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Flathead generator conversion

Discussion in 'The Hokey Ass Message Board' started by tommy, Jun 11, 2005.

  1. tommy
    Joined: Mar 3, 2001
    Posts: 14,736

    tommy
    Member

    [​IMG]

    Your basic 8BA 6v generator. It's white because the stainless cover still has the scratch protector on it. The 2 bolts at 6 oclock and 12 hold it together. Remove the 2 bolts and gently pry the end plate off of the generator body. Careful the end plate is aluminum and after 50 years it can be stuck pretty good. You can snap off a piece if you get too rough with it.

    [​IMG]

    Unlike a pocket watch, no springs and gears will fly across the room when you open it up. No diodes or transistors, just brushes that any idiot with a screwdriver and a wrench can change.

    [​IMG]

    This is the generator body with the field windings inside. This is all you need from a 56-64 Ford 12V generator to convert a 6V unit to 12V unit.

    [​IMG]

    The copper segmented section of the armature is called the commutator. That is the part that the brushes ride on. You can see some arcing in there after dark and the carbon brushes will make it look dirty.

    [​IMG]

    A few seconds with some Scotch Brite or 400 sand paper will clean it up nicely.
     
  2. tommy
    Joined: Mar 3, 2001
    Posts: 14,736

    tommy
    Member

    [​IMG]

    Here it is as it goes back together.

    [​IMG]

    These threaded holes in the front bearing plate need to be positioned at 12 and 6 oclock for the bolts to screw into. The body needs to be aligned so that the bolts can pass through it between the field windings. When you look at it, it will be all too obvious.

    [​IMG]

    This slightly out of focus shot shows that the brushes need to be pried back into their housings with a screw driver so that they will clear the commutator as you slip the unit together.

    [​IMG]

    You will need a 12V Ford voltage regulator wired as this crude diagram shows. Tell the pimply parts counter kid it's for a 1964 Ford Failane, 6 cyl, no A/C, P/S or cruise control.

    After it's installed and wired, MOMENTARILY touch a jumper wire between the armature and the battery terminals on the voltage regulator to get a spark. This is the procedure for polarizing an externally grounded generator. Other types are done differently.

    I know this is very basic stuff to for many of us but it's slightly more involved than bolting on a chromed one wire alternator:D and there are lots of guys that have built some righteous cars that's never messed with a generator.
     
  3. tommy
    Joined: Mar 3, 2001
    Posts: 14,736

    tommy
    Member

    Since I'm the only one to reply to this post, I have no idea how it got the 5 stars. itwernt me, but I'll give it one more pass through.
     
  4. hotrodA
    Joined: Sep 12, 2002
    Posts: 2,063

    hotrodA
    ALLIANCE MEMBER

    Good information. Thanks for posting it with the pics.
     
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  5. noboD
    Joined: Jan 29, 2004
    Posts: 5,542

    noboD
    Member

    Thanks Tommy for the info. I know I've read in a service manual not to use emory cloth on a armature, only sand paper. any idea why?
     
  6. Jaypee
    Joined: Feb 3, 2004
    Posts: 595

    Jaypee
    Member
    from Finland

    Good info. Thanks Tommy.

    Jaypee
     
  7. tommy
    Joined: Mar 3, 2001
    Posts: 14,736

    tommy
    Member

    I believe it's because emory is a conductor. If enough gets built up between the segments it can short the two segments together. Each line in the commutator is an insulator between segments. I use Scotch brite which wasn't around when thay wrote service books on generators.
     
  8. noboD
    Joined: Jan 29, 2004
    Posts: 5,542

    noboD
    Member

    Thanks, no one else has even guessed at an answer. Sounds like a good one. One other dumb generator question, when using a growler does a good armature growl or no?
     
  9. Flathead Youngin'
    Joined: Jan 10, 2005
    Posts: 3,531

    Flathead Youngin'
    Member


    Thanks again, Tommy. I was really debating on how I could run a Flatty generator on 12v without spending a bunch of cash! I really didn't want to hang a Chebby alt. on my old hot rod...
     
  10. tommy
    Joined: Mar 3, 2001
    Posts: 14,736

    tommy
    Member

    Well I guessed wrong. I was checking my old motors manual about how a growler works...It had a picture of a mechanic checking the armature with one but didn't go on to explain the process. Since you are checking for hidden shorts, my guess would be that a short would cause it to growl but I'm 0 for 1 on guesses today.

    There in the book it said never to use emory cloth because bits of emory can get embedded in the segments promoting rapid brush wear. Emory must be some pretty hard stuff.

    Well I'm either 0 for 2 or batting .500:D

    It was interesting how the book tells you not to just discard a shorted armature but gave several possible cures to repair it. There is a lot of interesting reading in one of those old blue Motors Manuals. They were written for repair mechanics not parts changers...back when labor was cheap.
     
