Aro Pneumatic Drill Doesn't Spin

[ericc]

Hi Davidh. It is the first one. There is a roll pin going all the way through the air motor. It indexes both the top and bottom end cap. I'll have to look for the air channels that lift the vanes.

 

[davidh]

The last large shop I worked in used air power drill motors for field work. They use a oil designed for air tools. Little cans look like Liquid Wrench style with a pointed top. Put a few drops in the bottom of your air motor before connecting the air hose

thats is a good idea too, however, if you remember to oil the hell out of the tool BEFORE you put it away, it will retain OIL and not moisture, for however long it sits before you use it again. that has been my suggestion since my conversation with the chief engineer from Ingersoll Rand, many years ago.
i recommended Marvel Mystery Oil, with a tad amount of automatic transmission oil added to it. in my opinion it was superior to "air tool oil".
jist sayin'

 

[ericc]

I think I get it now. The front end piece has a groove which directs air to an inner arc which will cause the air to push the vanes out.

The picture shows the air path as well as the hole for the indexing pin. Air flows up two axial holes in the motor shell into the outer groove.

I still don't know why it doesn't work. Maybe the vanes are too worn. They are below the surface of the rotor.

 

[davidh]

nice picture. is this the front or rear end plate ? (the rear is the end toward the air inlet ) take pictures of both end plates and both ends of the motor cylinder. there are a few other things that need to be verified. also a photo of the outer end of the housing, aim the camera toward the bore of the housing. there is no magic, i promise.

 

[davidh]

here is a snapshot of a motor from a die grinder. taken with the "rear" end plate removed and flipped over along side the cylinder assembly. notice the oblong hole in the end plate, thats where the incoming air comes thru and notice the funny looking mating part of the cylinder. most all cylinders are like this in some form or other and often when diy's take the motor apart, the cylinder gets reversed (end for end) and this "air inlet " section on the end of the cylinder is on the wrong end.
if push comes to shove, send it to me and i will make it run, probably have new vanes for it here also. . . . .

 

[kd4gij]

thats is a good idea too, however, if you remember to oil the hell out of the tool BEFORE you put it away, it will retain OIL and not moisture, for however long it sits before you use it again. that has been my suggestion since my conversation with the chief engineer from Ingersoll Rand, many years ago.
i recommended Marvel Mystery Oil, with a tad amount of automatic transmission oil added to it. in my opinion it was superior to "air tool oil".
jist sayin'

I like Marvel Mystery air tool oil.

 

[davidh]

i do the regular Mystery oil like i said but i mix it in bulk for resale. . . . i think its cheaper.

 

[ericc]

Here are more pictures.

 

[ericc]

The first is the back end where the air enters. The second is the rotor. The third and fourth is the back and front of the cylinder. the front has the short roll pin. It can't be flipped because the front cap won't fit due to the blind hole.

 

[davidh]

is the rotor removable from the rotor shaft ? some of the more expensive ones are built that way
do you have a model number of the tool ? probably not.
wanna to send it ? no charge, no guarantee ?
should fit in a "usps small flat rate box" for less than $6