From: bruce C. Beattie (bruce@eecs.berkeley.edu)
Date: Mon Jan 03 2005 - 09:12:56 PST
Hi Aussierob,
That was an excellent post! I haven't seen that detailed a discussion
about comutator type devices in a long time, if ever. I used to repair
the DC lighting generators on cargo ships durring the Vietnam war.
Bruce MVPA 23824
aussierob wrote:
> Firstly I'm mainly a lurker here for a few years now, after some
> pissy purist/s did not like my style of message writing.
> ...and for that I make no apologies ...then or now!
>
> But I digress...
> Hello Mike It's Aussie Robb here ...aka
> Old Jeep Breath
> That Aussie bastard
> Robbo at the Sheep Dip Cafe' & Jeep Ewe'porium
> Upstate NY area near Syracuse
>
> In reply to your question are there any Quick Fixes?
> Yes and No ...because you'll need to perform
> more troubleshooting .
>
> Let's back up at little... from the UK, Noel, from across the pond hit on
> some things that were good and that I can add my 3 cents to !
> First is it a Generator or Dynamo... who cares ! however, it's
> definitely not an alternator !
> I may say that I have some experience in these matters and yet I will
> keep the post extremely simple.
> From the outset, if you are an Electrical Engineering major please
> hit the "effing" delete key.
> In the past, some of you (not all, but some) are just far too, well how
> should I put this...
> Nah... I won't go there right now! I'll be nice.
> (wait while I get off my soapbox)
>
> A SIMPLE EASY TEST:
> If I were you, I would try these first but in any order you desire.
> So, when faced with this elect problem here's my quick fix answers.
>
> Disconnect the fan belt .
>
> Remove the flat band/tin cover so you can view the commutator
>
> 1] That commutator may be shiny goldish color
> 2] it may be dark reddish shiny gold
> 3] it may be nearly black
> 4] It may have a big fat score mark around one section where the
> brushes have worn down so far ...that the copper leads (pigtails) are
> now running on the commutator instead of just the carbon brushes... and
> if that [4] is the case you will need to read further down below.
> It's not good and maybe can still be saved?
>
> Let's digress:
> You may need to grind a couple of wrenches or
> spanners, quite thin. You really need to hold the lower nut/s
> when undoing the genny connections as too often the whole stud would want
> to turn ...possibly breaking off the wires inside the unit)
>
> Disconnect the Regulator but leave any groundwire in place
>
> Run a decent 1/16th diam - approx 16 or 14g wire from the smaller field
> terminal
> on the Generynamo (Ha ha) to the big fat output post . (tighten carefully)
>
> Now don't be a Silly Ninny with this next action... just be a man
> with solid brass ones... OK you know what I mean !
> On the other hand, you may already be a tough, do it all fix it man,
> so the previous paragraph will not apply ! Ha.
>
> Grab a regular pair of lightweight cheapo car type Jumper cables.
> The cheaper the better ...in this case, if we lose a little juice
> through the cheapo connections ...it just wont matter.
>
> Run one of the cables from the battery's Grd/earth to the frame/bracket of
> the Dynamerator (HA ha)
> NB: I said the battery ground... but, take note this may be,
> Pos or Neg ...in your application ?
> So, let's assume it is Battery NEG for the ground in your case?
>
> The other cable, connect to the Batt POS+
> Now, you will try to run this baby as an electric motor.
> Yes an electric motor (This test will NOT work with an alternator)
> Note, if it is in good generating condition ...it will instantly spin up
> to high speed as an electric motor.!
> I've seen thousands of these and repaired & rewound dozens and dozens
> all types ...all sizes.
> (There are some types that have more than one smaller connection on the
> case.
> It may be that the extra smaller post is just a ground. It may be part of a
> fancier field coil design.
> This unit may have a third brush on the commutator ...which is not common.
> I will not get into these designs.
