starter motor to turn compressor-not

[cookie monster]

bought an air cond compressor to rig up as an air compressor. unfortunatly the space i had in mind wasnt big enough-bummer.
got me thinking though-why not use a 12v motor to turn the compressor? a friend had an old starter motor lying around, so i grabbed it, bored the front out to take a bearing to support the main shaft. then turned up a pulley for the shaft and got a belt to fit and mounted the starter motor piggy back fashion.
gave it a thourough test tonight pumping into my air receiver. well it works ! but the starter gets mighty hot and starts smoking abit when the pressure gets to about 80psi. had it up to 110psi but very hot ! so unfortunatly will have to put it on the
'well thats a good idea' pile. :cry:
any body got any other ideas how to drive the compressor????
cookie monster

[Steve F]

Spooky, I was discussing this with a mate last week and we decided the starter motor would overheat as it isn't designed to run for long periods, just short bursts. We thought a crappy old winch motor, even a small one might work though.

Cheers
Steve

[jackroov6]

If you dont need much torque from the motor a wiper motor could be used,with a reduction gearing it would run all day long,just like a spit ;D

[Eddy]

since you're into turning, turn up a heat sink for it (?)
Or, you could get a cylinder from an air cooled single cyl bike and press the starter into that.


:-\if it works let me know ;D

[GQtray]

maybe you could mount it off the front diff,mount a pulley in between the diff/driveshaft flanges .crazy yes but it just might work.a pto off the gearbox would be better.

[GQtray]

or mount it to a chainsaw motor or something similiar,and have it as a portable compressor.make the 12v ones look a bit ordinary. ???

[Snofox]

Good idea "cookie monster", but could not possibly last long.
Commendable that your a thinker prepared top try.

A starter motor, as you said was not made to run for long periods. If you read your vehicle hand book, it 'should' say never run the starter for more than 15 seconds without giving it 2 and half minutes cooling time, before running it again.

The reason is the motor does not have cooling capacity (heat sink), but placing one on it would still not work.
They simply get hot because of the massive amps they require to turn a car motor over. Even when not starting an engine, they are still sucking through heaps of amps. It these amps that make the unit so hot.

Another unfortunate about this situaution is, because a starter motor is pulling so many amps, it will KILL your battery fast, and deteriorate the battery usable LIFESPAN dramatically.

A starter motor running in the way you've tried, will burn out anyway. The brushes will pratically melt away from "overunning" or from "Brown Out". Brown out is when the motor cannot get enough power from the battery (getting flat), and the motor strains to get the power, causing overheating.

My suggestions... No idea,
but would try using an old winch motor (as suggested by Steve F), or wiper motor, (geared down, as suggested by jackroov6) as they are both designed for long running. The winch motor is also designed to run under load.

[Twisty]

or mount it to a chainsaw motor or something similiar,and have it as a portable compressor.make the 12v ones look a bit ordinary. ???


The chainsaw idea sounds pretty sweet to me, it'd be awesome!! 2 stroke air compressor ;D

Someone has got to build one of these, if I could I would!!

[GQtray]

hmm i have got a spare chainsaw without a bar in the shed,and a couple of aircon pumps....................

[Snofox]

hmm i have got a spare chainsaw without a bar in the shed,and a couple of aircon pumps....................


Sounds good.
Go to it!!!

[FJ60]

2 stroke is no good cost you hundreds to run it as for petrol models i no there are 24 litre 4 strke petrol compressors.

[cookie monster]

had a look around 'u-pull it' the other day. the smallest air-con compressor i found was on an 87 barina. approx 165 long (compares to 220 for the one ive got).
i recon this WILL fit where ive got the space above the alternator. will have to find one off the shelf to try in the car before i buy(should have done that in the first place!!!!!!!!!)
ill keep u posted
cookie monster