> to destroy a paint job.
Do you paint? I do. Never had an oil infiltration problem that was caused
by the lubricant from my compressor. If you're encountering that, you've
got compressor problems. For most people participating in threads like
this, oilless translates directly to the cheap shitty stuff.
--
-Mike-
[email protected]
Air compressors have losses . V belts are a waste , not necessary .
I just bought 6 HarborFright 40400 DIRECT drive ( 8 gallon tank)
for
$100 each .
I can series them , output of one could enter the crankcase of the
next
stage then directed to the head intake valves .....IF the seals would
hold ..
But 1 stage is efficient if PSI is below about 60 ( 4:1
ratio ) ...
At 110 PSI , its a big loss to have only one stage .
Auto a/c is over 10:1 on a hot day and condenser is not gulping 50
MPH
air .
Or i could parallel 4 , staggering the start up by 5 seconds .
This is more efficient than a $600 , 5 H.P. , 12 CFM belt drive ,
I could also put a 6004 2-RS ball bearing on crankshaft ..
I needed these for the H.F. 4 amp PLASMA cutter .
at half the price ( $700 ) of competition , i bought 2 . I also
bought 50 Zirconium/halfnium electrodes ( abt $250 ).
I can reshape the copper cups , easily .
This 40 amp Plasma uses a 4 transistor "H" bridge ... BAD idea ,
but as i said , i got a low price on the cutter ..
Modern circuitry uses only 1 or 2 transistors a single primary
winding ,
driving it in one direction , NOT a half bridge , just a simple one
sided
forward converter . This way transistors saturate the core , then
hit it again
saturate the core etc etc . This is enhernetly safer than the
complicated
current mode chips driving alternate NPN's . But i could always
take out
the extra transistors , save them for a rainy day , use only 2 for
even higher
output . 2 NPN IGBT's inparallel will drive MORE , than the lossy H
bridge .
Plasma uses a mcu AT91xxxx . waste of mcu ....
Torch electrode is negative . copper cup with .8 mm hole is
POSITVE , but
has a huge choke of 2.2 mil henries . Theres no capacitors
in the circuit , so the pulsating D.C. is limted by the choke and is
called
Pilot arc ( aka starting arc ).
The zirconium electrode is pulled away from copper cup as soon
as circuit measures current in the ground cable .
Small cables used here cause plasma uses 90 vdc at
low amps ( 10 amps can cut 1/8" steel )
pull torch away from work , and pilot arc starts again .
NO MOVING PARTs , nothing to wear out ,
except chrome plated tiny electrodes at $6 each .
Lincoln electric inc' said they cut 1/2" plate
and got 450 feet of cut with each electrode .
Plasma cuts fast narrow and encredibly clean.
I bought 3 H.F. Stick/T.I.G. inverter welders ( red box ),
i call it "e-welder" . Buzz boxes can't limit the current , set at
100 amps
they go to 200 amps til you can pull it free !
But e-welder can "fold back current " instantly . And it will go
out , if
you pull the electrode away , even to an 1/4" !
Buzz box just increases the voltage !
All my friends are raving about it . im doin diagrams on it .
It will power a Wire Feed . It needs circuit mods to hold D.C
Voltage constant .
It does not use mcu's , only a current mode controller and an
IGBT half bridge , . dumb ! MJE13007's cost $0.12 each and are
lower
loss when enough are paralled to the same amps as the IGBT's ...
Insulated Gate Bipolar Transistor is much higher loss , much higher
cost ,
passing 20 amps ,
IGBT have about 2.5 to 3.5 volts of LOSS ,
MJE13007's in parallel can do 0.5 vdc !
paralleld Schottkies can use current sensing to shut them down on
over heat . It has a tiny 60hz transformer to power CONTROL ckt .
Ill replace it w/ 80 to 260 VAC switcher , then add big
Caps and Diodes to MOD it to run on 110vac . Now its 220vac
ONLY .
They use a current mode controller chip and 4 surface mnt NPN's to
drive
yet another transformer to drive the IGBT gates ! waste of
circuitry !
Even if transformer doesnt have a winding to drive the bases , you
can add
a tiny toroid in output , as all C.F. flourescents have ,..
ALL cost effective IBMPC power supplies saturate the transformer ,
to
save a chip . But output has a chip that sends back a signal to
control the
MJE13007 , ussualy just to shut it dn prematurely , then allow it to
self start
into the next cycle ...
One MJE13007 and a tiny transformer makes 450 watts ! That was my
plan til HF
inverter showed up . I bought 20 PC power supplies from MCM and
started
figuring how to parallel them to weld with .
Inverters can run 100% duty cycle with low cost MODs .
Plasma cut be MODed to do 40 amps at 100% duty cycle .
e-welder can do 130 amps at 100% .
The Ferrite transformer is the limit .
It stops working at a very low "Curie" temperature .
simply force a little air over it ! e-welder has fan far away ..
I also got 6 HF 13HP gas engines , i will MOD to Atkison cycle ,
since the CAM allready has centrifugal advance ...
I got 2 , 13hp , 5500 WATT gas GenSets .. they use brushes in
alternator .
Ill be busy for months modifying this stuff !
BTW WiFi will be your new cell phone . The world will link up
WiFi
and a new GUI method of communication . No voice , nor text , you
will
have 8 buttons that send ICONs and Thumbnails and European traffic
warnings
that will be understood by all humans , no need to translate ...
The B.W. is very wide . You can vu a Hollywood movie on WiFi , and
with a dish
you can link at over 80 miles . The world will simply store and
forward in
a cooperative way .. Also the new pocket PC is a GP2X game box ,
w/
80 GB HDD .. some one hooked a WiFi to GP2X .
Much easier to do in Linux ,, than in WXP op systems
[email protected] from Guadalajara MX ..
On Thu, 11 Dec 2008 22:31:16 -0800, Smitty Two cast forth these pearls of
wisdom...:
> In article <[email protected]>,
> "Steve Barker DLT" <[email protected]> wrote:
>
>> you can bet large (and small) body shops don't use oil-less compressors.
>> The good old fashioned kind been working fine painting cars for a hundred
>> years now.
>>
>
> You can bet anything you want. I rarely see a paint job that isn't
> orange-peeled, so my guess is that painters as a lot are as incompetent
> at their so-called profession as any other group. But I imagine that any
> decent paint shop would have some pretty good filters on the air, no
> matter how they compress it.
>
Water traps mostly. The previous poster is correct though, with respect to
the type of compressor you will find in body shops.
--
-Mike-
[email protected]
On Sat, 13 Dec 2008 14:21:36 -0500, john cast forth these pearls of
wisdom...:
>
>
> If you paint and don't want to have any problems, get a bottle of dry
> Nitrogen and a good two stage regulator. NO oil No water that you can
> blame as to your quality of the paint job. :)
>
>
> John
Whoa - just a minute there mister. That last sentence does not quite sit
right. You might want to rethink that...
--
-Mike-
[email protected]
"James Sweet" <[email protected]> wrote in message
news:[email protected]...
> >
> General rule for air compressors is buy the biggest one you can afford,
> because you always seem to need more air later than you thought. Mine is a
> "5HP" (yeah right) oiled reciprocating compressor which is just *barely*
> adequate to run my abrasive blasting cabinet. Had I know I'd get one of
> those, I'd have bought a larger compressor in the first place, though what
> I have is about as big as you can run from a 120V circuit.
5HP on a 120 volt circuit? Somebody is pulling your leg, but looks like you
realize it!
I bought a Porter Cable 7HP, (sure you betcha), 60 gallon tank compressor a
few years ago. Motor amps tell me that it is closer to 3 HP. It does all I
want it to do. I can run any air drill, DA sander I have, and it just about
keeps up. And what I mean by that is for a home, weekend warrior shop it is
just fine. I don't drill or sand continuously for hours on end. By the time
the tank starts to run a bit low I am ready for a 30 second break, and the
the compressor catches up again. Really I don't even notice any short
comings. If you planed on running a sander continuously with no break at all
it will not keep up.
In my opinion, most any one man home shop can get along nicely with 10 CFM
at 90 PSI.
Greg
On Dec 10, 10:12=A0pm, Tony Hwang <[email protected]> wrote:
> DC wrote:
> > ..There are six things you need to know about compressors:
> > =A0The maximum PRESSURE that it develops, the rated VOLUME it
> > can deliver, the amount of compressed air it can STORE, how
> > LONG the motor can run (which is also known as "duty
> > cycle"), how much electrical POWER it's going to take to
> > run, and how much NOISE it's going to make....
>
> > Continued:http://atu.ca/AirCompressors
>
> Hi,
> Also whether compressor is lubricated or not.
> Never get non-lubricated one. I have a Campbell Hauser
> Extreme duty belt driven compressor which can be powered by either
> 120V or 208V. I am running it on 120V plugged into regular wall outlet
> in the garage. For what I do it is adequate. It can even blow sprinklers
> in the fall.
