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I've got a shop compressor with a Quincy model 230 compressor head. The tag says the size is 3.5X3. This is an industrial size unit and the head alone weighs about 200 pounds. While having it shipped the shipper did some damage to the unit. The belt pulley on the electric motor is broken and the pulley on the compressor head has 1/4 inch of runout. The pulley on the head is 16 inches in diameter and made of cast iron. As near as I can tell the compressor shaft is not bent. But it doesn't have to be bent much to show 1/4 inch of runout at 8 inches.
My question is do I need to worry about the runout or is this allowable? This thing uses 2 drive belts and I don't want it to start throwing belts off or hammering the bearings out of the head.
Supercab ,I would pull the pulley of the motor and the compressor and verify with a dial indicator that the shafts are not bent. If they aren't you can go from there to get new pulleys.But if the shafts are bent you will have vibration and bearings will go out in a short time.
Just my $.02
This wasn't cheap foreign stuff was it? Just Joking with you !
Hope things work out
Rich
Nope, I think it's that American junk ;-). Quincy is headquartered in Alabama. Not sure where they manufacture though.
Yup, I just realized I'm going to have to put a dial on the compressor shaft. With 1/4 inch runout at 8 inches, it equals 0.156 inches runout at 1/2 inch. I'm not going to be able to eyeball that.
Practcially speaking though, I can get replacement compressor heads for $300-$400. Odds are the shaft cannot be replaced for that. So my best bet will probably be to pull the 16 inch pulley and check it for flat. If it's bent I'll replace it. If not then I'll try to install the pulley and compensate for the runout, then run it till it pukes. Here's to hoping it's just the pulley.
can cast iron BEND ?....dont think the compressor pulley can be bent if its cast.....sure wouldnt use it if by chance it IS possible....might put a hole in something when it comes apart
The pulley has 2 splits with 2 fastening bolts 180 degrees apart. I'm hoping that the pulley just slipped on the shaft and if I loosen the bolts I can realign the pulley. But I'm never that lucky.
I would take the pulley off and check the shaft. No need for fancy instruments to do a quick check. Just rest a long bar of some kind on it, turn the shaft and watch the bar. If it moves up & down, the shaft's bent.
Good idea. I've got a long bubble level. If the run out is 1/4 inch at 8 inches it should be very visible at 2 feet. The only problem will be turning the shaft by hand. I don't want to bugger up the shaft with a pipe wrench and not be able to reinstall the pulley.
If you want to turn the shaft you can grip it with a pair of channel locks up close to the shaft seal. Scars on the shaft in that area will not interfere with the pulley. Besides, it will not take that much effort to turn the shaft. You will not need to grip the shaft hard enough to leave scuff marks.
I have Addressed this problem many times in my life and almost always the shaft is bent. I think if it were mine I would go ahead and run the thing and then decided if it shook too much or not. The chances of interfering with the connecting rods / pistons does not seem likely with only 1/4" runout.
If you have to you will need to remove the F-Wheel and disconnect the rod caps.
Then lay the machine down with the shaft hanging down, ( I have a 3" diameter hole in the center of my work bench just for this ), Remove the rear cover and oil pump ( If equipped ) and extract the crank shaft. Take care to guide it past the rods.
If you choose to do this yourself I would be glad to help in any way I can. Just let me know.