Can a 110 volt compressor run a 3/4" impact?

[reader2580]

I have never seen a torque multiplier before. Learning new stuff here.

If I spent that many hours on the side of ANY road, I think I would break loose and lube every lug nut every time before my rig left the driveway. After that roadside adventure, with my bunch, all my trips would be solo. I could sell big guy and get a Prius.

I must have lived a charmed life.

The 18 hour adventure was a failed tag axle wheel bearing. A mobile mechanic had to drive over three hours to get to us. This is the first tire problem on the road.

Some friends of mine have been stuck in Reno for a week with a motor home that needs new front spindles. They had the wheel bearings replaced two weeks ago, but they were not replaced properly and locked up. They should be leaving today.

 

[reader2580]

The problem with roadside assistance programs is they don't pay squat so nobody is bending over backwards to help their customers.

The couple times I have needed help was in remote areas outside of normal business hours. Nobody wants to head out late at night and drive 50 miles for the little they get paid. In the 18 hour case they claimed nobody was available. They told me a specific tow company was leaving at 6 am. I called the company at 7 am and they had never agreed to do the job. I finally heard from a tow company at 8 am and they could send a mechanic to fix it. They never mentioned the mechanic was at another location three hours away.

 

[BukitCase]

Be VERY careful with LUBRICATION of any kind - I can tell you from first-hand experience that LUBE on a fastener combined with torque intended for DRY fastener, tends to result in SNAPPED bolts - and this is with BRAND NEW GRADE 8 bolts... Steve

http://www.fandisc.com/disc-springs-suggested-tightening-torque-values.html

 

[DerekV]

The absolute most you can get out of a 110V outlet @ 15 amps is about 2.5hp: 160V (RMS) * 15A = 2400W = 3.2hp, and 20% loss gives you ~2.5hp.

1 hp can move 15.59cfm @ 14.7psi, and the relationship is pretty linear, so you get ~2.5cfm @ 90psi.

2.5cfm/hp * 2.5hp = 5.25cfm.

Huh??

120 is the RMS voltage out of a standard wall outlet. That is the figure you want to use for the calculation since it's the effective voltage. The peak voltage in the sine wave is ~170v, but that's for a split second (aka not the effective voltage).

1.5hp is really the most you can get out of a 15amp outlet 120v outlet, and 2hp for a 20amp 120v outlet.

 

[Loscaldazar]

A 110V compressor will run a 3/4 drive impact. For a short period of time. You'll have to take frequent breaks to get a wheel off. You may not even be able to run it at a high enough PSI long enough to actually break a lug loose. But the impact can run at full power for a brief time period (dependent on max PSI, air tank reserve, and Motor CFM).

Despite what almost everyone here says, CFM does not determine power. PSI determines powers. CFM determines if a compressor can sustain a high enough PSI to let you continue on full power (or if you have to take breaks to let the compressor recharge). Furthermore, the CFM rating of compressors is the rate at which the air compressor is putting air into the tank, not the rate at which your tool is getting air. If motor CFM truly mattered for tool performance, your tool would not work when the motor is not running (as the CFM is effectively zero for the motor).

It may seem like an arbitrary distinction, but it becomes very important for most air tools that aren't as large as a 3/4" drive impact.

The CFM out of an air tank is usually 30-100 CFM depending on your set up (or higher!), so rarely is the actual amount of air you can flow a problem. Instead it is how pressurized (PSI) it is at your tool.

You could get a few bursts out of a 110V compressor, and have to wait for it to recharge in between lugs.

I'd go the route of a torque multiplier. More expensive (than a used 110V compressor), but will ultimately be faster.

 

[Olafur]

Anything rolling down the road on 11R24 tires that requires 4xx lb/ft of torque on the lugs -at least over here- has engine driven air compressor with 100% duty cycle putting out 8-10bars of air.

In all likelihood it also has big enough air tank(s) to supply 3/4" or even 1" drive wrench to remove single lug at a time. Possibly more. Rev the engine a bit and it will load up the tanks in a min, or two.

I run 1/2 drive impact wrench from the onboard air system in my 4x4 off road rig. It has engine driven York compressor and 3 gal air tank. I bet the OP's bus has bigger compressor and much larger air tanks than that.