If you are talking about using the compressor only for power tools and
general use, I agree with the lubricated vs non-lubricated. If you
plan to use that compressor for painting, I would recommend the non-
lubricated. You don't want oil in the lines when painting.
"Smitty Two" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>,
> Mike Marlow <[email protected]> wrote:
>
>> For most people participating in threads like
>> this, oilless translates directly to the cheap shitty stuff.
>
> Yep. That's why every time someoone brings it up, I respond. My
> compressor is oilless. It was not cheap, it is not shitty, and it is
> about as quiet as a compressor can be.
What brand/model compressor is this? Price?
--
Mr. PV'd
Mae West (yer fav Congressman) to the Gangster (yer fav Lobbyist):
Hey, Big Boy, is that a wad (of cash) in yer pocket, or are you just
glad to see me??
>
> My argument isn't so much about compressors as with the
> correlation/causation confusion that most people are too stupid to
> understand even if you 'splain it to 'em with a sledge hammer.
>
> So instead of saying, "whatever you do, don't buy an oilless," I'd be
> happier if people would say "whatever you do, don't buy a cheap, shitty
> compressor."
"DC" <[email protected]> wrote in message
news:[email protected]...
> ..There are six things you need to know about compressors:
> The maximum PRESSURE that it develops, the rated VOLUME it
> can deliver, the amount of compressed air it can STORE, how
> LONG the motor can run (which is also known as "duty
> cycle"), how much electrical POWER it's going to take to
> run, and how much NOISE it's going to make....
>
> Continued: http://atu.ca/AirCompressors
>
Not a bad article, if you don't mind the tone of the Very Authoritative
Home-moaner.
But as far as size goes, buying small-ish isn't necessarily a bad thing, as
compressors are simply additive. Three small compressors should be exactly
equivalent to one big one, with a few advantages:
1. You now have inherent staging, with all of its advantages: reduced
electrical surge/"demand"; greater economy at low demand. Would proly need
better pressure regulators in each unit, tho, as those in small units are
usually not the best.
2. Likely quieter. Doubling the number of sources of the same noise only
adds 3 db, vs. perhaps a much greater decibel increase of a larger unit.
ie, two trumpets each at the same db is not as loud as one trumpet played
more forcefully.
3. Smaller = portable, if nec.
4. May be easier to fit numerous smaller compressors in nooks and crannies.
5. Repair is easier, due to redundancy -- you won't be totally out of air.
And Quincy's are nice, but I could proly buy a whole new small HD/c.h. for
the price of one Q repair.
6. One can be set up for special apps, like painting, etc.
Proly some other advantages, as well.
HD/campbell hausefeld has a very nice upright 30 gal compressor, dual
voltage motor, belt driven cast iron compressor w/oil, sight glass, wheels,
VERY quiet. I would buy multiples of these in a minute.
Also, in many cases, larger resevoir volume is all that is needed, not a
bigger compressor. I have numerous small makeup tanks for about 70 gals,
works great with one small compressor.
Would work even for air tools, depending on how much you use them vs. your
total gallons.
--
Mr. PV'd
Mae West (yer fav Congressman) to the Gangster (yer fav Lobbyist):
Hey, Big Boy, is that a wad (of cash) in yer pocket, or are you just
glad to see me??
--
Mr. PV'd
Mae West (yer fav Congressman) to the Gangster (yer fav Lobbyist):
Hey, Big Boy, is that a wad (of cash) in yer pocket, or are you just
glad to see me??
"Greg O" <[email protected]> wrote in message
news:[email protected]...
> "Proctologically Violated©®" <[email protected]> wrote in message
> news:[email protected]...
>>
>>
>> 2. Likely quieter. Doubling the number of sources of the same noise
>> only adds 3 db, vs. perhaps a much greater decibel increase of a larger
>> unit. ie, two trumpets each at the same db is not as loud as one trumpet
>> played more forcefully.
>>
>>
>
> I will argue that point!
> Seems to me that the larger HP cast iron pump compressors are very quiet,
> certainly when compared to a 1HP oil less unit. My cheapy 7HP, (really
> about 3HP) Porter Cable is quieter than the 1-1/2 Craftsman it replaced.
> Much quieter than the oil less models we have at my job. Some of the 5HP
> cast iron compressors are strangely quiet. Low RPM pump and motor reduce
> noise a bunch, but at a premium price.
Yeah, I basically agree with that, just my point was that a quiet small
compressor, doubled or tripled, will not nec. be noisier than a single large
compressor.
As I mentioned, the HD/c.h. 30 gal are amazingly quiet, numerous people
telling me they are the quietest units they've heard. About $400. Same
compressor heads found on SpeedAires. campbell hausefeld make the compressor
heads for a number of brands.
Also, altho I agree with the bogus hp ratings, the fact that you measured a
given amps whilst running still may not reflect the *capacity* of the motor.
iow, the motor may still be capable of driving a larger compressor head.
iow, that compressor head may only require 3 hp.
Note also, that on the HD compressor head, the fan belt shroud is designed
to funnel air across the head, which is a nice touch. ie, the pulley acts
as a lite fan.
--
Mr. PV'd
Mae West (yer fav Congressman) to the Gangster (yer fav Lobbyist):
Hey, Big Boy, is that a wad (of cash) in yer pocket, or are you just
glad to see me??
> Greg
"Leon" <[email protected]> wrote in message
news:[email protected]...
>
> "Proctologically Violated©®" <[email protected]> wrote in message
> news:[email protected]...
> Snip
>
>>>
>>
>> Not a bad article, if you don't mind the tone of the Very Authoritative
>> Home-moaner.
>>
>> But as far as size goes, buying small-ish isn't necessarily a bad thing,
>> as compressors are simply additive. Three small compressors should be
>> exactly equivalent to one big one, with a few advantages:
>>
>> 1. You now have inherent staging, with all of its advantages: reduced
>> electrical surge/"demand"; greater economy at low demand. Would proly
>> need better pressure regulators in each unit, tho, as those in small
>> units are usually not the best.
>
> You really dont want all three coming on at the same time or running at
> the same time either. A breaker could be blown very easily with 2 or more
> running at the same time not to mention if 2 came on at the same time.
>
>
>>
>> 2. Likely quieter. Doubling the number of sources of the same noise
>> only adds 3 db, vs. perhaps a much greater decibel increase of a larger
>> unit. ie, two trumpets each at the same db is not as loud as one trumpet
>> played more forcefully.
>
> Yeah, that is NOT likely. When considering 3 db, the increase in loudness
> is not a linear one. Each increase in db level is significantly louder
> than the previous step increase. Consider that 2 trumpets played at the
> same db could "sound" 3 times louder than 1 palyed at the same db.
log 2 = .3 (the definition of a decibel is the 10 x log of acoustical
energy, iirc).
The decibel is not "hard" physics, like energy, absolute temp, etc, but
rather a description of how we perceive acoustical energy.
And is only approximate at that, with freq, loudness itself, spatial
considerations, etc.
Play one trumpet at 60 db. Play second trumpet at 60 db. Play both
trumpets together, you "hear" 63 db.
The acoustical energy has indeed doubled, but not the perceived loudness.
Or so I lernt.
The point being, "loudness" is best achieved by modifying the original
source, not adding original sources. Which works to a shop's advantage, in
this case.
Not saying that a smaller compressor is necessarily quieter than a larger
compressor -- I have a Sam's Club 10 gal Alton (an unusual direct drive WITH
OIL!) that is so effingly loud, I use it as an alarm for low pressure!!!
The point was, that IF you have a quiet small compressor, you won't greatly
add to the noise factor by adding more quiet small compressors.
And, to the other points, indeed, you would not want them coming on all at
once, or even operating all at once (unless necessary), as that defeats the
purpose of staging. And yeah, circuitry is always an issue, which is why
God invented breaker panels.
And, not saying that the three operating together would be more efficient
than one big one -- just more efficient if the air load varies widely.
Note that there are probably a few ways to stage smaller compressors.
The obvious way is via pressure -- set each pressure switch successively
lower pressure, indicating demand.
Another way is to use timed relays to sense when one compressor has been
operating beyond a preset time, also indicating demand.
I'm a big fan of using volume to compensate for a small-ish compressor head.
Can really help if electricity is limited.
Also, a compressor that is a little too large for the electrical service can
be helped by changing pulley sizes, which if changed to reduce motor load
will also reduce cfm.
otoh, you could reverse this strategy to bump up cfm, if nec.
--
Mr. PV'd
Mae West (yer fav Congressman) to the Gangster (yer fav Lobbyist):
Hey, Big Boy, is that a wad (of cash) in yer pocket, or are you just
glad to see me??
>
>
>
>
"Michael A. Terrell" <[email protected]> wrote in message
news:[email protected]...
