Air Brushing – Air Brush

Question:

What they should have told you is the recommended rpm of the pump. Too manufacturer’s provide a minimum rpm for the specific purpose of providing splash oiling. These two specs tyically run in the neighborhood of 800-1200 rpm and half that respectively. Of course this depends on the size and type of the pump.  Sounds to me like you might have a mid-size (as far as home compressors go) single stage pump. Speedaire uses lower HP motors on their setups and provide higher cfm ratings (as a comparision).  I always wondered about this as well as the advertised HP ratings of some of these compressors.  (How can a 6 HP motor only draw 22 amps??? – the math just ain’t right!) Anywho…motors are easy to come by. Someone suggested Northern – which has several good choices. I don’t know first hand about Harbor Freight’s motors, but they too have several economical options. Mark from Pasadena, MD – Hide quoted text — Show quoted text – Well, I know now that I cannot currently run my 240VAC compressor on 120VAC current (until both phases of 120VAC in the building are connected). Until that time comes (maybe weeks, months, years, decades?)…I can not run the compressor. So either I get another compressor, get a different motor to use in the interim, or move to another location. I spoke with Ingersoll-Rand and they suggested using nothing smaller than a 3HP 115VAC motor. They said 3HP is the smallest they would safely recommend because the compressor pump has splash lubrication and a smaller HP motor might not turn the pump sufficiently fast to provide adequate lubrication. Now, I’m not that hip to motor specs and sources (talk of the devil, I did purchase a book a week ago dealing with electric motors/power transmission) so I’m curious if anyone knows of a source of cheap used, surplus,or rebuilt/rewound motors? Also, another newsgroup that deals specifically with electric motors? Specs: Usage: Air Compressor -1 phase -115VAC -3HP -Hz 60 -3450 RPM (or within 5%) -continuous duty -SF: 1.15 -Ball Bearing -thermal protection: manual reset -size/frame: XR56Y  (or close match) I’ll need a 7/8" keyed shaft for the pulley I anyone has one to sell or knows of a good, inexpensive source, lay ‘er on me. Thanks. Cheers, -Neal

Response:

It uses 26 amps. Thats 3.5 more than the stock motor. A #10 guage wire (possibly #8) should handle it, no? Would a 3HP motor be able to talk to the pump?

Good luck at getting 26A out of a standard 15A apartment wall plug. Fitch

Response:

bin there done that Hi Neal I had a similar problem in that I need to convert my portable scuba compressor to electric but make it plug compatible with marine power. I found a 3hp 115v motor for $150 from a compressor company (air power 800-334-4509). 3hp is the limit on 115volt. some thing s you need to know is that some 115v motor are not reversible so you may need to now the direction of rotation before you order.   I installed this on a 20 amp breaker with 10 gauge wire all by itself. in theory it calls for a 30 amp at startup but runs around  15amps. So far it has not tripped or blown the breaker. I even think it might be able to run on a 15 amp circuit as long as I start the compressor with the valves in the open position so there is no additional load placed on the startup phase (yet to try it). hope this helps AndyM

– Hide quoted text — Show quoted text – Well, I know now that I cannot currently run my 240VAC compressor on 120VAC current (until both phases of 120VAC in the building are connected). Until that time comes (maybe weeks, months, years, decades?)…I can not run the compressor. So either I get another compressor, get a different motor to use in the interim, or move to another location. I spoke with Ingersoll-Rand and they suggested using nothing smaller than a 3HP 115VAC motor. They said 3HP is the smallest they would safely recommend because the compressor pump has splash lubrication and a smaller HP motor might not turn the pump sufficiently fast to provide adequate lubrication. Now, I’m not that hip to motor specs and sources (talk of the devil, I did purchase a book a week ago dealing with electric motors/power transmission) so I’m curious if anyone knows of a source of cheap used, surplus,or rebuilt/rewound motors? Also, another newsgroup that deals specifically with electric motors? Specs: Usage: Air Compressor -1 phase -115VAC -3HP -Hz 60 -3450 RPM (or within 5%) -continuous duty -SF: 1.15 -Ball Bearing -thermal protection: manual reset -size/frame: XR56Y  (or close match) I’ll need a 7/8" keyed shaft for the pulley I anyone has one to sell or knows of a good, inexpensive source, lay ‘er on me. Thanks. Cheers, -Neal

Response:

There are lots of guys on these NG’s that can tell you anything about electric motors.

