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picture quiz of generator armatures

Posted: Mon Jun 07, 2021 6:21 pm
by Jim
Hi Everyone

I've been away from posting for a few weeks and have been driving my new to me T. I'm about 200 miles into my career now and still feel a little nervous about the centre position of the clutch as I've driven standard all my life and by instinct I like to shove that clutch to the floor for stopping.

Any way that's not what I came to talk about today. I had my wife take two generator armatures to a starter and generator repair shop today for me.
I was sort of hoping that they would tell me I had two good ones. When they got home I only had one that they put on the growler because at a glance the tech said the other was no good. The one he tested passed.

So, for the fun of it I thought I would post a few pictures here of the two armatures and see if people would tell me what was so obviously wrong about the one he wouldn't even bother testing. The one with bearings on both ends was in my car and was removed today so it has some oil on it. The one with only one bearing on it was in my spare parts inventory.

After I've seen a couple of posts about each ones condition I'll fill people in on which one passed the growler test. Thanks for looking. jim
20210607_armature1.jpg
20210607_amature2.jpg
20210607_armature3.jpg

Re: picture quiz of generator armatures

Posted: Mon Jun 07, 2021 6:24 pm
by RajoRacer
Someone got a bit overzealous with a prick punch to help "tighten" the drive gear !!!!!

Re: picture quiz of generator armatures

Posted: Mon Jun 07, 2021 6:26 pm
by Bill Dizer
Bottom one in the last photo appears to have thrown a commutator segment out, which would ruin it?

Re: picture quiz of generator armatures

Posted: Mon Jun 07, 2021 6:36 pm
by speedytinc
commutator on the pricked one may have gotten hot & thrown solder @ the crimped wire connections., if so , i can be re-soldered.

Re: picture quiz of generator armatures

Posted: Mon Jun 07, 2021 6:42 pm
by Scott_Conger
What appear to be missing wires is a small clue

You really want to ask them to true your commutator and cut the insulation back then when you get it back, spray the daylights out of everything with Spray-On, Glyptal, or some other goop to nail down all of the old crumbling fish-paper before you reassemble.

I used to try to sell refurbished armatures, but couldn't get minimum wage for my time as everyone knew better and wouldn't spend the $. It is just as well as an original armature will open up in a mile or never. Due to very limited sales, I never got into a warrantee situation and the market solved that worry for me anyway. After that little Capitalistic venture, I only did complete restorations of generators. Given that a couple eBay guys sell Krylon rebuilds for less than the cost of a new armature, that flight of fancy left, too.

There is a reason that rebuilt armatures cost several hundred dollars and it is the same reason a correctly re-manufactured generator fetches $400.

Good luck with your project. If you haven't already, buy the MTFCA "Electrical" book before going any farther.

Re: picture quiz of generator armatures

Posted: Mon Jun 07, 2021 9:47 pm
by Jim
Well the one with both bearings is the one out of the car and the one they wouldn't even bother to test on inspection. The single bearing one is the good one. I'm tempted to go back to the shop myself just to get the education about what he saw that was so decisive that it was not worth testing.

I've ordered a new pinion gear, rivet, and the electrical book today so can hopefully have them before the weekend. We'll read up on it and tackle the re--assembly later this week. I have a couple of voltage regulators and I'm hoping one of them is good. I do have a good brush holder without any shorted third brush assembly and two sets of brushes with next to no wear.

Thanks for looking, I thought it would be interesting to see the responses and I wasn't disappointed. jim

Re: picture quiz of generator armatures

Posted: Mon Jun 07, 2021 10:02 pm
by John kuehn
Did the guy who checked them out actually tell you what exactly what was wrong with it? Evidently he didn’t seeing that you are tempted to go back and find out yourself. Looks like the one he said wasent good appears to have some missing segments but can’t tell for sure.

Re: picture quiz of generator armatures

Posted: Mon Jun 07, 2021 10:05 pm
by Scott_Conger
Jim

I would not use the one with the strawberried shaft. The gear will either wobble right away or will begin to wobble soon and will really wear your timing gear. That would be a sad byproduct of trying to save a nickle.

Better to advertise "Want to buy" a good armature from someone and get one with a good shaft. You will be $$ ahead when said and done. After getting a good one, at a minimum let a shop turn and undercut the commutator or you will be setting yourself up for failure either during the build or by all but assuring a short service life.

Would also advise setting up with a cutout and not a voltage regulator. It will at least allow you to see that the generator either is or isn't "genning" and you can't blow it up. If the generator works, then adjust it per instructions on the voltage regulator installation guide BEFORE installing the voltage regulator so as to not kill it. They are not exactly common these days and I know I would not knowingly risk sacrificing one to a newly assembled and untested generator.

Good luck

Re: picture quiz of generator armatures

Posted: Tue Jun 08, 2021 8:39 pm
by Jim
Wow the parts arrived from Langs in just over 24 hrs!

I've spent the evening trying to find the Fun Projects voltage regulator instructions on line and all of the links are not loading. Does anyone have a copy of the 'detailed' instructions for adding the regulator to a generator (came with the units when purchased).

Thanks in advance for the leads on this doc. jim

Re: picture quiz of generator armatures

Posted: Wed Jun 09, 2021 1:58 pm
by Jerry VanOoteghem
The one with two bearings looks fried to me. Maybe the guy just gave it the sniff test.

Hope you'll take Scott C's advice on the armature with the punched-up shaft.