I would explore this and hook up 1/2" air line to the existing tank, or possibly add extra air tank for this purpose if needed. Simple and fun project.

 

[bsaint]

Huh??

120 is the RMS voltage out of a standard wall outlet. That is the figure you want to use for the calculation since it's the effective voltage. The peak voltage in the sine wave is ~170v, but that's for a split second (aka not the effective voltage).

1.5hp is really the most you can get out of a 15amp outlet 120v outlet, and 2hp for a 20amp 120v outlet.

Not only this but his math was wrong too. 5.25 cfm out of a 2.5hp compressor is terrible.

 

[reader2580]

Anything rolling down the road on 11R24 tires that requires 4xx lb/ft of torque on the lugs -at least over here- has engine driven air compressor with 100% duty cycle putting out 8-10bars of air.

In all likelihood it also has big enough air tank(s) to supply 3/4" or even 1" drive wrench to remove single lug at a time. Possibly more. Rev the engine a bit and it will load up the tanks in a min, or two.

Yes, the vehicle has an air system. A number of years ago I had planned to tap one of the air tanks, but the unused ports are only 1/8" or 1/4" NPT. Not big enough to supply a 3/4" or 1" impact wrench.

The ideal place to tap into the system would be right after the air dryer, but the tanks all have check valves that would limit the volume of air if I connected there. I need to be sure that anything I do won't cause issues with the air braking system. (I have schematics for the air system.)

 

[Loscaldazar]

Yes, the vehicle has an air system. A number of years ago I had planned to tap one of the air tanks, but the unused ports are only 1/8" or 1/4" NPT. Not big enough to supply a 3/4" or 1" impact wrench.

The ideal place to tap into the system would be right after the air dryer, but the tanks all have check valves that would limit the volume of air if I connected there. I need to be sure that anything I do won't cause issues with the air braking system. (I have schematics for the air system.)

1/4 NPT will work just fine for a 3/4 impact, provided you do not have every fitting being 1/4."

Even the most basic 1/4" NPT air tool fitting will flow 32 CFM (and the best flow around 70 CFM). Getting an adapter from 1/4 to 1/2 and 1/2 to 3/4 will flow even better than that air tool fitting (as they should be wide open all the way through).

A 3/4 drive impact only uses 24-35 CFM under load (not talking average CFM here, which is a useless measurement IMHO).

Again, people worry too much about CFM, while not understanding what it truly is. I know a couple of members get irritated every time I post about why CFM isn't everything in the air tool world, but this is why I talk about it. People generally have a poor understanding of CFM and how it affects air tool performance, as well as what changing fittings actually does to an air system. Generally, looking at CFM usually allows you to make a good predication on whether an air tool will work with a given air supply system, but it is far from everything and only part of the bigger picture.

Ultimately, you need to get the air to your tool at a high enough PSI to run it. CFM influences that, but most people reference motor CFM when talking about motor CFM, which is very wrong when talking about getting power out of an air system.

Now I did say a 1/4 fitting will work provided every fitting is not 1/4. If 1/4 has a high enough CFM rating, why is this?

PSI.

Too many 1/4 fitting will result in too high of a PSI drop, meaning you will get no power out of your impact wrench.

 

[Codejack]

Huh??

120 is the RMS voltage out of a standard wall outlet. That is the figure you want to use for the calculation since it's the effective voltage. The peak voltage in the sine wave is ~170v, but that's for a split second (aka not the effective voltage).

1.5hp is really the most you can get out of a 15amp outlet 120v outlet, and 2hp for a 20amp 120v outlet.

Well, then, where are all these 120V 2.5hp compressors coming from?

 

[DerekV]

Well, then, where are all these 120V 2.5hp compressors coming from?

Two words = marketing ****.

 

[Jp267]

IMO most of these new cheaper compressors are way under powered. I saw a 60 gallon. Can't remember brand, that couldn't produce over 9.0 CFM@90. That seems ridiculous to me. Yes it did 150psi so good. Way underpowered motor if you ask me.

Sent from my XT1635-02 using Tapatalk

 

[WittHay]

Use Baldor motors quite often, 1 hp starts easy. 1 1/2 hp breakers start to trip.