> I am really speaking here, of the type where you have a lighter field
> connection and the heavier Gen output connection
>
> NB: (note well)
> Now, you will TIGHTLY slam the jumper lead in your hand on to
> the big fat terminal.
> Don't try to clip it, just slam it in place and tightly hold it there.
>
> If you do this like a "silly ninny" or far too gently and deathly afraid
> or without the big brass balls that I afore mentioned ...then you will get a
> big silly flash and lots of spark/s
> You will not get a shock from the electricity, NOT, Not, not, not, get a
> shock at all.
> BTW, its not the sparks that are the problem it's how most people react to
> the
> sparks. Do not pee your pants at this first action as water and electricity
> don't mix
> well.
>
> Often, when you PULL BACK this allows for even more sparks, so jam it
> tightly onto
> the terminal and DONT Pull Back for several seconds!
>
> So repeating, Take good aim ...then, Jam tightly... the Pos+ cable onto the
> big fat post and
> leave it there for a few three to five seconds.
> This action applies your 6v or 12v across you armature and field coil.
>
> Instantly, a good Genny will throw itself into an electric motor, and a high
> speed
> wind up ...and, do not faint and fall to the ground
> If you are a sickly type, then have a helper hold your hand, ok !
>
> Several things will happen !
> it will turn over like a, well like a little boys piddle ?
> (a useless dribble in the wind)
> Or
> it will spin and start and stop and try to get going (like a giddy
> schoolgirl first crush)
> or
> It will not move at all ! (not a good sign)
> or
> It will take off like a bas-terd and spin like the devil and you will feel
> totally elated and happy and your breath will be taken aback !
> You can take the jumper cable off and stick it back on ...then off,
> then on, then off and you'll be grinning from ear to ear !
> When already spinning fast... you can push the connection on and
> off and you will only see a small spark
> "Well Done lads" ...will ring in the back of your head, which will be a
> throwback from your old school days science teacher/class
>
> However, if it does not spin as we all hope for... go to my next plan.
>
> to pull the unit - tear down and skim the commutator on a lathe then
> undercut
> the mica insulation between each copper segment approx 1/32" or slightly
> less - using a hacksaw blade.
> Grind the wavy part off the sides of blade so that the blade is no thicker
> than the gap between the copper segments. leaving the mica will eventually
> cause brush bounce. Because the mica and copper are of different hardness
> ...this can lead to a small amount of brush bounce causing very tiny
> sparking
> and that leads to heat
> and that leads to bigger sparks
> and that leads to melted solder where the armature wires
> join the commutator
> and that leads to failure, once again...
> and that'sjust where we started, right !
> (yes that was a run on sentence - it was meant to be !)
>
> If the commutator is just quite black it may be a dark copper oxide.
> Spin the genny by hand and stick a very fine grit paper in on the
> commutator.
> This will be perhaps, on the end of your little finger... because, there's
> just no room in there.
> I have actually done this with the power connected and the genny is spinning
> quite erratically slow. As the commutater suddenly becomes cleaner and a
> decent contact is made, that very same armature start to spin up to normal
> high speed revolutions.
> If this runs decently then you can rest assured you have a good genny
> However, what we haven't taken into account here is if there is an
> intermittent
> open circuit or even a short circuit in the windings.
> If there was that problem ...this perhaps would occur once the internal
> temp begins to rise.
>
> If the Gen. is good, it would be practically impossible on the internet to
> describe the many variables to adjust a voltage regulator.
>
> These days if I were you, my last move would be to take the reg and Gen
> to an old time auto electric shop for further testing as a pair.
> Best e'gards
> Robbo at the Sheep Dip Cafe' & Jeep Ewe'porium
> Syracuse area of NY
> Formally of Sydney Australia
> aussierob2@odyssey.net
>
> > Message-ID: <00ab01c4eff5$ae1bcce0$344786d9@b9u1z9>
> > From: "noel shelley" <noel@shelley1722.freeserve.co.uk>
>
> > Hi Mike and all the Gentlemen of the list !