Don’t doubt it. Waiting for them to put in their appearance. Btw, got a recommendation on fertile motor newsgroup? If you need to replace an existing 220V motor with one that will run on 110V, then try to get one with the same frame. Read the nameplate on the motor carefully. You will likely find a frame number like 56C or something. Those frame numbers are not specific to motor manufacturers, they comply with NEMA spec.

Yes. It’s a "XR56Y". From what I can gather, the suffix "Y" designates non-standard mounting. I’m still a baby when it comes to motors. Waiting for that used text book to arrive. My memory’s just been jogged!!!! An electronics/electrical internet mentor in Canada who had been helping me design a microprocessor circuit once mentioned an esoteric classic benchmark book on motor winding/rewinding. Advised me to read the book and to seek some work rewinding motors to learn more about them (time wasn’t right, I was more DC now I’m moving into AC). Before I hooked up with him, I was cluelessly considering making my own solenoids (big beefy muthas)…I was just learning about them and couldn’t find massive ones like I wanted…called a motor rewind shop in NJ and talked windings and solenoids. The guy invited me to come on over and use as much copper as I needed to make some solenoids. Never took him up on it (used OTS stuff)…but…might be a great resource for a used or custom wound motor. Hey, maybe I can burn another week month?)of my life…winding motors! Yippeee! God good, it does kill the cat. Are you absolutely positively certain that your motor cannot be rewired to run at 115V?

No. I know there are 220V-only motors, but in my whole life I’ve never seen one. Usually you can take off the cover to the motor’s connection box, and there is a printed diagram glued to the inside which will show how to reconnect for different voltage. The nameplate will give a clue as well.

The nameplate only lists 230V. I’ll maybe poke inside tomorrow. Curious what it looks like in there anyway Be aware that your new motor will draw twice the current that your old one did (power = volts * amps, and you cut the volts by 2 and keep the power output the same only by doubling the amps).

I was considering a 3HP for the new 115VAC motor. Mine is 5HP, 230VAC. You will need a special circuit wired for this motor. NO WAY it will run on a normal household 15A or 20A circuit. A good rule of thumb is that the largest 115V motor you can run on a 15A circuit is 1.5hp which means you will need a 30A circuit.

My service has #8 wire feeds to the apartment breaker panel. I could run a #8 wire circuit for the motor alone, with a big breaker. Your current compressor may have a magnetic switch on it. If so, it will also need to be upgraded, and this will cost almost as much as the motor, sadly.

No magnetic switch. If it doesn’t have a mag switch then it is depending directly on the pressure switch (that’s the little box on the pipe coming right off the main air tank, with wires going towards the electric motor) to switch the motor current, and you will then have to look at the pressure switch to make sure it is rated to switch 30 amps.

Yes, that’s the setup. Correct, inside the switch enclosure it has a label: 1 Phase Ratings: Volts   FLA   LRA 120     34    144 240     26    130 On 145 PSI Off 175 PSI (what does LRA refer to?) Usually, they aren’t, which is why they use mag switches. Fortunately, those pressure switches are cheap (they sell them at Home Depot) and you may be able to buy one rated to switch 30A. When it comes time to buy a motor, the very best way is to buy used.

I was thinking the same thing. Been scouring ebay. Failing that, you can go cheap (buy a Marathon power tool motor from Harbor Freight) or you can go quality (call your local Leeson distributor and whine until they give you 55% discount off of list, but Leeson are top quality US motors.)

