Starter generator problems

[Graflex45]

I the armatures out of both starters i got and carefully filed and sanded the commutators smooth on the lathe. I put the one from the parts unit which looked to have the least wear in the generator body that was original to my tractor (with checked and rewrapped coils). I put 2 analog voltmeters on the tractor, 1 hooked to the generator armature terminal, and one hooked directly accross the battery. It started fine, initially it looked like the generator was outputting ok, but when i tried to manually short the F terminal to ground to make it charge nothing happened on the ammeter. I thought maybe the regulator is bad (which i checked and readjusted on the bench). I bought a new old stock on on ebay so I swapped that regulator in, still no making it charge. Also observed the voltage on it changed a lot when throttling up and down.
So i took the tested good generator i had ordered (cleaned commutator, new brushes and bearings, only cleaned the inside manually with a brush and wiping off look carbon and gunk with shop towels) reassembled it and put it on the tractor with the meters the same and the new old stock regulator. Started the engine great. Voltage on the A terminal steady and doesnt change throttling up and down. Grounding F got a strong charging current back to the battery and after running it for 20 min the battery charged up to the proper voltage.
I guess the field coils are internally shorted and causing issues? I cant see it being the Armature terminal coil because that is a heavy enough winding I could see the insulation between all the turns and it runs with enough torque when starting?
The coils from the 1101970 gen look like they are wound in the same direction as the other generator coils, are they both incidental replacements for the generator that was originally on the cub?

[ol'George]

Here ya go, its been 65 years or so since I undercut the mica on an armature after I turned it.
this is how its done.
I still have a brass jaw armature chuck with my lathe tooling.
https://www.youtube.com/watch?v=YRy9gS47HMo

[Graflex45]

Originally Posted by ol'George

Here ya go, its been 65 years or so since I undercut the mica on an armature after I turned it.
this is how its done.
I still have a brass jaw armature chuck with my lathe tooling.
https://www.youtube.com/watch?v=YRy9gS47HMo

Thanks for the link but mica in the commutator is not an issue on any of them. I used a hacksaw blade on the first generator armature to clean it out and there is plenty of space on the other 2 I got.
The problem lies somewhere in the stationary coils on the poles.

[green407]

Originally Posted by Graflex45

I the armatures out of both starters i got and carefully filed and sanded the commutators smooth on the lathe. I put the one from the parts unit which looked to have the least wear in the generator body that was original to my tractor (with checked and rewrapped coils). I put 2 analog voltmeters on the tractor, 1 hooked to the generator armature terminal, and one hooked directly accross the battery. It started fine, initially it looked like the generator was outputting ok, but when i tried to manually short the F terminal to ground to make it charge nothing happened on the ammeter. I thought maybe the regulator is bad (which i checked and readjusted on the bench). I bought a new old stock on on ebay so I swapped that regulator in, still no making it charge. Also observed the voltage on it changed a lot when throttling up and down.
So i took the tested good generator i had ordered (cleaned commutator, new brushes and bearings, only cleaned the inside manually with a brush and wiping off look carbon and gunk with shop towels) reassembled it and put it on the tractor with the meters the same and the new old stock regulator. Started the engine great. Voltage on the A terminal steady and doesnt change throttling up and down. Grounding F got a strong charging current back to the battery and after running it for 20 min the battery charged up to the proper voltage.
I guess the field coils are internally shorted and causing issues? I cant see it being the Armature terminal coil because that is a heavy enough winding I could see the insulation between all the turns and it runs with enough torque when starting?
The coils from the 1101970 gen look like they are wound in the same direction as the other generator coils, are they both incidental replacements for the generator that was originally on the cub?

With your "New" generator and regulator on the tractor, you said "Voltage on the A terminal steady and doesnt change throttling up and down"
What was the voltage? Sometimes it takes about 15 minutes for the generator to reach 13 volts, even with the engine at WOT.

It defiantly sounds lie it was the field windings on the old generator.

