# Re using motor from old direct drive compressor



## roxanne562001 (Feb 5, 2012)

Hi all I am looking for some help. I have an old Campbell Hausfield Model # WL350002AJ air compressor. The compressor part went bad and it will cost more to repair the air pump then I can buy a new one for. I thought I might be able to use the motor for something else in the shop but I can't seem to figure out how to get the direct drive crank shaft off of the motor shaft. The parts break down diagram shows a set screw but I can't find one Maybe some one on this forum has worked on one. I am attaching a link to a pdf break down from the CH site http://www.chpower.com/IMAGES/pdfs/manual04/U000337_0301.pdf


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## DaninVan (Jan 1, 2012)

Hey, Roxanne; from the drwg. it looks like it _should_ on the cam edge that drives the piston(?)...
Way too many times the engineering changes but the documentation doesn't.
There should also be a flat or a keyway on the arbor. That's the other likely place to find a setscrew hidden. 
Just out of curiosity, what's actually wrong with the compressor? What are the symptoms? Is it 'oilless'? (sp?)


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## roxanne562001 (Feb 5, 2012)

Yes it is oil less. The reed valves broke off and fell in and wrecked the piston and Cylinder the head looks messed up too. I priced the valve kit and piston and cyl and it is a bit over $120.00 plus shipping if. I can use the head over again. I just don' think it is worth it. The next one will be a belt drive with oil.


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## roxanne562001 (Feb 5, 2012)

Hi DRWG Do you think it could be pressed on?


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## Dmeadows (Jun 28, 2011)

It could be pressed/cemented on. If you can't find a set screw, its even likely.

Wow, I didn't know those cylinder kits had got that expensive!:sad: I used to rebuild quite a few of those. By the way, if used for paint spraying, those oil less compressors need to be in clean air. Paint fumes will take those out pretty quickly depending on what you are spraying!


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## DaninVan (Jan 1, 2012)

Roxanne; save the tank! You can splice it in at the end of your air lines...it'll double your stored air capacity. Like having a 40 gal. instead of a twenty. That should help with jobs like sanding.


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## rwl7532 (Sep 8, 2011)

Sears used to carry Campbell Hausfeld. Have you tried there?


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## Dmeadows (Jun 28, 2011)

rwl7532 said:


> Sears used to carry Campbell Hausfeld. Have you tried there?


Ralph, can't speak for Roxanne, but the parts at Sears are listed as "requires a tech to order". I think(just kinda guessing really) that is because they bolts need to be torqued to spec on those or repeat failure is common. Especially on the twin cylinder pumps. 

Sears was the was the first place I looked! I am a retired employee of Sears.


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## Willway (Aug 16, 2012)

I also have one that has bit the bullet. I have looked at mine after trashing the pump. I would almost bet they are a shrink fit. Heating it to get it off would probably destroy the front bearing. They usually induction heat these parts and just place them on the shaft. If you can see the end of the motor shaft you can pull it with a puller and a bearing plate. if you cant see the end of the motor shaft consider drilling the eccentric crankshaft, then pulling. I use mine as an auxiliary tank for now.


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## Dmeadows (Jun 28, 2011)

DaninVan said:


> Roxanne; save the tank! You can splice it in at the end of your air lines...it'll double your stored air capacity. Like having a 40 gal. instead of a twenty. That should help with jobs like sanding.


That also doubles the run time of the compressor. Not being designed for that, many of the less expensive systems will overheat and shorten the lifespan of the pump. I knew a guy that had 3 60 gal tanks on his air system.. couldn't keep pumps on that thing!:sad::sad:


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## DaninVan (Jan 1, 2012)

Duane; yes, but that's a bit extreme...we're only talking about 40 gal here, not 180.
When I'm using my jitterbug, the compressor is pretty much constantly running. Unless I stop sanding for a bit; I'd rather have the reserve tank to even out the pressure in the system. 
My old CH belt driven (oil type) compressor must be at least 25-30 years old. I just rebuilt it last year...all the controls, valves etc., the motor and compressor were fine.


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## Dmeadows (Jun 28, 2011)

DaninVan said:


> Duane; yes, but that's a bit extreme...we're only talking about 40 gal here, not 180.
> When I'm using my jitterbug, the compressor is pretty much constantly running. Unless I stop sanding for a bit; I'd rather have the reserve tank to even out the pressure in the system.
> My old CH belt driven (oil type) compressor must be at least 25-30 years old. I just rebuilt it last year...all the controls, valves etc., the motor and compressor were fine.