Can you give me some examples of your whining technique? I’m willing and eager to learn if it can effectively lower motor prices. What a great skill! All this is a little like closing the barn door after the horse has left – the time to figure all these costs was when you were contemplating installing this air compressor in the first place.

Well, I was informed by the contractor that I had 240VAC service…the asbestos (if you’ve followed the entire sordid and probably boring saga) is a hush-hush type thing that threw a wrenchin the works. Shit happens. Still, sometimes you get a compressor when you get it. It can cost an awful lot of money to rework the electrics on a machine, though.

Don’t worry: this compressor will have it’s day of glory. Thanks a bunch Grant. Cheers, Neal

Response:

I can comiserate, I have the same compressor.

How do you like it? I listened to it when I picked it up and it didn’t sound nearly as loud as I was expecting it to be. I use a 2P-40 and #8AWG wire to service it.

What’s the 2P refer to? That’s the problem, you will probably pop the breakers before the motor ever gets started. An inrush current of 10-12 times the FLA shown on the namplate are not uncommom. IOW, an inrush of 300 Amps is not out of the question. It might only last for 0.10 seconds, but that probably will exceed the magnetic capacity of a typical residential thermal-magnetic bkr found in your panel.

Lew, this is still something I’ve yet to understand. 300 amps is alot: wouldn’t that overpower most modest shops’ service, let alone residential? Spare me the aggrivation. Spend the $400-$500 and get the JGA with a 2 qt pressure pot and do it right the first time.

It’s a small $400 touch up gun: gravity fed and rotatable side mounted cup. Iwata’s newest incarnation of the 100 series, LHP-100-LVG Fine art painting mostly w/thinner mediums are what I’ll be using it for. I’ll be indulging in Iwata’s airbrushes as well. There is another way. Go get one of these little tank mounted units on wheels powered by a 1 HP electric motor. Pipe it so the 80 gal tank is basically a receiver.

What additional modifications does this entail for the pumping compessor and for the receiving compressor? Hardware? It will take a long time to pump up the system, but it will also last a long time before the motor comes back on. When you move to the new loft, sell the little unit.

I’ve considered this as well, but the noise factor is an issue…this is an apartment building and the lil’ cheap one’s are generally prohibitively loud. Tommorow, a friend (and perhaps me if I have the time) will visit an elderly retired machinist. He mentioned he has a 60 gallon compressor or some such thing that runs on 115VAC. Maybe he’ll let me borrow the motor (or have another laying around), the entire pump/motor system, or the whole damn thing. His entire friggin’ basement is a mausoleum of tools covering every conceivable surface, labyrinthian passages, mazes, cubby holes, floor to ceiling and back….all chock full of machinist tools. He spends his days stripping copper wire with his teeth (well…OK, not his teeth), sometimes with cubscouts, which he then recycles. Built some bad as machinery in his day. Slowly the ends will come together… Life is short, build machinery. Thanks a bunch. Cheers, -Neal

Response:

"N." writes: Hi ya Lew, Is your admonition directed against my generic interest in a 115VAC compressor replacement motor as a solution, or directed SPECIFICALLY against the motor sold by  Nothern Tools that Jerry referenced?

The motor itself. The design basically sucks. It’s at the outer limits of single phase design. Weight is not an issue: I have a tank (literally) of a compressor with an 80 gallon verticle tank. If only you could have seen us transport and move the thing. Pure folly.

I can comiserate, I have the same compressor. I use a 2P-40 and #8AWG wire to service it. The motor by comparison is like an ant crawling over a sycamore tree.

Or a mosquito trying to rape an elephant, AKA: The height of conceit. Inefficiency also isn’t an issue monetarily (unless it causes functional problems in the electric service itself).

That’s the problem, you will probably pop the breakers before the motor ever gets started. (the latter from ebay or surplus).