> >
> PLEASE
> > when referring to the device that makes electricity in all our vehicles
> can
> > we adhere to the normally accepted terminology !
> > A DYNAMO is a device that produces DC electricity , by virtue of the
> > commutator ! {used till late 60`s }
> > An ALTERNATOR is a device that produces 3phase AC, rectified to DC by the
> > rectifier pack {6 diodes for the 3phase + 3for the warning light }[used
> > after the 60`s]
> > Before you collectively throw me to the dogs , YES I know the above is a
> > VERY simplistic view but will suffice for now !
> >
> > CCKW--- sounds old-- ish , probably a dynamo , right ? If so then check
> the
> > brushes , long enough , free in their holders and clean ! Commutator clean
> ,
> > not spun solder out , armature not dragging on stator due to worn bearings
> !
> > NO burnt out wires !
> >
> > How can I eliminate anything between the two !
> >
> > A simple continuity test , a bulb and a bit of wire & battery ! Disconnect
> > both ends and see if the bulb lights up when connected !
> >
> > The voltage control box is a wonderful collection of coils & contacts ,
> only
> > play with this IF you have the data , the test gear and know how to use it
> !
> > You can clean the contacts , but use only a contact file or GLASS
> > PAPER ---- NOTHING ELSE ! be VERY careful NOT to open the contacts more
> than
> > is essential to clean !
> >
> > Alternators also have brushes that wear out ! They are usually regulated
> > electronically and have no serviceable parts , just rebuild !
> > SOME alternators will not work if the warning light bulb fails !
> >
> > Just in passing , a vehicle with a Completely flat battery and dynamo will
> > if towed power up and start {manual box }, but if fitted with an
> alternator
> > will NOT, due to the alternator needing power to generate !
> >
> > More nonsense from Noel Happy New Year!
> >
> >
> > ------------------------------
> >
> > ----- Original Message -----
> > From: "42Ford GPW" <ilovejeeps@hotmail.com>
> >
> > >
> > > Maybe the voltage regulator ?? How can I eliminate anything between the
> > > two ?
> > >
> > > Any advice appreciated!
> > >
> > > Thanks
> > >
> > >
> > >
> > > Mike Curtis
> > > 1942 GPW(2) 1943 WC-52
> > > 1942 MB 1943 WC-56
> > > 1944 MB 1951 M37
> > > 1951 M38 1963 M37-B1
> > > 1955 M38-A1 1968 M35-A2
> > > 1972 M151-A2
> > > 1942 OPEN CAB LWB CCKW
> > > FORD GPW SPARE PARTS/BOXES/TAGS, ETC.
> > >
> > >
> > > what steps do I have to take in order to get it back to a normal -
> ground
> > > system ??
> > >
> > > thanks in advance!
> > >
> > >
> > >
> > > Mike Curtis
> > > 1942 GPW(2) 1943 WC-52
> > > 1942 MB 1943 WC-56
> > > 1944 MB 1951 M37
> > > 1951 M38 1963 M37-B1
> > > 1955 M38-A1 1968 M35-A2
> > > 1972 M151-A2
> > > 1942 OPEN CAB LWB CCKW
> > > FORD GPW SPARE PARTS/BOXES/TAGS, ETC.
> > >
> > From: "noel shelley" <noel@shelley1722.freeserve.co.uk>
> > Subject: Re: [MV] *** SPAM *** Re: [MV] CCKW generator not
> > working....any quick fix tricks ?
> > Date: Sat, 1 Jan 2005 21:18:44 -0000
> >
> > a "DYNAMO" is "GENERATOR" in American and Canadian parlance
> >
> > OK ,so what do you call an alternator , since both gererate electricity ?
> >
> > Noel
> >
> >
> > ------------------------------
> >
> > End of Military Vehicles Mailing List Digest #1920
> > **************************************************
> >
>
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