[Graflex45]

Originally Posted by ol'George

I hesitate to post this as it would be obvious, but is the armature showing signs
of rubbing on the pole shoes?
Another thought:
If you removed the regulator wire from the field terminal, then the Generator would not produce a charge as there is no excitation, unless the field STUD is no longer insulated and is grounded to the case where it comes through it,-------
Just something to check.
Also check the condition of the commutator for any signs of the brushes arcing,
as each segment should look the same compared to each other.
Also check to see that the armature windings where they are soldered to the commutator, have not been overheated and thrown/melted the solder out of the connections, that would indicate a bad armature.

Also check that your brush wires are not touching anything they shouldn't
like the through-bolts or touching the case.
Heat is either rotational friction or excessive electrical production/ground.
You mention installation of ammeter, did you wire it correctly?
They are not an voltmeter where one side is grounded!!
they are a "pass threw" as in cutting a wire and hooking each end to the ammeter terminals.
Edit:
I just looked at your profile, sorry,
I didn't know you were versed in electronics.

Armature spins freely with no contact on the shoes
Yep ammeter connected properly, initially things were working and by grounding the field terminal could force it into charge mode and the engine reacted to load and the ammeter showed charging current.

See my above post, this all happened after I reconditioned the generator (new sealed bearings) and turned down the commutator. the new brushes I used sandpaper to make sure they matched well to the commutator and cleaned them off. I checked the Armature side brush to make sure it was well insulated, the ground side brush had a good ground. There wasn't much room for the brush connecting wires but with the insulating sleeving it looked like they where fine and weren't showing as grounded.