  11. Mr 42
    Joined: Mar 27, 2003
    Posts: 1,187

    Mr 42
    ALLIANCE MEMBER
    from Sweden

    This one is for the Tech Archive.

    Ive been running a conversion like this for two years and it works Great(put out up to 35 amps).

    A small tip you if you push the brushes outward you can hang up the spring against the brush. And after you have mounted the plate, you can give the brush a push with a screwdriver, thru the generator body slot's.
    The makes assembly a breeze...
     
  12. pigpen
    Joined: Aug 30, 2004
    Posts: 1,624

    pigpen
    Member
    from TX USA

    Excellent tech post! :)

    pigpen
     
  13. Psychobilly Boi
    Joined: Feb 5, 2003
    Posts: 2,084

    Psychobilly Boi
    Member

    hey crew,

    excellent post!

    danny
     
  14. burger
    Joined: Sep 19, 2002
    Posts: 2,319

    burger
    Member
    from burbs

    Tommy,

    Thanks for posting this! It may be old hat to the old timers, but to us young guys who are used to just replacing the alternator at the first sign of trouble it's nice to see how to actually repair something.


    Ed
     
  15. NOBILLETA
    Joined: Jan 26, 2005
    Posts: 152

    NOBILLETA
    Member

    Just as a minor addition, If memory serves me correctly (and these days thats not a given) with a growler the armature is considered good or bad by holding a hacksaw blade slightly above it in several positions, if the blade is magnetically drawn to it, it's good . thats the way I remember it anyway.
     
  16. Flathead Youngin'
    Joined: Jan 10, 2005
    Posts: 3,531

    Flathead Youngin'
    Member

    Hey, Tommy, great thread. I'm getting ready to hook up my generator in a week or so.

    I bought a generator from a good ole fella that said he just converted it.....it looks real good (new paint makes anything look good, huh?). Anyway, mine has two wires coming out of it. They go directly into the top of the generator (where the little metal cap belongs) and does not attacth to the posts- like supposed to. I removed the metal dust cover and it looked to have 3 brushes but only two wires coming out. How can I tell which wire is which?

    I assume this 64 regulator will work on this one too...
     
  17. alchemy
    Joined: Sep 27, 2002
    Posts: 7,714

    alchemy
    ALLIANCE MEMBER

    If your generator has three brushes, it's a different animal than most guys use. I think they stopped using those in '38. I also believe the later 12 volt housing and fields are not gonna be compatible with that '38 armature and rear plate.

    Tommy used an 8BA generator, but a '40 - '48 can also be used the same way in a 12 volt conversion. The later 12 volt parts go onto both of these the same.
     
  18. Flathead Youngin'
    Joined: Jan 10, 2005
    Posts: 3,531

    Flathead Youngin'
    Member

    I noticed this when I was telling grandpa on the phone. So, wonder how in the world this fella converted this 3 brush genny to 12v? I assume he just didn't hook up one of the brushes but wonder what commutator he used. I would have asked him, but I ASSUMED that he just what Tommy is showing.

    So, you think the later 12v commutators will work in 8ba style (Tommy showed) AND the 2 post 38-48 (or so) BUT not the earlier 3 post......

    Since I still have two wires coming out of mine, can I use the same regulator that Tommy is showing?
     
  19. tommy
    Joined: Mar 3, 2001
    Posts: 14,736

    tommy
    Member

    Yeah, that sounds like a 36 6V gen. I had one on a 36 P/U. It used a "cut out" (a small round sheetmetal box on top of the generator) and didn't have a V/reg. I always parked it on a hill in case the cut out points stuck. When they stick the battery drains down. They have modern fixes for that but they are 6V anyway.

    I wasn't sure what year bodies were the same diameter as the later 12V bodies. I'm sure alchemy is right. Sounds like you need a newer 6V generator to convert. Now if you need the fan mount generator pulley ...then you have another problem. If the 40s era generator will work in your application, then they should be easier to find.
     
  20. tommy
    Joined: Mar 3, 2001
    Posts: 14,736

    tommy
    Member

    You change the body with the field windings. The armature with it's commutator is still the 6V armature. The 6V 2 brush end plate stays also.
     
  21. oil*can*harry
    Joined: Jan 26, 2005
    Posts: 431

    oil*can*harry
    BANNED

    After cleaning the armature with garnet paper, not emery, you should clean the gaps between segments also.
     
  22. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 19,519

    Bruce Lancaster
    Member

    I'm very close to being able to post solutions to the 2-brush with fan solution, I think. The parts needed are much more common than I thought!
    I believe there are commercial conversions out there to regulate current on 3-brushers and to convert them to low amp 12's. I also think the wires coming off the fields and brushes could be hooked up in such a way they could be regulated by a normal Ford reg with some time spent staring at the diagrams and some high intensity thinking.
     