A real one is dirt cheap. Trust me. Futhermore, my future plans involve moving my work (tools an’ all) into an art studio proper & preferably with attendant 3 Phase service (I’ve suffered from bogus electricity for the past 16 years and enough is enough)

Best idea you’ve had yet. Expense? It’s dirt cheap: only $90.  Harbor Frieght looks to have the same motor for the same price, with free shipping to boot.

Maybe. It uses 26 amps. Thats 3.5 more than the stock motor. A #10 guage wire (possibly #8) should handle it, no? Would a 3HP motor be able to talk to the pump?

An inrush current of 10-12 times the FLA shown on the namplate are not uncommom. IOW, an inrush of 300 Amps is not out of the question. It might only last for 0.10 seconds, but that probably will exceed the magnetic capacity of a typical residential thermal-magnetic bkr found in your panel. LVLP (low volume,low pressure) spraygun

Spare me the aggrivation. Spend the $400-$500 and get the JGA with a 2 qt pressure pot and do it right the first time. Do you think it could work??

As I’ve tried to say earlier, Very Iffy. There is another way. Go get one of these little tank mounted units on wheels powered by a 1 HP electric motor. Pipe it so the 80 gal tank is basically a receiver. It will take a long time to pump up the system, but it will also last a long time before the motor comes back on. When you move to the new loft, sell the little unit. HTH — Lew S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland) Visit: <http://home.earthlink.net/~lewhodgett for Pictures Btw, here’s the pesky compressor:

http://cgi.ebay.com/ebaymotors/aw-cgi/eBayISAPI.dll?ViewItem&item=600… r=0&t=0&showTutorial=0&ed=1011815124&indexURL=0&rd=1 – Hide quoted text — Show quoted text – Thanks. Cheers, Neal

Response:

There are lots of guys on these NG’s that can tell you anything about electric motors. If you need to replace an existing 220V motor with one that will run on 110V, then try to get one with the same frame. Read the nameplate on the motor carefully. You will likely find a frame number like 56C or something. Those frame numbers are not specific to motor manufacturers, they comply with NEMA spec. Then you will know what you need – a 3hp 115VAC motor with the same frame number. Are you absolutely positively certain that your motor cannot be rewired to run at 115V? I know there are 220V-only motors, but in my whole life I’ve never seen one. Usually you can take off the cover to the motor’s connection box, and there is a printed diagram glued to the inside which will show how to reconnect for different voltage. The nameplate will give a clue as well. Be aware that your new motor will draw twice the current that your old one did (power = volts * amps, and you cut the volts by 2 and keep the power output the same only by doubling the amps). You will need a special circuit wired for this motor. NO WAY it will run on a normal household 15A or 20A circuit. A good rule of thumb is that the largest 115V motor you can run on a 15A circuit is 1.5hp which means you will need a 30A circuit. Your current compressor may have a magnetic switch on it. If so, it will also need to be upgraded, and this will cost almost as much as the motor, sadly. If it doesn’t have a mag switch then it is depending directly on the pressure switch (that’s the little box on the pipe coming right off the main air tank, with wires going towards the electric motor) to switch the motor current, and you will then have to look at the pressure switch to make sure it is rated to switch 30 amps. Usually, they aren’t, which is why they use mag switches. Fortunately, those pressure switches are cheap (they sell them at Home Depot) and you may be able to buy one rated to switch 30A. When it comes time to buy a motor, the very best way is to buy used. Failing that, you can go cheap (buy a Marathon power tool motor from Harbor Freight) or you can go quality (call your local Leeson distributor and whine until they give you 55% discount off of list, but Leeson are top quality US motors.) All this is a little like closing the barn door after the horse has left – the time to figure all these costs was when you were contemplating installing this air compressor in the first place. Still, sometimes you get a compressor when you get it. It can cost an awful lot of money to rework the electrics on a machine, though. Grant Erwin Kirkland, Washington – Hide quoted text — Show quoted text – Well, I know now that I cannot currently run my 240VAC compressor on 120VAC current (until both phases of 120VAC in the building are connected). Until that time comes (maybe weeks, months, years, decades?)…I can not run the compressor. So either I get another compressor, get a different motor to use in the interim, or move to another location. I spoke with Ingersoll-Rand and they suggested using nothing smaller than a 3HP 115VAC motor. They said 3HP is the smallest they would safely recommend because the compressor pump has splash lubrication and a smaller HP motor might not turn the pump sufficiently fast to provide adequate lubrication. Now, I’m not that hip to motor specs and sources (talk of the devil, I did purchase a book a week ago dealing with electric motors/power transmission) so I’m curious if anyone knows of a source of cheap used, surplus,or rebuilt/rewound motors? Also, another newsgroup that deals specifically with electric motors? Specs: Usage: Air Compressor -1 phase -115VAC -3HP -Hz 60 -3450 RPM (or within 5%) -continuous duty -SF: 1.15 -Ball Bearing -thermal protection: manual reset -size/frame: XR56Y  (or close match) I’ll need a 7/8" keyed shaft for the pulley I anyone has one to sell or knows of a good, inexpensive source, lay ‘er on me. Thanks. Cheers, -Neal

