# Craftsman eccentric pin to motor shaft connection question



## Fitzcarraldo (Oct 8, 2019)

I have a 25 year old Craftsman/Devilbiss twin cylinder oil-less 6 HP 33 gallon compressor (model 919052930). Bought it new, and for the most part it has been adequate for my needs except for when running a zizz wheel (which I don't do very often anyway). 6 months ago when I flipped the pressure switch to turn it on it fired up with a hellacious amount of rattling and banging. Turns out it had broken both connecting rods. I've been using my smaller portable compressor for the last 6 months, but finally got around to taking a closer look at the Craftsman. The parts I would need aren't available for the model anymore. After giving it some thought I decided I might just take the motor and remount it on a new top plate to turn a belt driven 3 HP Campbell VT4923 compressor pump I can get new for $200 online. My motor is a 230 volt AO Smith rated at 14.0 amps, so seemed to be capable of turning the 3 HP pump. If not I figured I could always slow it down some with a smaller pulley on the motor. The trouble started when I began breaking everything down to make sure that the motor was indeed compatible shaft wise with a new drive pulley. I don't know much about motors from a build standpoint.....I've mostly just matched them up and replaced them in blowers, fans, and such. Never dealt with one that didn't have either a keyed or flatted shaft. The first thing I noticed on the one off the Craftsman was that there isn't a bell on the drive end. The oil-less pump frame serves as the bell so to speak. I figured I could probably come up with a bell at Grainger or a motor supply place. But then after I took the connecting rods and counterweights off of the eccentric shaft/pin I noticed it was attached to the motor shaft in a way that I don't quite understand. After looking at some exploded parts diagrams online for my model as well as some similar 2 cylinder Devilbiss models I'm beginning to think that the shaft is some type of proprietary affair that is made for direct-drive oil-less compressors only. My only hope was that this odd-looking 1 inch shaft with an eccentric pin hooked into the side of it and held in place by the counterbalance which I imagine is pressed on to the shaft.....I hoped that maybe this whole assembly was somehow mounted to a conventional 5/8 inch shaft back behind the pump frame...and that I could then extend the shaft far enough out to put a pulley on it with the use of some type of coupler. But the more diagrams I see online the more I doubt it. I was hoping someone on here might have some insight into this, possibly having taking one apart themselves. The closest motor shop is 35 miles away and I just wanted to avoid the trouble of driving there only to have them laugh and say there's nothing you can do with this motor like you want to do.


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## Fitzcarraldo (Oct 8, 2019)

Some screenshots of the parts involved (52 and 53):


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## Fitzcarraldo (Oct 8, 2019)

I see that those screenshots aren't viewable for some reason, so here are the links to them instead:

https://www.partselect.com/Models/9...f&Position=1&mfg=Craftsman&Type=Washer&Mark=1

https://www.partselect.com/PS100425...=919152930&ModelNum=919152930&ModelID=6083942

https://www.partselect.com/PS100425...=919152930&ModelNum=919152930&ModelID=6083942


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## stevon (Mar 5, 2019)

*Compressor Conversion*

Fitzcarraldo

So as far I can ascertain, you want to use the Sears ("6 HP" bogus claim) motor to power a regular pulley driven pump as a 2 to 3 HP motor which is in truth is about as much as this motor actually produces. In theory that sounds like a possibility, but it won't be easy unless this motor started as a regular motor and was somehow changed for this specific design. With a machine shop (Removing or cutting off the extra aluminum and cylinders for belt clearance) and a welder it could be done but why would you go that route? The shaft is probably bent and the bearing might have taken damage. For all that work You could instead have my 3 hp Smith & Jones compressor duty motor for just the shipping costs. Sold by Harbor Freight it actually is an overrated 2 HP motor that you can pull 3 HP for an hour or so before it overheats. The other question is how big is the platform on the 33 gallon tank?

For all the effort and engineering involved you could just buy a compressor and be on your way
https://www.ebay.com/itm/Craftsman-...061388?hash=item1f01da2b8c:g:5MYAAOSwjyZdgRgD 
I myself, like to tinker so in my case I would prefer to waste time and money to build something to use. But I do not follow the most practical/cost effective and direct solution. I have the tools, skills and a few extra parts to have fun with this stuff as a hobby. But that is my choice, a practical solution is to buy a suitable compressor and move on (no fun IMO).

Stephen
QUOTE=Fitzcarraldo;67242]I see that those screenshots aren't viewable for some reason, so here are the links to them instead:
t 
https://www.partselect.com/Models/9...f&Position=1&mfg=Craftsman&Type=Washer&Mark=1

https://www.partselect.com/PS100425...=919152930&ModelNum=919152930&ModelID=6083942

https://www.partselect.com/PS100425...=919152930&ModelNum=919152930&ModelID=6083942[/QUOTE]


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## stevon (Mar 5, 2019)

Fitzcarraldo,

There is the tankless option as well to bolt on or weld onto your tank:
https://www.ebay.com/itm/Speedaire-...019396?hash=item41cd58be44:g:bX8AAOSwrdBZmY3M

https://www.compressorworld.com/r-s...-stage-base-mount-115-230-v-1-phase-br3f.html

https://www.alibaba.com/product-detail/Base-plate-3-piston-air-compressor_60616131639.html

https://www.alibaba.com/product-det...2700.7724857.normalList.11.bafe5706cwygO1&s=p

https://www.alibaba.com/product-det...m=a2700.7724857.normalList.115.bafe5706cwygO1







stevon said:


> Fitzcarraldo
> 
> So as far I can ascertain, you want to use the Sears ("6 HP" bogus claim) motor to power a regular pulley driven pump as a 2 to 3 HP motor which is in truth is about as much as this motor actually produces. In theory that sounds like a possibility, but it won't be easy unless this motor started as a regular motor and was somehow changed for this specific design. With a machine shop (Removing or cutting off the extra aluminum and cylinders for belt clearance.) and a welder it could be done but why would you go that route? for all that work You could instead have my 3 hp Smith & Jones 3 HP normal motor for just the shipping costs. Sold by Harbor Freight it actually is an overrated 2 HP motor that you can pull 3 HP for and hour or so before it overheats. The other question is how big is the platform on the 33 gallon tank?
> 
> ...


[/QUOTE]


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