>
> "Proctologically Violated©®" wrote:
>>
>> log 2 = .3 (the definition of a decibel is the 10 x log of acoustical
>> energy, iirc).
>>
>> The decibel is not "hard" physics, like energy, absolute temp, etc, but
>> rather a description of how we perceive acoustical energy.
>> And is only approximate at that, with freq, loudness itself, spatial
>> considerations, etc.
>>
>> Play one trumpet at 60 db. Play second trumpet at 60 db. Play both
>> trumpets together, you "hear" 63 db.
>> The acoustical energy has indeed doubled, but not the perceived loudness.
>> Or so I lernt.
>
>
> Only if both are exactly in phase. Anything less, and the increase
> is under 3 dB. If they are exactly 180 degrees out of phase and at the
> same level, they cancel each other.
There ya go!
So just get two identical compressors, delay the start of the second one by
1/2 wavelength, and you will have zero db air!!
--
Mr. PV'd
Mae West (yer fav Congressman) to the Gangster (yer fav Lobbyist):
Hey, Big Boy, is that a wad (of cash) in yer pocket, or are you just
glad to see me??
>
>
> --
> http://improve-usenet.org/index.html
>
> aioe.org, Goggle Groups, and Web TV users must request to be white
> listed, or I will not see your messages.
>
> If you have broadband, your ISP may have a NNTP news server included in
> your account: http://www.usenettools.net/ISP.htm
>
>
> There are two kinds of people on this earth:
> The crazy, and the insane.
> The first sign of insanity is denying that you're crazy.
"jo4hn" <[email protected]> wrote in message
news:[email protected]...
> J. Clarke wrote:
>> Morris Dovey wrote:
>>> J. Clarke wrote:
>>>
>>>> Geez, how rich do you think that the people hanging out here _are_?
>>> I'm so poor my prop only has one blade...
>>
>> You've got a prop? Why in my day we had to flap our arms . . .
>>
> If God had meant men to fly, we would have been born with a propeller.
Well, he gave us assholes, so in principle, we could take off like rockets.
--
Mr. PV'd
Mae West (yer fav Congressman) to the Gangster (yer fav Lobbyist):
Hey, Big Boy, is that a wad (of cash) in yer pocket, or are you just
glad to see me??
On Dec 11, 9:42=A0pm, James Sweet <[email protected]> wrote:
> BobR wrote:
> > On Dec 10, 10:12 pm, Tony Hwang <[email protected]> wrote:
> >> DC wrote:
> >>> ..There are six things you need to know about compressors:
> >>> =A0The maximum PRESSURE that it develops, the rated VOLUME it
> >>> can deliver, the amount of compressed air it can STORE, how
> >>> LONG the motor can run (which is also known as "duty
> >>> cycle"), how much electrical POWER it's going to take to
> >>> run, and how much NOISE it's going to make....
> >>> Continued:http://atu.ca/AirCompressors
> >> Hi,
> >> Also whether compressor is lubricated or not.
> >> Never get non-lubricated one. I have a Campbell Hauser
> >> Extreme duty belt driven compressor which can be powered by either
> >> 120V or 208V. I am running it on 120V plugged into regular wall outlet
> >> in the garage. For what I do it is adequate. It can even blow sprinkle=
rs
> >> in the fall.
>
> > If you are talking about using the compressor only for power tools and
> > general use, I agree with the lubricated vs non-lubricated. =A0If you
> > plan to use that compressor for painting, I would recommend the non-
> > lubricated. =A0You don't want oil in the lines when painting.
>
> Good luck finding a single automotive paint shop, or pro business in
> general that gets by with an oil-less compressor. They're noisy, hot
> running things that burn out if you run them too hard. A good oil
> lubricated compressor exhausts a negligible amount of oil, and you need
> a really good filter and moisture separater in the line for painting anyw=
ay.- Hide quoted text -
>
> - Show quoted text -
Admittedly, my post does not dovetail with this thread since you're
talking electric motor driven compressors. However, I simply must
brag and chortle about my air cooled DIESEL milsurp air compressor.
Apparently it was designed to air up tires on jets. It's similar to
the "wheel barrow" compressors that carpenters use. It has a single
tank and a two stage compressor (175 psi!) compressor, belt driven by
a Yanmar 3 hp, fuel sipping, air cooled engine. It is well balanced
and light weight. It CHURNS out air. It starts from a battery or
with a rope. I swoon over its efficiency, reliability, and fuel
economy. In fact, I think I'll go give it a hug right now. Vernon
"Bob Haar" <[email protected]> wrote in message
news:C5695BE2.4398E4%[email protected]...
>
>> Don't let anyone fool you - it's not about horsepower and all that other
>> stuff people like to talk about. It's about SCFM - the ability of the
>> compressor to deliver air.
>
> You need to look at the SCFM rating at the pressure that your tools
> require.
SCFM = "Standard CFM". Standard pressure = 1 atmosphere, or free air.
"Ed Edelenbos" wrote:
> Chris (and Lew and Salty), thanks. I'm knee deep in trying to sort
> all of this compressor stuff out. I'm at the point where I can't
> see much of a use other than a brad/pin nailer and maybe an airbrush
> now and then.
Compressed air is like sex and money.
You never seem to have enough.
Lew
James Sweet wrote:
>
> Good luck finding a single automotive paint shop, or pro business in
> general that gets by with an oil-less compressor.
Some of the auto paint shops in my area have switched to turbines and
HVLP guns for use with water based finishes that get destroyed by the
smallest amount of oil.
"Lew Hodgett" <[email protected]> wrote in message
news:[email protected]...
> "Chris Friesen" wrote:
>
>> If I were ever to buy a stationary compressor, it would be one that you
>> wouldn't be able to run on a 120V circuit. A real 5HP one sounds about
>> right...30A at 240V.
>
> Make that a 5HP, cap start, cap run motor, driving a 2 stage compressor
> with an 80 gal vertical receiver and you will have gone about as far as
> you can go.
>
> BTW, you will need a 240V, 2P-40A CB to handle the inrush.
>
> Lew
This just makes me wonder what the application is. What sort of shop would
require a machine like that? I guess a production shop (or a shop where you
were doing auto mechanic work) would need a large compressor but I think
that would be overkill for most home woodworking workshops. What sort of
tools do any of you using compressors use?
Ed
"Chris Friesen" <[email protected]> wrote in message
news:[email protected]...
> Ed Edelenbos wrote:
>
>> This just makes me wonder what the application is. What sort of shop
>> would require a machine like that? I guess a production shop (or a shop
>> where you were doing auto mechanic work) would need a large compressor
>> but I think that would be overkill for most home woodworking workshops.
>> What sort of tools do any of you using compressors use?
>
> Currently I only have a little twin-tank one-lung luggable compressor. A
> bigger one would be useful primarily for spray guns and air tools (drills,
> sanders, etc.). The bigger ones are also generally quieter than the
> little ones.
>
> Also, most compressors aren't designed to run for more than 50% of the
> time. I was stapling down some sheathing with my little one and it was
> getting mighty warm.
>
> Chris
Chris (and Lew and Salty), thanks. I'm knee deep in trying to sort all of
this compressor stuff out. I'm at the point where I can't see much of a use
other than a brad/pin nailer and maybe an airbrush now and then.
Especially since I already have electric sanders and drills and dremels and
such out the wazoo. There are isolated instances where an impact wrench
would be a nice tool to have but not enough to justify the compressor it
would require. I have come to the conclusion that a cheap little compressor
isn't the most economical solution, though. The noise issue is one I've
been sort of pushing to the background. Hmmm.... more data.
Ed
<[email protected]> wrote in message
news:[email protected]...
***Snipped unreadable post***
>
> Much easier to do in Linux ,, than in WXP op systems
>
>
> [email protected] from Guadalajara MX ..
>
It may be easier to do in linux. Too bad it turns out unreadable text.
"Proctologically Violated©®" <[email protected]> wrote in message
news:[email protected]...
Snip
>>
>
> Not a bad article, if you don't mind the tone of the Very Authoritative
> Home-moaner.
>
> But as far as size goes, buying small-ish isn't necessarily a bad thing,
> as compressors are simply additive. Three small compressors should be
> exactly equivalent to one big one, with a few advantages:
>
> 1. You now have inherent staging, with all of its advantages: reduced
> electrical surge/"demand"; greater economy at low demand. Would proly
> need better pressure regulators in each unit, tho, as those in small units
> are usually not the best.
You really dont want all three coming on at the same time or running at the
same time either. A breaker could be blown very easily with 2 or more
running at the same time not to mention if 2 came on at the same time.
>
> 2. Likely quieter. Doubling the number of sources of the same noise only
> adds 3 db, vs. perhaps a much greater decibel increase of a larger unit.
> ie, two trumpets each at the same db is not as loud as one trumpet played
> more forcefully.