[Graflex45]

Originally Posted by green407

With your "New" generator and regulator on the tractor, you said "Voltage on the A terminal steady and doesnt change throttling up and down"
What was the voltage? Sometimes it takes about 15 minutes for the generator to reach 13 volts, even with the engine at WOT.

It defiantly sounds lie it was the field windings on the old generator.

The needle on the voltmeter at the generator terminal wanders up and down a bit, i cant remember exactly but I think from 12-14V. The voltmeter on the battery started a little above 12 and got to just below 13 after running for about 20 min. The generator voltage stayed pretty contant even when i went to low throttle. With the old generator the voltage went way down to about 6 volts when I went to low throttle.

[Graflex45]

Is anyone very knowledgeable about delco generator parts here?
I've fully disassembled the original generator on my tractor and the for parts one that ended up being a cw spinning unit. The coils from the CW unit I can tell from powering with a bench power supply and using a compass needle that the cranking coil and the field coil are wound in reverse of the ccw coils from the generator originally on my 70. I can actually probably change how the wires connect to the field winding so it will have the same polarity as the ccw unit to use them since i was going to rewrap the coils anyway.
The question I need answered is are the armatures the same for both rotation generators? The cw rotating unit looks like the armature is a relatively modern replacement that has half the number of commutator contacts and had virtually no wear on it. The previous one probably was replaced because the pole shoes show wear on the pulley end from a worn out bearing on the pulley side.
I'm stripping the paint off all the parts and painting everything with ceramic black engine paint

[Graflex45]

Ok so I finished rebuilding one complete unit from parts.
I have to take the poles and coils out of the unrestored working one to finish rebuilding the body of the generator that was originally on the tractor. My only question is if the armature with the fewer commutator sectors will work the same as the other one. Looking up replacement armatures on ebay the sellers list both CW and CCW units that they replace, so It should work fine?? From rewinding the coils i figured out the difference is the polarity of the windings (cant reuse the series winding, was able to switch polarity of the leads on the field coil and use it in the rebuilt unit)
Put voltmeters on both battery and armature terminal. Analog voltmeters were showing about 14V on both. could see the voltage wobble a bit as the governor dwelled a bit up and down. when i throttled down the voltage stayed the same and was more stable as the rpm was more steady at low speed. After about 20 min when I throttled down and idled a little while before cutting it off the voltage of the battery was stable. I even double checked the accuracy with my digital meter, the more recently calibrated meter showed it was 13V.
The body of the generator got warm much more slowly as the heat from the bearings spread from the end plate to the body. It does get warm but it seems the bearings are more of a normal amount of heating.

[LarryW]

I cant help more then everyone already has but if you buy those ones of ebay for like $120 or probably more now. Make sure every thread hole or anything you are not using gets sealed. I used black rtv because the case is black. But I have ruined 1 of them with water getting inside and another I was able to save with cleaning. The one I saved I think water came in from the end caps? This is from sitting a year or something outside unused. My 2 cents... Good luck getting yours figured out though!

[Graflex45]

Originally Posted by LarryW

I cant help more then everyone already has but if you buy those ones of ebay for like $120 or probably more now. Make sure every thread hole or anything you are not using gets sealed. I used black rtv because the case is black. But I have ruined 1 of them with water getting inside and another I was able to save with cleaning. The one I saved I think water came in from the end caps? This is from sitting a year or something outside unused. My 2 cents... Good luck getting yours figured out though!

I was looking at the eBay listing because I can't find any Delco parts list that show what the parts would be for the 1101970 CW generator. If the people selling the new armatures list the armature that looks like the one that came out of it as being a replacement for starters that rotate both CW and CCW (seller lists the new armature as a replacement for 1101966 as well as 1101970) then it should be useable to complete rebuilding another unit. (So I have 2 working units)
When I finish with both of them I will put a little rtv in the notch in the end so water want get in. The 70 lives in a shed so it won't have any problem with being weathered.
I stripped all of the case parts and used a high heat ceramic low gloss paint. A thin layer of paint so It conducts heat away better and flat black to increase radiation, any little improvement to help it shed the heat.