With a 25-30 year old compressor, yeah you'll probably get by with it! Newer stuff, used only occasionally, you may get by with it. Used for sanding 8 hours a day 5 days a week.... ???? Doubling the volume will double the run time. Tripling the volume will triple the run time(the case with the 3 60 Gal tanks... also belt drive oil type!). Just want to let people know that there is the possibility of a downside to doing that! Most low end compressors are *not* designed for any where near 100% duty cycle, and the more tank capacity you add, the closer they get to that!

As always... YMMV!

PS.. It's not the 40 vs 180 thing. it's the doubling or more what the system was designed for that can cause problems! The original tank on the system I was speaking about was 60 gal, by the way.


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## MikeMa (Jul 27, 2006)

My pancake compressor is going on 10 years old now. The manual is very specific about making sure the motor only runs 30 minutes out of every hour. This is because the motor and compressor generate a lot of heat (which why you get water in the tank), and if the motor runs too long it will over heat. Each time the motor overheats it shortens the life of the motor to the point it will finally give out. Adding extra tanks to it is fine, as long as you are careful with how much the motor is running.


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## Dmeadows (Jun 28, 2011)

NiceG316 said:


> My pancake compressor is going on 10 years old now. The manual is very specific about making sure the motor only runs 30 minutes out of every hour. This is because the motor and compressor generate a lot of heat (which why you get water in the tank), and if the motor runs too long it will over heat. Each time the motor overheats it shortens the life of the motor to the point it will finally give out. Adding extra tanks to it is fine, as long as you are careful with how much the motor is running.


Agree, except I have seen many more compressor pumps fail, than motors. Talking belt drive oil units here. Got several CH compressors setting in the shop right now, awaiting rebuild. One of these days I do intend to get to that, but it's rather low on my todo list. 

Wouldn't give 10 cents for oilless units, myself.


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## DaninVan (Jan 1, 2012)

Duane; all things considered, I'm probably doing more damage to the motor by running it to it's max on 120V rather than doing the switch over to 240V (it's dual voltage). It's just too convenient being able to plug it in almost everywhere... 
Anyway as I say, after 3 decades I've got nothing to complain about.


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## Dmeadows (Jun 28, 2011)

Dan, as long as you don't have excessive line voltage drop due to the higher amperage on 120V, that really should not adversely affect the life of the motor! In 35 years as a service tech, I can still count the air compressor motor failures I've seen on one hand!
I have replaced or rebuilt many, many CH compressors though. That said, one of the biggest issues is the head gasket on many of them is a horrible design! Not enough material for the pressure.. 90% blow in exactly the same spot. I should say that most of those were 60 Gal upright units.

I agree you can't complain on 30 years! Hope it keeps right on running for you, Dan!


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## DaninVan (Jan 1, 2012)

Duane; I'm pretty sure the motor has 4X the torque at 240V (over120V).
I could be wrong, but I think the calc. is something like...
_'The power calculation (in Watts) is really all you need to do. Voltage squared, divided by resistance. Resistance stays the same, so power quadruples when voltage doubles. If the motor spins at the same speed, then torque should effectively be linear with power, aside from the extra heat created in the components from the higher current._


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## Dmeadows (Jun 28, 2011)

DaninVan said:


> Duane; I'm pretty sure the motor has 4X the torque at 240V (over120V).
> I could be wrong, but I think the calc. is something like...
> _'The power calculation (in Watts) is really all you need to do. Voltage squared, divided by resistance. Resistance stays the same, so power quadruples when voltage doubles. If the motor spins at the same speed, then torque should effectively be linear with power, aside from the extra heat created in the components from the higher current._


No,no,no. Power = volts x Amps(P=EI) or E squared over/R. Converting the motor to 240V, drops the current to 1/2 of what it is at 120V, thus less line voltage drop for the same gauge wire, but the power(Watts) is the same. May have a little more start torque, but that's about it. Oh, and the resistance doesn't stay the same either as the windings are configured in series instead of parallel! And in a motor, winding resistance is only a portion of what limits the current! It will limit the start surge, though.

That's a rather simplified explanation but hopefully will serve it's purpose.


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## JCJCJC (May 15, 2012)

If I may return to the OP's question - have you taken off the screw numbered 17 in the drawing, and possibly also extracted the pin numbered 18?
It's hard to believe that the grubscrew No 13 isn't there - try cleaning around the circumference of the cam with wire wool or smooth sandpaper to see if it can be revealed. If the cam is held by an adhesive, it's almost a convention in mechanical assembly that the adhesives used will yield with heat - like titebond in woodwork. There HAS to be a way to get it off!


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## gmercer_48083 (Jul 18, 2012)

I don't think you can re-purpose the motor because the fan is attached to the crankshaft and would be required to cool the motor. So even if you got it apart you would still have to re attach the fan. that would render the end of the motor shaft useless. Toss it!


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## mikea47641 (Sep 23, 2015)

Volts times Amps = Watts


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