Response:

Don’t go there. Many years ago, had a customer who bought almost this exact motor from me in lots of 500 at a time.

Hi ya Lew, Is your admonition directed against my generic interest in a 115VAC compressor replacement motor as a solution, or directed SPECIFICALLY against the motor sold by  Nothern Tools that Jerry referenced? The motor was heavy, inefficient, and most of all, EXPENSIVE.

Here’s my stand on these issues: Weight is not an issue: I have a tank (literally) of a compressor with an 80 gallon verticle tank. If only you could have seen us transport and move the thing. Pure folly. The motor by comparison is like an ant crawling over a sycamore tree. Inefficiency also isn’t an issue monetarily (unless it causes functional problems in the electric service itself). My electric meter isn’t hooked up so the Electric Utility Co. has been charging me a fixed rate for the last 6 months and it is very acceptable. If they replace the meter it will be because of the abatement of the aesbestos issue in the basement…and as soon as the electric utility goes in to do the work, then the contractor will go in simutaneously and add the other AC phase to give me 208VAC (…assuming of course the landlord has paid him the money he owes him . Then…I can remove the El-Cheapo temporary 115VAC motor, sell it (or trundle it down a cliff), and replace my original 230VAC motor with a Buck Booster (the latter from ebay or surplus). Furthermore, my future plans involve moving my work (tools an’ all) into an art studio proper & preferably with attendant 3 Phase service (I’ve suffered from bogus electricity for the past 16 years and enough is enough)…hopefully the move accomplished by sometime in 2002-2003 (and if not…I’ll end up going mad anyway–so none of this will really matter). Expense? It’s dirt cheap: only $90.  Harbor Frieght looks to have the same motor for the same price, with free shipping to boot. Doubt you could get the motor up to speed with out blowing your service off the wall.

It uses 26 amps. Thats 3.5 more than the stock motor. A #10 guage wire (possibly #8) should handle it, no? Would a 3HP motor be able to talk to the pump? Thing is, I can get by for several months if need be with reduced performance from the compressor. I bought a burly unit because of all the advice I had read suggesting getting more air than one needs because you’ll really dig it and more likely than not, become a full fledged air user eventually maturing into an air afficionado, advancing well beyond the horizens of your immediate needs and stated intentions. If the motor doesn’t deprive the pump of lubrication or burn the building down, it could forseeably serve my immediate  needs: staplers, airbrush, chinzy air hammer, and perhaps pneumatic process experiementation (air cylinders, actuators). It wont be run continuously or everyday, just occasionally (so I say now). Ever hear the expression, "You can’t get there from here"? In a nutshell, that’s your problem.

