Dual motors on an air compresser

[ChiScouter]

Ive been a cheap bastard forever and have refused buying a big vertical tank compresser figuring a used one for cheap was just around the corner. I have recently started building up parts to build it myself. First was a gas powered 3 cyl 2 stage compresser with a bad gas engine for 40 bucks, then last week I got a 60 gal vertical tank for next to nothing . I have 2 ea 3 hp 3450 rpm cheap ass but almost new compresser duty motors. 3 hp will not turn that 3 cyl 2 stage pump. I am thinking about mounting the 2 motors next to each other on a plate with a jackshaft mounted above them. I would use one belt across the 2 motors and the jackshaft, and a second belt to go from the jackshaft to the pump. I know it is more than a bit hokey, but I have the motors, pressure switch, the jackshaft and may even have most of the pullys. I haven't yet researched the cfm of the pump but so far I haven't found any tags on it. The engine was a big old Kohler I figure around somewhere between 7 and 9hp.

Why won't it work, or why shouldn't I do it?

[Kartracer55]

Just go on Ebay and look for a big motor.

I have heard of guys running 2 pumps from one motor... What they do is get, say a big 10hp 3 phase deal and rig 2 pulleys to it and use it to drive two 5hp compressor pumps.

I dont know for sure if it would work or not but if you say it was a 7-9hp kohler than chances are a 5hp or so electric motor will drive it. All gas compressors use engines larger than thier electric equivalent because the engines dont develop thier full rating everywhere in the RPM Range.

As to what your talking about, Im sure you COULD possibly rig something up but who knows if it would actually work, ya know? You would really have to mess around with pulley sizes because your going to want to slow down the pump to what its rated speed but still ensure the electric motors can provide enough torque. My vote is just go and find a bigger motor, but who knows it would be pretty cool to see actually

jim

[Flashover Mfg]

I would be concerned that the motors would turn at slightly different speeds and may fight each other.

[ChiScouter]

I should have mentioned that both of the motors are the same brand and model. One has never been used, and the other has maybe 50 hours on it in a unstressed application. The thought of slightly different rpm's under load does concern me

[80j5]

dont sweat the rpm's it will be fine just use the same size pulleys on the motors. id run them in a Y configuration though with the motor on the ends and the pump in the middle

[ChiScouter]

dont sweat the rpm's it will be fine just use the same size pulleys on the motors. id run them in a Y configuration though with the motor on the ends and the pump in the middle


I hadn't thought of that, thanks:beer:

Upon further thought on your idea I am more likley to mount the 2 motors to the tank and raise the pump up just high enough to clear the bottom pully on the pump