Yeah, that is NOT likely. When considering 3 db, the increase in loudness
is not a linear one. Each increase in db level is significantly louder than
the previous step increase. Consider that 2 trumpets played at the same db
could "sound" 3 times louder than 1 palyed at the same db.
On Sun, 14 Dec 2008 09:07:39 -0600, Leon wrote:
> Yeah, that is NOT likely. When considering 3 db, the increase in
> loudness is not a linear one. Each increase in db level is
> significantly louder than the previous step increase. Consider that 2
> trumpets played at the same db could "sound" 3 times louder than 1
> palyed at the same db.
What I was taught long ago (I have no cite as to its accuracy) is that
two instruments are 50% louder than one. Three are 67% louder than one
and so on. That no number of instruments ever gets you to twice as loud.
On 12/13/08 1:03 PMDec 13, "MikeWhy" <[email protected]> wrote:
> "Bob Haar" <[email protected]> wrote in message
> news:C5695BE2.4398E4%[email protected]...
>>
>>> Don't let anyone fool you - it's not about horsepower and all that other
>>> stuff people like to talk about. It's about SCFM - the ability of the
>>> compressor to deliver air.
>>
>> You need to look at the SCFM rating at the pressure that your tools
>> require.
>
> SCFM = "Standard CFM". Standard pressure = 1 atmosphere, or free air.
>
>
But you need to know how many SCFM at a particular delivery pressure. This
is often specified at 40 PSI or 90 PSI, for both tools and compressors. You
need to match the tool requirements.
On 2008-12-12, Steve Barker DLT <[email protected]> wrote:
> you can bet large (and small) body shops don't use oil-less compressors.
> The good old fashioned kind been working fine painting cars for a hundred
> years now.
I visited a large number of bankrupt industrial places. Not one had an
oil-less compressor.
There are good oil-less compressors out there, they are marketed to
dentists and are very expensive.
I sold one in 2004. It was 3 HP, dual headed.
http://yabe.algebra.com/~ichudov/misc/ebay/Airstar50Compressor/ebayhist.html
I bought it from the military, as "broken, uneconomical to repair,
condition H1" for $400. Turns out that what was broken was a tiny air
line going to pressure regulator. A minute with a knife fixed it. It
sold for $1,200.
i
On 2008-12-12, Bill Noble <[email protected]> wrote:
> With any decent compressor you don't need a filter to keep oil out of the
> air line, just a moisture trap. The only large capacity oil-less
> comperssors I am aware of are screw type. All of the industrial rated
> compressors that most of us can afford for a home shop use oil to lubricate
> the bearings, and they have a pressure system that has a small oil pump -
> good brands are ones like Quincy. Not good brands are the stuff sold at the
> big box stores.
I believe that screw compressors use even more oil than reciprocating,
and need a big filtering system. (usually. a good article about hem is
here:
http://en.wikipedia.org/wiki/Rotary_screw_compressor
i
James Sweet wrote:
>
> General rule for air compressors is buy the biggest one you can afford,
> because you always seem to need more air later than you thought. Mine is
> a "5HP" (yeah right) oiled reciprocating compressor which is just
> *barely* adequate to run my abrasive blasting cabinet. Had I know I'd
> get one of those, I'd have bought a larger compressor in the first
> place, though what I have is about as big as you can run from a 120V
> circuit.
If I were ever to buy a stationary compressor, it would be one that you
wouldn't be able to run on a 120V circuit. A real 5HP one sounds about
right...30A at 240V.
Chris
"Proctologically Violated©®" wrote:
>
> log 2 = .3 (the definition of a decibel is the 10 x log of acoustical
> energy, iirc).
>
> The decibel is not "hard" physics, like energy, absolute temp, etc, but
> rather a description of how we perceive acoustical energy.
> And is only approximate at that, with freq, loudness itself, spatial
> considerations, etc.
>
> Play one trumpet at 60 db. Play second trumpet at 60 db. Play both
> trumpets together, you "hear" 63 db.
> The acoustical energy has indeed doubled, but not the perceived loudness.
> Or so I lernt.
Only if both are exactly in phase. Anything less, and the increase
is under 3 dB. If they are exactly 180 degrees out of phase and at the
same level, they cancel each other.
--
http://improve-usenet.org/index.html
aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
[email protected] wrote:
>
> Air compressors have losses . V belts are a waste , not necessary .
>
> I just bought 6 HarborFright 40400 DIRECT drive ( 8 gallon tank)
> for
>
> $100 each .
>
>
Hi,
Which compressor would last longer? Belt driven or direct driven)lubed
or oil less)?
de VE6CGX
DC wrote:
> ..There are six things you need to know about compressors:
> The maximum PRESSURE that it develops, the rated VOLUME it
> can deliver, the amount of compressed air it can STORE, how
> LONG the motor can run (which is also known as "duty
> cycle"), how much electrical POWER it's going to take to
> run, and how much NOISE it's going to make....
>
> Continued: http://atu.ca/AirCompressors
>
Hi,
Also whether compressor is lubricated or not.
Never get non-lubricated one. I have a Campbell Hauser
Extreme duty belt driven compressor which can be powered by either
120V or 208V. I am running it on 120V plugged into regular wall outlet
in the garage. For what I do it is adequate. It can even blow sprinklers
in the fall.
Ed Edelenbos wrote:
> This just makes me wonder what the application is. What sort of shop would
> require a machine like that? I guess a production shop (or a shop where you
> were doing auto mechanic work) would need a large compressor but I think
> that would be overkill for most home woodworking workshops. What sort of
> tools do any of you using compressors use?
Currently I only have a little twin-tank one-lung luggable compressor.
A bigger one would be useful primarily for spray guns and air tools
(drills, sanders, etc.). The bigger ones are also generally quieter
than the little ones.
Also, most compressors aren't designed to run for more than 50% of the
time. I was stapling down some sheathing with my little one and it was
getting mighty warm.
Chris
Mike Marlow wrote:
> On Thu, 11 Dec 2008 22:10:59 -0800, Smitty Two cast forth these pearls of
> wisdom...:
>
>
>
>>>>If you are talking about using the compressor only for power tools and
>>>>general use, I agree with the lubricated vs non-lubricated. If you
>>>>plan to use that compressor for painting, I would recommend the non-
>>>>lubricated. You don't want oil in the lines when painting.
>>>
>>>Not true. A lubricated compressor is better for all wood shop uses than an
>>>oilless compressor. The oilless models are throw away, light duty, short
>>>lived compressors, and they make a ton of noise. Whether the compressor is
>>>lubricated with oil or not has no bearing on its use for painting. I think
>>>what you were thinking of was whether to use a line oiler. Certainly, if
>>>you're going to paint with that system, do not install a line oiler.
>>>Simply oil your tools through the chuck, as needed.
>>
>>Oh boy, here you go again, pushing my buttons. I've expounded at some
>>length about this in the past, but I'll be brief tonight. Cheap, shitty
>>compressors are oilless. However, that does not mean that all oilless
>>compressors are cheap and shitty. Mine is very, very good, and I sure as
>>hell don't want oil in my air most of the time. When I do, I can add it
>>myself. There's plenty of oil in your average oil-lubricated compressor
>>to destroy a paint job.
>
>
> Do you paint? I do. Never had an oil infiltration problem that was caused
> by the lubricant from my compressor. If you're encountering that, you've
> got compressor problems. For most people participating in threads like
> this, oilless translates directly to the cheap shitty stuff.
>
If you paint and don't want to have any problems, get a bottle of dry
Nitrogen and a good two stage regulator. NO oil No water that you can
blame as to your quality of the paint job. :)
John
On Fri, 12 Dec 2008 13:12:24 -0500, "Ed Edelenbos"
<[email protected]> wrote:
>
>
>"Lew Hodgett" <[email protected]> wrote in message
>news:[email protected]...
>> "Chris Friesen" wrote:
>>
>>> If I were ever to buy a stationary compressor, it would be one that you
>>> wouldn't be able to run on a 120V circuit. A real 5HP one sounds about
>>> right...30A at 240V.
>>
>> Make that a 5HP, cap start, cap run motor, driving a 2 stage compressor
>> with an 80 gal vertical receiver and you will have gone about as far as
>> you can go.
>>
>> BTW, you will need a 240V, 2P-40A CB to handle the inrush.
>>
>> Lew
>
>This just makes me wonder what the application is. What sort of shop would
>require a machine like that?
There might be a bit of a noise issue, too.
Step 1. Decide what you need.
Step 2. Multiply that by 1.5 - 2.0
Step 3. Shop for a high quality two stage, or a two piston oil crank
compressor if you only need a small one.
Step 4. Consider used, as you can sometimes get a killer deal on a big one.
Step 5. Install it right, electrically, piping, and air dryer.
Step 6. Enjoy and use, knowing you won't fry it, overwork it, or have it
fall short when you need it the most.
My observations from not following these steps.
