Pneumatic motor stalls on start

[ports394]

I have a small 0.33 hp Gast air motor. I've uncoupled it from the pump so I could work on it.

if I start the air to the motor, it just blows through. but if i jog the shaft just a little, it picks up and will start working. Once I stop the motor, again same problem, air just blows through.

Is it possible to fix this thing?

 

[MikeHalloran]

The vanes are stuck, or sticky, or maybe worn.

Try flushing it with a solvent/oil mix, or Marvel Mystery Oil straight.

If that doesn't work, you may have to disassemble it to see what's going on.


Mike Halloran
Pembroke Pines, FL, USA

 

[ports394]

Mike,

Thanks. I used some ethanol to dry out any water in the veins. Then purged some air through it, and let it dry totally. And then just kept dosing large amounts of air lube oil with a syringe and manually turning the shaft. Seems to work just fine now and doesn't stick!

thank you.

 

[NuclearNerd]

I had (have) a similar problem.

http://www.eng-tips.com/viewthread.cfm?qid=305548&page=1

The consensus was stuck vanes too. You'd think air motor manufacturers would have come up with a more reliable way to force the vanes out at startup.

 

[ports394]

From what I've been reading, ites an issue with the starting torque. It's really low on air motors, and any humidity/moisture issues mess up the veins easily.

In my case, I had to use a pipe wrench and vice to manually turn the shaft on a 1.7 hp Gast air motor.. but as I got it moving, I kept putting oil into the air inlet and turning it. I let it penetrate overnight, and started it up the next day, and it worked.

Lesson learned.. be much better about lubricating air motors.

 

[dgallup]

I used to run diesel engines on dynos. We used air motors to start them. Any time the air motor would not work I'd dump a pint of diesel fuel in the air supply line. Worked like a champ but made the floor rather slippery.

The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[CRG]

Do you have a air dryer that works?
Do you have a in line oilier/lubricator?