Never had much luck trying to take wheels of semis, using the truck air system. Sort of like taking off car wheels with a 3/8 impact you can get most of the lugs off but there might be one stubborn one.

A 3/4" drive impact is not a 1" impact plus the pressure cuts out at 120 on older trucks. Its slow because you have 20 nuts to take off to do a inside dual and there is always some nuts that are tighter than the rest. I am talking about wheels that haven't been off in a while

 

[CGT80]

1/4 NPT will work just fine for a 3/4 impact, provided you do not have every fitting being 1/4."

Even the most basic 1/4" NPT air tool fitting will flow 32 CFM (and the best flow around 70 CFM). Getting an adapter from 1/4 to 1/2 and 1/2 to 3/4 will flow even better than that air tool fitting (as they should be wide open all the way through).

A 3/4 drive impact only uses 24-35 CFM under load (not talking average CFM here, which is a useless measurement IMHO).

Again, people worry too much about CFM, while not understanding what it truly is. I know a couple of members get irritated every time I post about why CFM isn't everything in the air tool world, but this is why I talk about it. People generally have a poor understanding of CFM and how it affects air tool performance, as well as what changing fittings actually does to an air system. Generally, looking at CFM usually allows you to make a good predication on whether an air tool will work with a given air supply system, but it is far from everything and only part of the bigger picture.

Ultimately, you need to get the air to your tool at a high enough PSI to run it. CFM influences that, but most people reference motor CFM when talking about motor CFM, which is very wrong when talking about getting power out of an air system.

Now I did say a 1/4 fitting will work provided every fitting is not 1/4. If 1/4 has a high enough CFM rating, why is this?

PSI.

Too many 1/4 fitting will result in too high of a PSI drop, meaning you will get no power out of your impact wrench.

I agree that pressure is as important as cfm.

Many people recommend 1/2" hose for a 100-150 foot run. It is probably more than a 150' run of 1/4" hose to my plasma table (requires 7cfm at 75-85 psi) and 1/4" is no problem. But, it is fed directly from an 80 gallon tank and the compressor is set to come on at 140 psi and shut off at 170 psi. A regulator is set at 125 psi right before the filters by the plasma. After a 5 micron filter and a 0.01 micron filter, the pressure never drops below 110psi right before the plasma, while running. The compressor in the same building as the plasma table, with no more than 50' of hose wasn't cutting it. It is single stage and the pressure could drop to 105 psi at the compressor before it would turn on. The pressure made all the difference in the world.

On that truck/bus maybe one or two of those 1/4" ports could feed an auxiliary tank with larger hose connected to it. Of course it would depend on the pressure of the on board air. You could even put in ball valves leading to the aux tank, so it would effectively not exist while driving, if there is a chance it could effect the brakes.

The cordless impacts look quite impressive and would be great to go along with the torque tool and a breaker bar. I used a similar too for the gland nut on my air cooled vw engine. They are torqued to 300+ foot pounds, IIRC.

 

[Olafur]

Never had much luck trying to take wheels of semis, using the truck air system. Sort of like taking off car wheels with a 3/8 impact you can get most of the lugs off but there might be one stubborn one.

A 3/4" drive impact is not a 1" impact plus the pressure cuts out at 120 on older trucks. Its slow because you have 20 nuts to take off to do a inside dual and there is always some nuts that are tighter than the rest. I am talking about wheels that haven't been off in a while

Here we have a guy with actual experience, good post. Needless to say if the OP wants to avoid future problems with his lugs on the side of the road he should also take your earlier advice to heart.

Maybe get a mobile truck tire guy with a 1" impact to take them off. Then buy all new outer and inner nuts, put some anti seize on them and torque them right.

Anyway, since we don't know the capabilities or tank size the OP is using it's difficult to give specific advice. One idea would be simply to try one of the unused 1/4" ports on his existing air tanks, hook up the 3/4" gun and see what happens. Not to difficult to do.

Usually these systems load up the tanks in series and one (or more) tanks only get air after the others have loaded up to a certain pressure. I would try to tap into the primary system.