Steve
On Dec 10, 9:09=A0pm, DC <[email protected]> wrote:
> ..There are six things you need to know about compressors:
> =A0The maximum PRESSURE that it develops, the rated VOLUME it
> can deliver, the amount of compressed air it can STORE, how
> LONG the motor can run (which is also known as "duty
> cycle"), how much electrical POWER it's going to take to
> run, and how much NOISE it's going to make....
>
> Continued:http://atu.ca/AirCompressors
All the advice in the article is good stuff. One critical point is
missing, however, The author should have added a section named
"Delivery". More power is wasted by undersized or over long hoses and
restrictive couplings than any other feature. The ubiquitous 1/4"
Milton M fittings almost everyone buys are serious offenders in that
respect. That is why so many shops for years kept buying air
compressors with higher and higher tank pressure ratings. The
currently popular 175 PSI rating is absurdly dangerous because design
parameters of most air tools are by regulation pegged at 90 PSI.
Milton some years ago introduced the "V" series plugs and couplers.
These have substantially higher flow rates than the "M" series which
98% of the lads reading this now have in their shop. The specs are
listed in the Milton catalog available (PDF) online. I converted my
shop some time ago when they were first introduced to improve my HVLP
paint systems. Couple this with a good quality 3/8" air hose (throw
out those wretched 1/4" hoses) and a modest 125 PSI compressor will
serve you very well for everything but removing earth mover wheels.
The laws of physics will work for you if you let them.
Joe
"Chris Friesen" wrote:
> If I were ever to buy a stationary compressor, it would be one that
> you wouldn't be able to run on a 120V circuit. A real 5HP one
> sounds about right...30A at 240V.
Make that a 5HP, cap start, cap run motor, driving a 2 stage
compressor with an 80 gal vertical receiver and you will have gone
about as far as you can go.
BTW, you will need a 240V, 2P-40A CB to handle the inrush.
Lew
Joe wrote:
> On Dec 10, 9:09 pm, DC <[email protected]> wrote:
>> ..There are six things you need to know about compressors:
>> The maximum PRESSURE that it develops, the rated VOLUME it
>> can deliver, the amount of compressed air it can STORE, how
>> LONG the motor can run (which is also known as "duty
>> cycle"), how much electrical POWER it's going to take to
>> run, and how much NOISE it's going to make....
>>
>> Continued:http://atu.ca/AirCompressors
>
> All the advice in the article is good stuff. One critical point is
> missing, however, The author should have added a section named
> "Delivery". More power is wasted by undersized or over long hoses and
> restrictive couplings than any other feature. The ubiquitous 1/4"
> Milton M fittings almost everyone buys are serious offenders in that
> respect. That is why so many shops for years kept buying air
> compressors with higher and higher tank pressure ratings. The
> currently popular 175 PSI rating is absurdly dangerous because design
> parameters of most air tools are by regulation pegged at 90 PSI.
> Milton some years ago introduced the "V" series plugs and couplers.
> These have substantially higher flow rates than the "M" series which
> 98% of the lads reading this now have in their shop. The specs are
> listed in the Milton catalog available (PDF) online. I converted my
> shop some time ago when they were first introduced to improve my HVLP
> paint systems. Couple this with a good quality 3/8" air hose (throw
> out those wretched 1/4" hoses) and a modest 125 PSI compressor will
> serve you very well for everything but removing earth mover wheels.
> The laws of physics will work for you if you let them.
>
> Joe
General rule for air compressors is buy the biggest one you can afford,
because you always seem to need more air later than you thought. Mine is
a "5HP" (yeah right) oiled reciprocating compressor which is just
*barely* adequate to run my abrasive blasting cabinet. Had I know I'd
get one of those, I'd have bought a larger compressor in the first
place, though what I have is about as big as you can run from a 120V
circuit.
BobR wrote:
> On Dec 10, 10:12 pm, Tony Hwang <[email protected]> wrote:
>> DC wrote:
>>> ..There are six things you need to know about compressors:
>>> The maximum PRESSURE that it develops, the rated VOLUME it
>>> can deliver, the amount of compressed air it can STORE, how
>>> LONG the motor can run (which is also known as "duty
>>> cycle"), how much electrical POWER it's going to take to
>>> run, and how much NOISE it's going to make....
>>> Continued:http://atu.ca/AirCompressors
>> Hi,
>> Also whether compressor is lubricated or not.
>> Never get non-lubricated one. I have a Campbell Hauser
>> Extreme duty belt driven compressor which can be powered by either
>> 120V or 208V. I am running it on 120V plugged into regular wall outlet
>> in the garage. For what I do it is adequate. It can even blow sprinklers
>> in the fall.
>
> If you are talking about using the compressor only for power tools and
> general use, I agree with the lubricated vs non-lubricated. If you
> plan to use that compressor for painting, I would recommend the non-
> lubricated. You don't want oil in the lines when painting.
Good luck finding a single automotive paint shop, or pro business in
general that gets by with an oil-less compressor. They're noisy, hot
running things that burn out if you run them too hard. A good oil
lubricated compressor exhausts a negligible amount of oil, and you need
a really good filter and moisture separater in the line for painting anyway.
Admittedly, my post does not dovetail with this thread since you're
talking electric motor driven compressors. However, I simply must
brag and chortle about my air cooled DIESEL milsurp air compressor.
Apparently it was designed to air up tires on jets. It's similar to
the "wheel barrow" compressors that carpenters use. It has a single
tank and a two stage compressor (175 psi!) compressor, belt driven by
a Yanmar 3 hp, fuel sipping, air cooled engine. It is well balanced
and light weight. It CHURNS out air. It starts from a battery or
with a rope. I swoon over its efficiency, reliability, and fuel
economy. In fact, I think I'll go give it a hug right now. Vernon
Now Vernon, you weren't over there squeezing her jugs now were you?
"Smitty Two" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>,
> "Steve Barker DLT" <[email protected]> wrote:
>
>> you can bet large (and small) body shops don't use oil-less compressors.
>> The good old fashioned kind been working fine painting cars for a hundred
>> years now.
>>
>
> You can bet anything you want. I rarely see a paint job that isn't
> orange-peeled, so my guess is that painters as a lot are as incompetent
> at their so-called profession as any other group. But I imagine that any
> decent paint shop would have some pretty good filters on the air, no
> matter how they compress it.
Orange peel has absolutely nothing to do with oil, it has to do with
viscosity and method of application.
Oil in the paint will cause fish eyes.
With any decent compressor you don't need a filter to keep oil out of the
air line, just a moisture trap. The only large capacity oil-less
comperssors I am aware of are screw type. All of the industrial rated
compressors that most of us can afford for a home shop use oil to lubricate
the bearings, and they have a pressure system that has a small oil pump -
good brands are ones like Quincy. Not good brands are the stuff sold at the
big box stores.
so, imagine away, but your inferences are incorrect.
>
>>
>> "Smitty Two" <[email protected]> wrote in message
>> news:[email protected]...
>>
>> >
>> > Oh boy, here you go again, pushing my buttons. I've expounded at some
>> > length about this in the past, but I'll be brief tonight. Cheap, shitty
>> > compressors are oilless. However, that does not mean that all oilless
>> > compressors are cheap and shitty. Mine is very, very good, and I sure
>> > as
>> > hell don't want oil in my air most of the time. When I do, I can add it
>> > myself. There's plenty of oil in your average oil-lubricated compressor
>> > to destroy a paint job.
above statement is just plain not true.
>Step 5. Install it right, electrically, piping, and air dryer.
And noise. Put it somewhere NOT where the people are. Use big
shock mounts and flexible lines to avoid coupling.
--
A host is a host from coast to [email protected]
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433
MikeWhy wrote:
> "Bob Haar" <[email protected]> wrote in message
> news:C5695BE2.4398E4%[email protected]...
>>
>>> Don't let anyone fool you - it's not about horsepower and all that
>>> other stuff people like to talk about. It's about SCFM - the
>>> ability of the compressor to deliver air.
>>
>> You need to look at the SCFM rating at the pressure that your tools
>> require.
>
> SCFM = "Standard CFM". Standard pressure = 1 atmosphere, or free
> air.
Pedantry is not pretty.
--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
john wrote:
>> Admittedly, my post does not dovetail with this thread since you're
>> talking electric motor driven compressors. However, I simply must
>> brag and chortle about my air cooled DIESEL milsurp air compressor.
>> Apparently it was designed to air up tires on jets. It's similar
>> to
>> the "wheel barrow" compressors that carpenters use. It has a
>> single
>> tank and a two stage compressor (175 psi!) compressor, belt driven
>> by
>> a Yanmar 3 hp, fuel sipping, air cooled engine. It is well
>> balanced
>> and light weight. It CHURNS out air. It starts from a battery or
>> with a rope. I swoon over its efficiency, reliability, and fuel
>> economy. In fact, I think I'll go give it a hug right now. Vernon
>
>
>
>
> 175 lb. is not enough pressure for many Jet aircraft tires, and most
> of the time dry nitrogen is used because of that fact. I remember a
> couple of jets taking 250 lb. in the mains. The Jetstar was one.