  23. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 19,519

    Bruce Lancaster
    Member

    Oh, yeah, I've heard two different folkloric reasons for not using emery on gens: First and most common is that the grains are conductive, the alternate is that the stuff leaves a residue. No idea myself, but I avoid using it on anything electric.
    Old practice on cutting commutators was to cut away a bit of the insulation between segments after turning, leaving a groove, something that can be done with a special cutter that comes with armature lathes or with a hacksaw blade...I believe more modern publications say this is not necessary.
     
  24. alchemy
    Joined: Sep 27, 2002
    Posts: 7,714

    alchemy
    ALLIANCE MEMBER

    Boy would this be good to see! Two years ago I went through every parts book and catalog, as well as numerous 12v conversion articles trying to devise a way to use a pulley with the fan boss on it. I ended up maching a '36ish pulley and making spacers. Not the best solution. Hopefully you have something more Fordish and less Goldbergish.
     
  25. louvers
    Joined: Jun 3, 2006
    Posts: 68

    louvers
    Member
    from alameda,ca

    [​IMG]

    Here it is as it goes back together.



    These threaded holes in the front bearing plate need to be positioned at 12 and 6 oclock for the bolts to screw into. The body needs to be aligned so that the bolts can pass through it between the field windings. When you look at it, it will be all too obvious.

    [​IMG]

    This slightly out of focus shot shows that the brushes need to be pried back into their housings with a screw driver so that they will clear the commutator as you slip the unit together.

    [​IMG]

    You will need a 12V Ford voltage regulator wired as this crude diagram shows. Tell the pimply parts counter kid it's for a 1964 Ford Failane, 6 cyl, no A/C, P/S or cruise control.

    After it's installed and wired, MOMENTARILY touch a jumper wire between the armature and the battery terminals on the voltage regulator to get a spark. This is the procedure for polarizing an externally grounded generator. Other types are done differently.

    I know this is very basic stuff to for many of us but it's slightly more involved than bolting on a chromed one wire alternator:D and there are lots of guys that have built some righteous cars that's never messed with a generator.[/quote]
     
  26. Flathead Youngin'
    Joined: Jan 10, 2005
    Posts: 3,531

    Flathead Youngin'
    Member

    I was wrong. I have NO posts on my generator. However, when I had the dust cover off, I would swear there were 3 brushes in there.

    There are only TWO wires coming out of my generator. This ole fella was set up at a swap meet and was pretty knowledeable on flatty stuff. I bought almost everthing he had. He had taken time to clean everything and paint it.....still had GREAT buys on stuff .....the more I bought, the better the prices were. I think he was just glad a young (good looking) young man was into flatty stuff. Anyway, my point is, I think he was sincere when he said he converted it to 12v- I have no reason to doubt him. Wonder how he did this?

    I'm getting ready for a trip to King's Island right now- leaving in the morning. While ALL the other good little HAMBr's are going to be looking at 6k+ hot rods at the Columbus Good Guys, I'll be watching a Nickleodeon parade tomorrow (I hope they don't hate me, I know jealously runs high:rolleyes: ).

    I could tear this thing down, but I still wouldn't know anything......

    So, can I run the 64 Ford regulator with this.....ya think?

    I'll have you all in my thoughts when I'm watching Sponge Bob go passed and you all have to stare at 500 red 32 roadsters....neener, neener, neener.....:cool:

     

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  27. tommy
    Joined: Mar 3, 2001
    Posts: 14,736

    tommy
    Member

    That round "dust cover" is actually a 6V generator cut out. Yours has been modified. Originally there were points inside that housing that was supposed to disconnect the generator from the battery when the gen was not charging. (engine shut off) They were prone to stick letting the battery drain down through the generator after you shut the engine off. I know some people use diodes out of modern alternators to replace the points. That allows the juice to flow one way into the battery only. I have no idea how yours is modified. You need to trace the wires to see where they go.

    Sorry I have no clue how to modify a 3 bush generator for 12V and a 12V reg. My guess is that it is not easy because there are a lot of guys looking for that special fan mount pulley to use on their 2 brush 12V converted generator. Hopefully Bruce will come up with the answer.
     
  28. Flatdog
    Joined: Jan 31, 2003
    Posts: 1,287

    Flatdog
    Member Emeritus

    Great info ,going in to my save stuff.
     
  29. Automotive Stud
    Joined: Sep 26, 2004
    Posts: 3,667

    Automotive Stud
    Member

    New bearings are still available locally also. I'll try to dig up some numbers...
     
  30. xadamx
    Joined: Apr 18, 2003
    Posts: 1,155

    xadamx
    Member

    Maybe a dumb question, but do you have to polarize? I did this 12v conversion on my 8ba and never polarized the generator. What are the downfalls of not polarizing? Benefits? My car seems to run fine but the battery seems to lose the charge after a week or so and needs to be charged again. Also, can it be polarized now, after a few months of use? Thanks a lot, and great info!

    Adam
     

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