There is also the option to tap into a bigger line from one of the tanks using T if you know what you are doing. And like I have mentioned before, adding extra tank for this purpose with 1/2" outlet is something that would certainly work to drive 1" drive gun. However it would take time to remove 20 nuts with it. In emergency, extra half an hour waiting for the air system to load up the tank between lugs - doesn't matter if you are certain to get the job done. Better than bet on something that might work or not.

That said, if the OP is in decent health the simplest solution is strong enough breaker bar or ratchet and extension (cheater pipe). Keep it simple - is always good plan for emergencies.

 

[reader2580]

A 3/4" drive impact is not a 1" impact plus the pressure cuts out at 120 on older trucks. Its slow because you have 20 nuts to take off to do a inside dual and there is always some nuts that are tighter than the rest. I am talking about wheels that haven't been off in a while

It sounds like it might be a lost cause to use my built-in air source as it doesn't go above 120 PSI although it is rated at 16.5 CFM.

I don't want to spend $400 or more on parts, a 1" impact wrench, and sockets to find out it won't remove the lug nuts.

 

[Olafur]

It sounds like it might be a lost cause to use my built-in air source as it doesn't go above 120 PSI although it is rated at 16.5 CFM.

I don't want to spend $400 or more on parts, a 1" impact wrench, and sockets to find out it won't remove the lug nuts.

Until you post details about your ride it's impossible to tell. Very strange method from someone seeking help to spoon-feed information. We still don’t know anything about your bus.

 

[Lelandwelds]

Despite what almost everyone here says, CFM does not determine power. PSI determines powers.

I think your comments nailed it so much I went and searched some of your other posts. I do think it is a bit more accurate to say you need so much cfm @ so and so pressure for best tool performance. You need both.

It's a little funny because I keep hearing different versions of the same argument: cfm vs psi, hp vs torque, amps vs volts, velocity vs. Energy

 

[WittHay]

Until you post details about your ride it's impossible to tell. Very strange method from someone seeking help to spoon-feed information. We still don’t know anything about your bus.

I assume the OP has a Greyhound type bus converted to a motorhome. Picture of buses showing the driver and tag axle. The trailers are the type of stuff I work on

The question is if you are out in the middle of nowhere, what can you use to change a tire on a Greyhound bus.

The op said that his Makita 3/4 cordless that puts out 780 ft.lbs working torque would not take them off. Would a new IR 3/4 air impact be better?

What I use is Chicago 797-6 1" impact that puts out 900 ft.lbs. working torque but requires 150 to 175 psi and weighs close to 30 lbs.

 

[cherrybomb]

As a trucker,I've been in your shoes.Your misfortune has maybe taught others on this site some lessions.When your having trouble,help doesn't always work in a hurry or respond quickly.The traveling games rules always change.I would think Pre-Trip,check and go over scenarios in your drive way.Torque multpliers,breaker bars,jacks,blocks of wood,lights,the correct socket and extension.All valuable pieces of a puzzle,forget one thing and whats your time and safety worth along the road?If you've had a shop change a tire,sometimes his tooling puts more torque on than what you can get off.A little never seize ,helps the future disassembly. Break downs are never pretty,but are part of the game.Your focus is safety and minimizing the problem.Pre planning and good equipment is my recommendation.Good luck on your travels.

 

[reader2580]

Until you post details about your ride it's impossible to tell. Very strange method from someone seeking help to spoon-feed information. We still don’t know anything about your bus.

The vehicle is a Dina Viaggio 1000 coach bus. It uses 11R24.5 tires with the lug nuts torqued to 475 ft lbs. The wheels are stud pilot. The steer tires are BF Goodrich ST230 and the drive and tag tires are Roadmaster RM185. The engine air compressor is a Bendix Truflo 750 that puts out 16.5 CFM @ 120 PSI.

I don't see how any of this is relevant to my original question of if a 110 volt compressor will supply enough air for a 3/4" impact wrench. I currently own two 3/4" pneumatic impacts and would be willing to buy a 1" impact wrench if necessary.

I have a Makita XWT07Z LXT cordless 3/4" impact with 1,250 ft lb nut busting torque that will not budge any of the lug nuts.

 

[Olafur]

The on board air system in this thing has no problems running 1" impact wrench. And you seem to have plenty of space to add extra 20 gal air tank for this purpose. Air impacts are usually rated 90 psi at the handle. 120 Psi @ the tank + 1/2" hose and you are all set.