If I ever have a JetStar then I'll worry about getting a bigger
compressor.
Geez, how rich do you think that the people hanging out here _are_?
--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
Greg O wrote:
> "James Sweet" <[email protected]> wrote in message
> news:[email protected]...
>> >
>> General rule for air compressors is buy the biggest one you can
>> afford, because you always seem to need more air later than you
>> thought. Mine is a "5HP" (yeah right) oiled reciprocating compressor
>> which is just *barely* adequate to run my abrasive blasting cabinet.
>> Had I know I'd get one of those, I'd have bought a larger compressor
>> in the first place, though what I have is about as big as you can run
>> from a 120V circuit.
>
>
> 5HP on a 120 volt circuit? Somebody is pulling your leg, but looks like
> you realize it!
> I bought a Porter Cable 7HP, (sure you betcha), 60 gallon tank
> compressor a few years ago. Motor amps tell me that it is closer to 3
> HP. It does all I want it to do. I can run any air drill, DA sander I
> have, and it just about keeps up. And what I mean by that is for a home,
> weekend warrior shop it is just fine. I don't drill or sand continuously
> for hours on end. By the time the tank starts to run a bit low I am
> ready for a 30 second break, and the the compressor catches up again.
> Really I don't even notice any short comings. If you planed on running a
> sander continuously with no break at all it will not keep up.
> In my opinion, most any one man home shop can get along nicely with 10
> CFM at 90 PSI.
> Greg
They are very creative about horsepower ratings, same with shop vacs and
power ratings of cheap audio amplifiers. Ought to be illegal to fudge
them so severely but so far it isn't. There's the whole "peak HP" thing
they use, worthless number, but it sounds impressive.
"Mike Marlow" <[email protected]> wrote in message
news:[email protected]...
> On Thu, 11 Dec 2008 22:31:16 -0800, Smitty Two cast forth these pearls of
> wisdom...:
>
>> In article <[email protected]>,
>> "Steve Barker DLT" <[email protected]> wrote:
>>
>>> you can bet large (and small) body shops don't use oil-less compressors.
>>> The good old fashioned kind been working fine painting cars for a
>>> hundred
>>> years now.
>>>
>>
>> You can bet anything you want. I rarely see a paint job that isn't
>> orange-peeled, so my guess is that painters as a lot are as incompetent
>> at their so-called profession as any other group. But I imagine that any
>> decent paint shop would have some pretty good filters on the air, no
>> matter how they compress it.
>>
>
> Water traps mostly. The previous poster is correct though, with respect
> to
> the type of compressor you will find in body shops.
>
> --
>
> -Mike-
> [email protected]
Mike - quit wasting your time - this thread is cross posted to a bunch of
newsgroups and is going around in circles - there is some correct
information, much totally incorrect information (such as the orange peel
quote above) - just let this thing die
"Tony Hwang" <[email protected]> wrote in message
news:[email protected]...
> [email protected] wrote:
>>
>> Air compressors have losses . V belts are a waste , not necessary .
>>
>> I just bought 6 HarborFright 40400 DIRECT drive ( 8 gallon tank)
>> for
>>
>> $100 each .
>>
>>
>
> Hi,
> Which compressor would last longer? Belt driven or direct driven)lubed or
> oil less)?
> de VE6CGX
in general an industrial belt drive compressor will run 24X7 for years, I'd
expect an HF compressor in similar duty to be suffering in a month or less.
My quincy, bought used, is at least 35 years old.
Michael A. Terrell wrote:
> Ralph E Lindberg wrote:
>> In article <[email protected]>,
>> "Proctologically Violated©®" <[email protected]> wrote:
>>
>>> "Michael A. Terrell" <[email protected]> wrote in message
>>> news:[email protected]...
>>>> "Proctologically Violated©®" wrote:
>>>>> log 2 = .3 (the definition of a decibel is the 10 x log of acoustical
>>>>> energy, iirc).
>>>>>
>>>>> The decibel is not "hard" physics, like energy, absolute temp, etc, but
>>>>> rather a description of how we perceive acoustical energy.
>>>>> And is only approximate at that, with freq, loudness itself, spatial
>>>>> considerations, etc.
>>>>>
>>>>> Play one trumpet at 60 db. Play second trumpet at 60 db. Play both
>>>>> trumpets together, you "hear" 63 db.
>>>>> The acoustical energy has indeed doubled, but not the perceived loudness.
>>>>> Or so I lernt.
>>>>
>>>> Only if both are exactly in phase. Anything less, and the increase
>>>> is under 3 dB. If they are exactly 180 degrees out of phase and at the
>>>> same level, they cancel each other.
>>> There ya go!
>>> So just get two identical compressors, delay the start of the second one by
>>> 1/2 wavelength, and you will have zero db air!!
>>> --
>> What that is how noise canceling head-phones work, it's not how two
>> noise sources work. But the above is very much spot on (yes I actually
>> make my living dealing with sound and noise, in the water but it still
>> works the same)
>
>
> I made mine with RF. Everything from microwave receivers that
> recovered data from the noise floor, to 5 MW EIRP UHF transmitters. At
> one time I owned a commercial sound business. My record was clear audio
> five miles away from some pole mounted music grade horns, driven with a
> 65 watt amplifier. It was at a high school football stadium, with open
> bleachers. The custom speaker mounts were made of heavy aluminum 'U"
> channel. 8" wide, 18 inches long, and three inches deep. The thinnest
> part was 5/8"
>
When I was a kid, I found a screw in driver for a
stadium horn. I taped it to a washing machine rotor
which was horn shaped and made a pretty good loud
speaker. I then took a carbon microphone from an
old telephone, put in series with some D cells and
the home made speaker and that sucker was loud. The
feedback from dropping the microphone into the horn
was horrid and being a kid, I just had to use it to
chase the dogs all over the farm. Ah, the life of a
young mad scientist.
TDD
Ralph E Lindberg wrote:
>
> In article <[email protected]>,
> "Proctologically Violated©®" <[email protected]> wrote:
>
> > "Michael A. Terrell" <[email protected]> wrote in message
> > news:[email protected]...
> > >
> > > "Proctologically Violated©®" wrote:
> > >>
> > >> log 2 = .3 (the definition of a decibel is the 10 x log of acoustical
> > >> energy, iirc).
> > >>
> > >> The decibel is not "hard" physics, like energy, absolute temp, etc, but
> > >> rather a description of how we perceive acoustical energy.
> > >> And is only approximate at that, with freq, loudness itself, spatial
> > >> considerations, etc.
> > >>
> > >> Play one trumpet at 60 db. Play second trumpet at 60 db. Play both
> > >> trumpets together, you "hear" 63 db.
> > >> The acoustical energy has indeed doubled, but not the perceived loudness.
> > >> Or so I lernt.
> > >
> > >
> > > Only if both are exactly in phase. Anything less, and the increase
> > > is under 3 dB. If they are exactly 180 degrees out of phase and at the
> > > same level, they cancel each other.
> >
> > There ya go!
> > So just get two identical compressors, delay the start of the second one by
> > 1/2 wavelength, and you will have zero db air!!
> > --
> What that is how noise canceling head-phones work, it's not how two
> noise sources work. But the above is very much spot on (yes I actually
> make my living dealing with sound and noise, in the water but it still
> works the same)
I made mine with RF. Everything from microwave receivers that
recovered data from the noise floor, to 5 MW EIRP UHF transmitters. At
one time I owned a commercial sound business. My record was clear audio
five miles away from some pole mounted music grade horns, driven with a
65 watt amplifier. It was at a high school football stadium, with open
bleachers. The custom speaker mounts were made of heavy aluminum 'U"
channel. 8" wide, 18 inches long, and three inches deep. The thinnest
part was 5/8"
--
http://improve-usenet.org/index.html
aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.
On Mon, 15 Dec 2008 06:46:02 -0800, Smitty Two cast forth these pearls of
wisdom...:
> In article <[email protected]>,
> Ignoramus23050 <[email protected]> wrote:
>
>
>>
>> You could have bought a real compressor for this kind of money.
>
> Wouldn't work. We have fake air here.
While I may not like your choice of compressors, I really like your sense
of humor...
--
-Mike-
[email protected]
J. Clarke wrote:
> Morris Dovey wrote:
>> J. Clarke wrote:
>>
>>> Geez, how rich do you think that the people hanging out here _are_?
>> I'm so poor my prop only has one blade...
>
> You've got a prop? Why in my day we had to flap our arms . . .
>
If God had meant men to fly, we would have been born with a propeller.
On Sat, 13 Dec 2008 12:59:52 -0500, "Proctologically Violated©®"
<[email protected]> wrote:
>
>"DC" <[email protected]> wrote in message
>news:[email protected]...
