I need some help ... I have reassembled my generator with new bearings , brushes , etc. ... and checked the windings for any shorts .... checked the armature .... but when bench testing it for motoring as I put 6 Volts to it the armature shaft freezes up..... you can not turn it buy hand .... no matter where I rotate the brush plate the armature shaft is locked up ...... HELP .... Joe Gallagher ..firstname.lastname@example.org
Are you lifting the third brush off the armature when trying it?
Cameron tried to answer last year
Did you cross the stator wires?
In answer to the questions: The third brush is not even installed yet. I also crossed the field coil wires
Here is the story. I have polished the commentator, installed new bearings, checked the armature with a digital ohm meter, checked the coil leads for any shorts to ground,
checked the coil leads for continuity, replaced insulator for the third brush, crossed the coil wires and installed one on the Third brush holder and one on the grounded brush holder.
As soon as I installed the brush in the UN insulated (grounded) holder and then installed the brush in the Insulated brush holder the insulated brush holder goes to ground!!! As well as the Third brush holder. Is this suppose to be happening and if not what am I doing wrong!!! As posted previously when bench testing for motoring the armature just freezes up can not turn it no matter where you turn the brush plates. HELP
If I follow correctly, your insulated brush is contacting the commutator, making a circuit through the armature windings, then connecting through the commutator, with the un-insulated brush, which makes a circuit to ground. That's why your insulated brush is going to ground.
Did you test the armature on a growler??
If the growler showed a good armature try to move the total brush bridge left or right and see what happens. Maybe you were lucky and set the brushes on the neutral spot.
Jerry... That is what I see is happening also and it also is putting a ground back to the main terminal on the generator ... is this normal ??? It does not seem correct .... Like I have said when I put 6 volts to the terminal bolt the armature just freezes up, like it is a dead short???
Joe, by rereading your first post I see you already tried to move the brush bridge.
Did you test the field on magnetism. With a compass you should find N S N S as you set 6V over the field coils. Use a 18W test light while doing this. Pay attention to connect the third brush connection to the + battery.
A few times I have seen the field wires not crossed.
Andre, I do not have a growler, I have been checking the armature with a digital ohm meter. I have tried the field wires crossed and uncrossed with no different results.
I am not understanding about the magnetism test. What I am I exactly testing or the procedure. Can you explain it differently.
Thanks for the help
I rebuild Model T generators every day. I am willing to help with yours, but not here in public. Too many opinions and this has to be done logically with no jumping around like a grasshopper.
If you wish give me a call; If you will do exactly as I ask we can find out what is wrong and fix it.
I will be in my shop 10am to 4pm EST tomorrow.
here a link I set on dropbox with some information about the repair of a generator.
All the info and more is in the MTFCA Electrical system book. The compass test is in the starter part but it work for the generator.
First!!!! CALL Ron, He will walk you, step by step on an easy way, through your generator problem.
Take Ron up on his very generous offer. He knows his stuff.
As Hal suggests, speak with Ron. You WILL get your problem solved. But, once things get figured out, please let us know what he cause was.
Ron IS the man...
Ron is being very generous in offering his help. I for one would like to see Ron post his procedure here on the forum. It would help others that may have this problem. After all isn't that what the forum is all about.
The "path to ground" that you are seeing is WHY you have to have a cutout in the system to remove the discharge path once the generator stops turning. Call Ron!
I know why Ron does not wish to engage the forum and I don't want to either. Too many "suggested parts replacements" occur before any problem is actually located and that just adds variables at best or additional problems at worst. Neither Ron nor I believe in replacing parts to see if that might fix a problem. Usually it only adds another variable to the mix and in the end there are more problems and variables than when the discussion started. It isn't that we don't want to help but just that there are too many people with their own ideas and it is impossible to provide competent tech help using a committee.