I would charge the extra tank from one of the existing tanks via ball valve. There is also the possibility to tap into more tanks, ball valve on each of them. By doing this you are benefiting from their volume as well. Preferably the ball valves should be right at the existing tanks. But I guess accessing them there could be difficult. Next best thing would be to mount the extra tank in accessible place and have the ball valves there. When the valves are OFF there is no change to the brake system, and no extra delay to charge up the extra tank every time you use the bus. I would probably use 10-12mm nylon lines between the tanks depending on how long the lines have to be. Needless to say this installation should be done with care, because you don't want to loose air via leaking line on the turnpike.

When you are using your impact the parking (emergency) brake is ON and it is spring loaded so any disruption to the air brake system doesn't matter.

 

[Olafur]

I assume the OP has a Greyhound type bus converted to a motorhome. Picture of buses showing the driver and tag axle. The trailers are the type of stuff I work on

The question is if you are out in the middle of nowhere, what can you use to change a tire on a Greyhound bus.

The op said that his Makita 3/4 cordless that puts out 780 ft.lbs working torque would not take them off. Would a new IR 3/4 air impact be better?

What I use is Chicago 797-6 1" impact that puts out 900 ft.lbs. working torque but requires 150 to 175 psi and weighs close to 30 lbs.

If everything is optimal a good 3/4" air gun will remove the lugs (even quite easily) , but usually this isn't the case and therefore we don't bother with them. 1" drive all the way.

I really can't comment on 3/4" cordless impacts, my limited experience with them hasn't been promising at all.

 

[dnschmidt]

Bcradio has this one nailed. If you can't move it with 1400 foot pounds your damn lug nuts are too tight. These tools remove Honda crank bolts like they're nothing so I'm pretty sure they should kill lug nuts. Drive your bus over to a Milwaukee dealer and tell him that you want to try out in his parking lot the second generation FUEL High Torque Impact. Tell him if it can remove the lug nuts from your bus that you'll buy it. That should be incentive enough to get his interest.

 

[reader2580]

I wouldn't doubt that some or all of the lug nuts are too tight. Some tire shops are good at using torque wrenches, but not all of them. I saw one shop use an impact to put the lugs on and then use a torque wrench after that. A torque wrench doesn't do much good if the nut is already too tight.

I don't have a way to get the lug nuts loose right now, but it would be a lengthy project to loosen and re-torque 80 lug nuts.

 

[WittHay]

The newer hub mounted style is about 7/8" thread size and just normal thread. So any powerful 1/2 impact should be able to take them off.

The trouble with Budd outer nuts is the thread size, it is 1 1/8-16 and they are left hand thread on the driver side. Cordless impacts i believe are more powerful in the loosening mode than the tightening mode. What happens is somebody tightens it with a minimum 900 ft.lb. 1" impact and you are trying to take it off with a cordless that has between 700 to 780 in the forward or tightening position

I must admit that the new Milwaukee with 1,000 ft.lbs. tightening torque is getting there. but there is no guarantee that it will remove all 60 outer nuts on the Op's bus

 

[dnschmidt]

Rather than deal with all that what's wrong with using a torque multiplier. These should easily be able to break the lug nuts loose and then go with the 1/2" cordless impact to spin them off. Isn't this standard equipment on most Class A motorhomes?

https://www.amazon.com/dp/B00MI0DOW6/?tag=atomicindus08-20

 

[Diesel Mercedes]

The 18 hour adventure was a failed tag axle wheel bearing. A mobile mechanic had to drive over three hours to get to us. This is the first tire problem on the road.

Some friends of mine have been stuck in Reno for a week with a motor home that needs new front spindles. They had the wheel bearings replaced two weeks ago, but they were not replaced properly and locked up. They should be leaving today.

Sounds like the bearing was put on too tight. Tight bearings and lack of preloadimg will fry bearinga quickly.

 

[Diesel Mercedes]

The vehicle is a Dina Viaggio 1000 coach bus. It uses 11R24.5 tires with the lug nuts torqued to 475 ft lbs. The wheels are stud pilot. The steer tires are BF Goodrich ST230 and the drive and tag tires are Roadmaster RM185. The engine air compressor is a Bendix Truflo 750 that puts out 16.5 CFM @ 120 PSI.