>> ..There are six things you need to know about compressors:
>> The maximum PRESSURE that it develops, the rated VOLUME it
>> can deliver, the amount of compressed air it can STORE, how
>> LONG the motor can run (which is also known as "duty
>> cycle"), how much electrical POWER it's going to take to
>> run, and how much NOISE it's going to make....
>>
>> Continued: http://atu.ca/AirCompressors
>>
>
>Not a bad article, if you don't mind the tone of the Very Authoritative
>Home-moaner.
>
>But as far as size goes, buying small-ish isn't necessarily a bad thing, as
>compressors are simply additive. Three small compressors should be exactly
>equivalent to one big one, with a few advantages:
>
>1. You now have inherent staging, with all of its advantages: reduced
>electrical surge/"demand"; greater economy at low demand. Would proly need
>better pressure regulators in each unit, tho, as those in small units are
>usually not the best.
>
>2. Likely quieter. Doubling the number of sources of the same noise only
>adds 3 db, vs. perhaps a much greater decibel increase of a larger unit.
>ie, two trumpets each at the same db is not as loud as one trumpet played
>more forcefully.
>
>3. Smaller = portable, if nec.
>4. May be easier to fit numerous smaller compressors in nooks and crannies.
>
>5. Repair is easier, due to redundancy -- you won't be totally out of air.
>And Quincy's are nice, but I could proly buy a whole new small HD/c.h. for
>the price of one Q repair.
>
>6. One can be set up for special apps, like painting, etc.
>
>Proly some other advantages, as well.
>
>HD/campbell hausefeld has a very nice upright 30 gal compressor, dual
>voltage motor, belt driven cast iron compressor w/oil, sight glass, wheels,
>VERY quiet. I would buy multiples of these in a minute.
>
>Also, in many cases, larger resevoir volume is all that is needed, not a
>bigger compressor. I have numerous small makeup tanks for about 70 gals,
>works great with one small compressor.
>Would work even for air tools, depending on how much you use them vs. your
>total gallons.
My compressor is an extreme duty Campbell Hausfeld, 30 gallon tank on
wheels. I don't use it often, does a great job, but wow, the noise. I
don't have a sprayer...yet.
In article <[email protected]>,
"Proctologically Violated©®" <[email protected]> wrote:
> "Michael A. Terrell" <[email protected]> wrote in message
> news:[email protected]...
> >
> > "Proctologically Violated©®" wrote:
> >>
> >> log 2 = .3 (the definition of a decibel is the 10 x log of acoustical
> >> energy, iirc).
> >>
> >> The decibel is not "hard" physics, like energy, absolute temp, etc, but
> >> rather a description of how we perceive acoustical energy.
> >> And is only approximate at that, with freq, loudness itself, spatial
> >> considerations, etc.
> >>
> >> Play one trumpet at 60 db. Play second trumpet at 60 db. Play both
> >> trumpets together, you "hear" 63 db.
> >> The acoustical energy has indeed doubled, but not the perceived loudness.
> >> Or so I lernt.
> >
> >
> > Only if both are exactly in phase. Anything less, and the increase
> > is under 3 dB. If they are exactly 180 degrees out of phase and at the
> > same level, they cancel each other.
>
> There ya go!
> So just get two identical compressors, delay the start of the second one by
> 1/2 wavelength, and you will have zero db air!!
> --
What that is how noise canceling head-phones work, it's not how two
noise sources work. But the above is very much spot on (yws I actually
make my living dealing with sound and noise, in the water but it still
works the same)
--
--------------------------------------------------------
Personal e-mail is the n7bsn but at amsat.org
This posting address is a spam-trap and seldom read
RV and Camping FAQ can be found at
http://www.ralphandellen.us/rv
> Admittedly, my post does not dovetail with this thread since you're
> talking electric motor driven compressors. However, I simply must
> brag and chortle about my air cooled DIESEL milsurp air compressor.
> Apparently it was designed to air up tires on jets. It's similar to
> the "wheel barrow" compressors that carpenters use. It has a single
> tank and a two stage compressor (175 psi!) compressor, belt driven by
> a Yanmar 3 hp, fuel sipping, air cooled engine. It is well balanced
> and light weight. It CHURNS out air. It starts from a battery or
> with a rope. I swoon over its efficiency, reliability, and fuel
> economy. In fact, I think I'll go give it a hug right now. Vernon
175 lb. is not enough pressure for many Jet aircraft tires, and most of
the time dry nitrogen is used because of that fact. I remember a couple
of jets taking 250 lb. in the mains. The Jetstar was one.
John
In article <[email protected]>,
Mike Marlow <[email protected]> wrote:
> For most people participating in threads like
> this, oilless translates directly to the cheap shitty stuff.
Yep. That's why every time someoone brings it up, I respond. My
compressor is oilless. It was not cheap, it is not shitty, and it is
about as quiet as a compressor can be.
My argument isn't so much about compressors as with the
correlation/causation confusion that most people are too stupid to
understand even if you 'splain it to 'em with a sledge hammer.
So instead of saying, "whatever you do, don't buy an oilless," I'd be
happier if people would say "whatever you do, don't buy a cheap, shitty
compressor."
In article <[email protected]>,
"Steve Barker DLT" <[email protected]> wrote:
> you can bet large (and small) body shops don't use oil-less compressors.
> The good old fashioned kind been working fine painting cars for a hundred
> years now.
>
You can bet anything you want. I rarely see a paint job that isn't
orange-peeled, so my guess is that painters as a lot are as incompetent
at their so-called profession as any other group. But I imagine that any
decent paint shop would have some pretty good filters on the air, no
matter how they compress it.
>
> "Smitty Two" <[email protected]> wrote in message
> news:[email protected]...
>
> >
> > Oh boy, here you go again, pushing my buttons. I've expounded at some
> > length about this in the past, but I'll be brief tonight. Cheap, shitty
> > compressors are oilless. However, that does not mean that all oilless
> > compressors are cheap and shitty. Mine is very, very good, and I sure as
> > hell don't want oil in my air most of the time. When I do, I can add it
> > myself. There's plenty of oil in your average oil-lubricated compressor
> > to destroy a paint job.
In article <[email protected]>,
Mike Marlow <[email protected]> wrote:
> On Thu, 11 Dec 2008 18:21:06 -0800 (PST), BobR cast forth these pearls of
> wisdom...:
>
> > On Dec 10, 10:12 pm, Tony Hwang <[email protected]> wrote:
> >> DC wrote:
> >>> ..There are six things you need to know about compressors:
> >>> The maximum PRESSURE that it develops, the rated VOLUME it
> >>> can deliver, the amount of compressed air it can STORE, how
> >>> LONG the motor can run (which is also known as "duty
> >>> cycle"), how much electrical POWER it's going to take to
> >>> run, and how much NOISE it's going to make....
> >>
> >>> Continued:http://atu.ca/AirCompressors
> >>
> >> Hi,
> >> Also whether compressor is lubricated or not.
> >> Never get non-lubricated one. I have a Campbell Hauser
> >> Extreme duty belt driven compressor which can be powered by either
> >> 120V or 208V. I am running it on 120V plugged into regular wall outlet
> >> in the garage. For what I do it is adequate. It can even blow sprinklers
> >> in the fall.
> >
> > If you are talking about using the compressor only for power tools and
> > general use, I agree with the lubricated vs non-lubricated. If you
> > plan to use that compressor for painting, I would recommend the non-
> > lubricated. You don't want oil in the lines when painting.
>
> Not true. A lubricated compressor is better for all wood shop uses than an
> oilless compressor. The oilless models are throw away, light duty, short
> lived compressors, and they make a ton of noise. Whether the compressor is
> lubricated with oil or not has no bearing on its use for painting. I think
> what you were thinking of was whether to use a line oiler. Certainly, if
> you're going to paint with that system, do not install a line oiler.
> Simply oil your tools through the chuck, as needed.
Oh boy, here you go again, pushing my buttons. I've expounded at some
length about this in the past, but I'll be brief tonight. Cheap, shitty
compressors are oilless. However, that does not mean that all oilless
compressors are cheap and shitty. Mine is very, very good, and I sure as
hell don't want oil in my air most of the time. When I do, I can add it
myself. There's plenty of oil in your average oil-lubricated compressor
to destroy a paint job.
In article <[email protected]>,
Mike Marlow <[email protected]> wrote:
> On Mon, 15 Dec 2008 06:46:02 -0800, Smitty Two cast forth these pearls of
> wisdom...:
>
> > In article <[email protected]>,
> > Ignoramus23050 <[email protected]> wrote:
> >
> >
> >>
> >> You could have bought a real compressor for this kind of money.
> >
> > Wouldn't work. We have fake air here.
>
> While I may not like your choice of compressors, I really like your sense
> of humor...
Thanks for having the courage to admit that, Mike!