Lew, I like fine tools and quality equipment (that’s why I bought an IR rather than a cheaper junker) but this is a quick fix strategy, and only that. Putting aside the negative associations you’ve have with this product in the past, do you think it could work as a stop-gap measure, and nothng more? Do you think it could work?? Btw, here’s the pesky compressor: http://cgi.ebay.com/ebaymotors/aw-cgi/eBayISAPI.dll?ViewItem&item=600… Thanks. Cheers, Neal

Response:

  Northern Tool, phone 1-800-556-7885, sells very inexpensive motors. They advertize a 115vac single phase 3 HPmotor for only $90.00.

– Hide quoted text — Show quoted text – Well, I know now that I cannot currently run my 240VAC compressor on 120VAC current (until both phases of 120VAC in the building are connected). Until that time comes (maybe weeks, months, years, decades?)…I can not run the compressor. So either I get another compressor, get a different motor to use in the interim, or move to another location. I spoke with Ingersoll-Rand and they suggested using nothing smaller than a 3HP 115VAC motor. They said 3HP is the smallest they would safely recommend because the compressor pump has splash lubrication and a smaller HP motor might not turn the pump sufficiently fast to provide adequate lubrication. Now, I’m not that hip to motor specs and sources (talk of the devil, I did purchase a book a week ago dealing with electric motors/power transmission) so I’m curious if anyone knows of a source of cheap used, surplus,or rebuilt/rewound motors? Also, another newsgroup that deals specifically with electric motors? Specs: Usage: Air Compressor -1 phase -115VAC -3HP -Hz 60 -3450 RPM (or within 5%) -continuous duty -SF: 1.15 -Ball Bearing -thermal protection: manual reset -size/frame: XR56Y  (or close match) I’ll need a 7/8" keyed shaft for the pulley I anyone has one to sell or knows of a good, inexpensive source, lay ‘er on me. Thanks. Cheers, -Neal

Response:

Well, I know now that I cannot currently run my 240VAC compressor on 120VAC current (until both phases of 120VAC in the building are connected). Until that time comes (maybe weeks, months, years, decades?)…I can not run the compressor. So either I get another compressor, get a different motor to use in the interim, or move to another location. I spoke with Ingersoll-Rand and they suggested using nothing smaller than a 3HP 115VAC motor. They said 3HP is the smallest they would safely recommend because the compressor pump has splash lubrication and a smaller HP motor might not turn the pump sufficiently fast to provide adequate lubrication. Now, I’m not that hip to motor specs and sources (talk of the devil, I did purchase a book a week ago dealing with electric motors/power transmission) so I’m curious if anyone knows of a source of cheap used, surplus,or rebuilt/rewound motors? Also, another newsgroup that deals specifically with electric motors? Specs: Usage: Air Compressor -1 phase -115VAC -3HP -Hz 60 -3450 RPM (or within 5%) -continuous duty -SF: 1.15 -Ball Bearing -thermal protection: manual reset -size/frame: XR56Y  (or close match) I’ll need a 7/8" keyed shaft for the pulley I anyone has one to sell or knows of a good, inexpensive source, lay ‘er on me. Thanks. Cheers, -Neal

Response:

"N." writes: Well, I know now that I cannot currently run my 240VAC compressor on 120VAC current (until both phases of 120VAC in the building are connected). Until that time comes (maybe weeks, months, years, decades?)…I can not run the compressor.

<snip a sad tale of woe about 115 VAC motors Don’t go there. Many years ago, had a customer who bought almost this exact motor from me in lots of 500 at a time. The motor was heavy, inefficient, and most of all, EXPENSIVE. Doubt you could get the motor up to speed with out blowing your service off the wall. Ever hear the expression, "You can’t get there from here"? In a nutshell, that’s your problem. — Lew S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland) Visit: <http://home.earthlink.net/~lewhodgett for Pictures

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