I don't see how any of this is relevant to my original question of if a 110 volt compressor will supply enough air for a 3/4" impact wrench. I currently own two 3/4" pneumatic impacts and would be willing to buy a 1" impact wrench if necessary.

I have a Makita XWT07Z LXT cordless 3/4" impact with 1,250 ft lb nut busting torque that will not budge any of the lug nuts.

Who works on that thing? Seems, like every nut was fastened with an impact until it wouldn't turn.

Better hope to god nothing is warped.

 

[reader2580]

Sounds like the bearing was put on too tight. Tight bearings and lack of preloadimg will fry bearinga quickly.

The bearings had been done by a well regarded shop at least six years before this happened. I'll never really know why it failed as there was a lot of damage. The mobile mechanic was able pull the hub off without removing any nuts or anything.

 

[reader2580]

Rather than deal with all that what's wrong with using a torque multiplier. These should easily be able to break the lug nuts loose and then go with the 1/2" cordless impact to spin them off. Isn't this standard equipment on most Class A motorhomes?

I have a torque multiplier. It takes a long time to remove 20 nuts with a torque multiplier. We also managed to bend several of the budd nuts with the torque multiplier somehow. An impact wrench would take a fraction of the time.

No, a torque multiplier is not standard with Class A motorhomes. Some motorhomes don't even come with spare tires anymore. Most Class A owners would rather wait for roadside assistance than change their own tire.

 

[bczygan]

This wouldn't work?

 

[reader2580]

No, a lug wrench like that will not work with lug nuts torqued to 475+ ft lbs.

 

[bczygan]

Can't install a 240V circuit?

Bill

 

[reader2580]

Generator is only 120 volt.

 

[theoldwizard1]

The on board air system in this thing has no problems running 1" impact wrench. And you seem to have plenty of space to add extra 20 gal air tank for this purpose.

Probably the best suggestion !

Plumb it into the standard air lines, but you need at least a 1/2" outlet and 3/4" hose for your 1" impact gun. This is probably what you want Ingersoll Rand 285B-6 Heavy Duty Pneumatic Impact Wrench with 6-Inch Extended Anvil, 1 Inch over 1,000 ft-lbs Require 120 PSI @ 11 CFM. You might have to wait a minute or 2 between lug nuts for you air system to refill that tank.

Now are you going to buy a torque wrench capable of 500 ft-lbs ?

 

[larryforce]

The new second generation Milwaukee high torque impact has 1400 foot-pounds capability. just saying.

And my first generation Milwaukee 2763 has not failed me on school bus lugnuts (450-550 ftlbs)

 

[AffableCurmudgeon]

It is probably cheaper to just pay for a roadside tire change as needed rather than carry an expensive compressor. I have roadside assistance, but they can take hours or even overnight to get service. I once waited 18 hours in the middle of Wyoming to get help. Nobody wants to go out after hours to the middle of nowhere for what roadside assistance pays.

If it were me, I would just pay the road side assistance guy. For having to wait for the mechanic to show up, because they don't want to come out for what roadside assistance pays, that is very easy to cure: call them and offer them extra money.

 

[reader2580]

Now are you going to buy a torque wrench capable of 500 ft-lbs ?

I already have a Tireman 600 ft lb torque wrench that I bought from a pawn shop online for about $75. This torque wrench is specifically designed for tire work and is the same as a lot of tire shops use. I had it tested by a local tool repair place to make sure it wasn't out of calibration.

 

[reader2580]

If it were me, I would just pay the road side assistance guy. For having to wait for the mechanic to show up, because they don't want to come out for what roadside assistance pays, that is very easy to cure: call them and offer them extra money.

Tire shops often charge $100 to $150 per hour door to door to make a service call. It is cheaper to buy a 1" impact wrench and set up my converted bus to supply air than one service call.

I bought a new (with shelf wear) Wurth 1" impact wrench from an Ebay seller last night for $240. I figure even if still made in China the Wurth impact is better than a generic made in China impact. Wurth isn't just relabeling a generic Chinese impact as their logo is embossed in the metal. I already have the 1/2" air hose and Milton V connectors.