In article <[email protected]>,
Ignoramus23050 <[email protected]> wrote:
>
> You could have bought a real compressor for this kind of money.
Wouldn't work. We have fake air here.
In article <[email protected]>,
"Proctologically Violated©®" <[email protected]> wrote:
> "Smitty Two" <[email protected]> wrote in message
> news:[email protected]...
> > In article <[email protected]>,
> > Mike Marlow <[email protected]> wrote:
> >
> >> For most people participating in threads like
> >> this, oilless translates directly to the cheap shitty stuff.
> >
> > Yep. That's why every time someoone brings it up, I respond. My
> > compressor is oilless. It was not cheap, it is not shitty, and it is
> > about as quiet as a compressor can be.
>
> What brand/model compressor is this? Price?
http://www.sears.com/shc/s/p_10153_12605_00916778000P
"Proctologically Violated©®" <[email protected]> wrote in message
news:[email protected]...
>
>
> 2. Likely quieter. Doubling the number of sources of the same noise only
> adds 3 db, vs. perhaps a much greater decibel increase of a larger unit.
> ie, two trumpets each at the same db is not as loud as one trumpet played
> more forcefully.
>
>
I will argue that point!
Seems to me that the larger HP cast iron pump compressors are very quiet,
certainly when compared to a 1HP oil less unit. My cheapy 7HP, (really about
3HP) Porter Cable is quieter than the 1-1/2 Craftsman it replaced. Much
quieter than the oil less models we have at my job. Some of the 5HP cast
iron compressors are strangely quiet. Low RPM pump and motor reduce noise a
bunch, but at a premium price.
Greg
On Fri, 12 Dec 2008 06:39:36 -0800, Smitty Two cast forth these pearls of
wisdom...:
> In article <[email protected]>,
> Mike Marlow <[email protected]> wrote:
>
>> For most people participating in threads like
>> this, oilless translates directly to the cheap shitty stuff.
>
> Yep. That's why every time someoone brings it up, I respond. My
> compressor is oilless. It was not cheap, it is not shitty, and it is
> about as quiet as a compressor can be.
>
> My argument isn't so much about compressors as with the
> correlation/causation confusion that most people are too stupid to
> understand even if you 'splain it to 'em with a sledge hammer.
>
> So instead of saying, "whatever you do, don't buy an oilless," I'd be
> happier if people would say "whatever you do, don't buy a cheap, shitty
> compressor."
As is true of most everything. We do however tend to fall back to the
rule, rather than the exception, since for 99% of the folks, the exception
is either out of their reach, or in some other way, not really applicable.
That makes the rule (for all intents and purposes) seem more absolute.
I do agree that in the greater sense of understanding something, the
exception should be noted.
--
-Mike-
[email protected]
On Fri, 12 Dec 2008 14:16:54 -0500, "Ed Edelenbos"
<[email protected]> wrote:
>
>
>"Chris Friesen" <[email protected]> wrote in message
>news:[email protected]...
>> Ed Edelenbos wrote:
>>
>>> This just makes me wonder what the application is. What sort of shop
>>> would require a machine like that? I guess a production shop (or a shop
>>> where you were doing auto mechanic work) would need a large compressor
>>> but I think that would be overkill for most home woodworking workshops.
>>> What sort of tools do any of you using compressors use?
>>
>> Currently I only have a little twin-tank one-lung luggable compressor. A
>> bigger one would be useful primarily for spray guns and air tools (drills,
>> sanders, etc.). The bigger ones are also generally quieter than the
>> little ones.
>>
>> Also, most compressors aren't designed to run for more than 50% of the
>> time. I was stapling down some sheathing with my little one and it was
>> getting mighty warm.
>>
>> Chris
>
>Chris (and Lew and Salty), thanks. I'm knee deep in trying to sort all of
>this compressor stuff out. I'm at the point where I can't see much of a use
>other than a brad/pin nailer and maybe an airbrush now and then.
>Especially since I already have electric sanders and drills and dremels and
>such out the wazoo. There are isolated instances where an impact wrench
>would be a nice tool to have but not enough to justify the compressor it
>would require. I have come to the conclusion that a cheap little compressor
>isn't the most economical solution, though. The noise issue is one I've
>been sort of pushing to the background. Hmmm.... more data.
>
>Ed
You can buy a cheap little oiled air compressor with a 10 gallon tank
for about $99-$200 that will be adequate for pretty much anything you
will be doing around the house, including running framing and roofing
nailers, paint sprayers, and other "normal" stuff. You may have to
pause occasionally while nailing to let the compressor catch up with
you, but it's not really an issue.
Here's a typical example:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90234
I've seen this compressor on sale for $100 with a rebate.
Lots of places carry something comparable.
Greg O wrote:
> "James Sweet" <[email protected]> wrote in message
> news:[email protected]...
>> >
>> General rule for air compressors is buy the biggest one you can
>> afford, because you always seem to need more air later than you
>> thought. Mine is a "5HP" (yeah right) oiled reciprocating compressor
>> which is just *barely* adequate to run my abrasive blasting cabinet.
>> Had I know I'd get one of those, I'd have bought a larger compressor
>> in the first place, though what I have is about as big as you can run
>> from a 120V circuit.
>
>
> 5HP on a 120 volt circuit? Somebody is pulling your leg, but looks like
> you realize it!
> I bought a Porter Cable 7HP, (sure you betcha), 60 gallon tank
> compressor a few years ago. Motor amps tell me that it is closer to 3
> HP. It does all I want it to do. I can run any air drill, DA sander I
> have, and it just about keeps up. And what I mean by that is for a home,
> weekend warrior shop it is just fine. I don't drill or sand continuously
> for hours on end. By the time the tank starts to run a bit low I am
> ready for a 30 second break, and the the compressor catches up again.
> Really I don't even notice any short comings. If you planed on running a
> sander continuously with no break at all it will not keep up.
> In my opinion, most any one man home shop can get along nicely with 10
> CFM at 90 PSI.
> Greg
Hi,
My main goal was to use it to blow sprinkler system in the fall.
What I got does it OK but very slowly. Wish I had a bigger one.
Then I hve to run 208 circuit for it. As a compromise I am happy ith
what I have. That Hp rating is bogus. They don't tell trun Hp, they
invented a term peak Hp to fool general consumers. They do the same with
stereo system. When they brag about 200W output power it is barely 50W rms.
you can bet large (and small) body shops don't use oil-less compressors.
The good old fashioned kind been working fine painting cars for a hundred
years now.
s
"Smitty Two" <[email protected]> wrote in message
news:[email protected]...
>
> Oh boy, here you go again, pushing my buttons. I've expounded at some
> length about this in the past, but I'll be brief tonight. Cheap, shitty
> compressors are oilless. However, that does not mean that all oilless
> compressors are cheap and shitty. Mine is very, very good, and I sure as
> hell don't want oil in my air most of the time. When I do, I can add it
> myself. There's plenty of oil in your average oil-lubricated compressor
> to destroy a paint job.
On 2008-12-15, Smitty Two <[email protected]> wrote:
> In article <[email protected]>,
> "Proctologically Violated??" <[email protected]> wrote:
>
>> "Smitty Two" <[email protected]> wrote in message
>> news:[email protected]...
>> > In article <[email protected]>,
>> > Mike Marlow <[email protected]> wrote:
>> >
>> >> For most people participating in threads like
>> >> this, oilless translates directly to the cheap shitty stuff.
>> >
>> > Yep. That's why every time someoone brings it up, I respond. My
>> > compressor is oilless. It was not cheap, it is not shitty, and it is
>> > about as quiet as a compressor can be.
>>
>> What brand/model compressor is this? Price?
>
> http://www.sears.com/shc/s/p_10153_12605_00916778000P
You could have bought a real compressor for this kind of money.
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On Mon, 15 Dec 2008 05:52:22 -0800, Smitty Two cast forth these pearls of
wisdom...:
> In article <[email protected]>,
> "Proctologically Violated©®" <[email protected]> wrote:
>
>> "Smitty Two" <[email protected]> wrote in message
>> news:[email protected]...
>>> In article <[email protected]>,
>>> Mike Marlow <[email protected]> wrote:
>>>
>>>> For most people participating in threads like
>>>> this, oilless translates directly to the cheap shitty stuff.
>>>
>>> Yep. That's why every time someoone brings it up, I respond. My
>>> compressor is oilless. It was not cheap, it is not shitty, and it is
>>> about as quiet as a compressor can be.
>>
>> What brand/model compressor is this? Price?
>
> http://www.sears.com/shc/s/p_10153_12605_00916778000P
That is a very low delivery compressor. It is only suited for short useage
tools or pumping up tires. At 5.1SCFM, it will not support orbital
sanders, or other higher volume air tools. Nor will it support an HVLP
spray gun. If what you're planning to use it with is nail guns and the
likes, then it should work fine, but a lesser compressor (less cost as
well) would do that same job.
--
-Mike-
[email protected]