Third Brush Adjustment

[spinelll]

Referring to the attachment. Is that the third brush?
Trying to increase the output.
Attempted to move the brush towards me. That is, towards the driver's side.
But it doesn't budge. Is there something to loosen?

Thanks
Leo

[nkaminar]

Here is a video that may help: https://www.youtube.com/watch?v=yYlpy75GdA4
There is something funny about your generator. The bushes should all ride in the center of the commutator. Your brush is off to one side.

Plus, here is a thread from 2014 that may be helpful. https://www.fordbarn.com/forum/showt...t=adjust+brush

[Bob C]

That looks like the ground brush. X2 the brush is not all the way on the commutator.

[rotorwrench]

That appears to be a straight down photo shot so the brush that is evident is for the ground on the right side of the gen and is fixed. The brush that is approximately 180 degrees from it on the left and slightly lower side is the fixed power output brush. The 3rd brush or field current control brush is just above the power brush and is the only movable one. It is mounted on a ring that has a good bit of friction applied to it to keep the brush from moving on its own.

The generator does seem to have a problem with centering of that ground brush and likely has a problem with the others as well, That generator may either have the wrong armature in it or the generator is in a state of disassembly that allows it to move too far forward. It may have a brush location problem but the brushes are generally right in the middle of the windows there and all three are even with each other in distance from the backing plate.

[Badpuppy]

I vote for wrong armature - short nose in a long nose. Third brush is under the gnarl of whatever below the other slot. Ground brush he's trying to move has stranded wire to ground.

[David R.]

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Pull it out and rebuild

[spinelll]

Ok, so my arrow was not pointed to the 3rd brush. It's the one below it, surrounded by wires.And I did notice that only about 3/4 of the brushes are in contact with the commutator.


Thanks for the responses.



What is the recommended charging rate at a mid to high rev?

[Patrick L.]

I think the generator needs to come apart and looked at.

Charge rate depends on what type cut-out is used and how the vehicle is run. A standard cut-out I like 3-4 amps for normal daylight light operation with occasional night use. 8-10 amps if used a lot at night. I don't like to run more than 10 amps with these generators.

[nkaminar]

Ford recommended that the mechanics at the dealers measure the electrolyte specific gravity when the car came in for service and change the charge rate accordingly. Each driver had different requirements.

I recommend that, in addition to the normal ammeter, you install a volt meter. It is a better method to keep track of the battery. For a 6 volt battery, the voltage should be between 7 and 7.3 volts after the car has been driven for at least 5 miles.

[rotorwrench]

System voltage depends on the condition of the battery so that may not always be reliable. Some folks set it high and run the lights all the time. Those that don't drive at night much and don't want to run lights all the time can set it lower. Even the alternators have a tendency to overcharge the battery.

[spinelll]

Whoa!
I just noticed why the brushes are not in complete contact with the commutator.
Pictures are worth 1,000 words. That armature shaft has a load of play.
When I push it in manually, the brushes are in full contact.

I image that once it's spinning, centrifugal force is pulling it out.

[katy]

Originally Posted by Patrick L.

I think the generator needs to come apart and looked at.

Ditto

[nkaminar]

You may be missing a thrust washer or two.

[spinelll]

Originally Posted by nkaminar

You may be missing a thrust washer or two.

When you say thrust washer, which part(s) are you referring to?

[nkaminar]

Look at all the parts from item 17 through 23, especially items 20 (two parts). Also the hardware that holds the front bearing assembly all together, items 13, 15, and 24.

[spinelll]

Ok. Thanks.

[Bob C]

Here is a picture posted a few years ago by Tom.

[Bill Cilker]

The picture that Bob C. posted is for the generator style that was produced before your style. Your generator has a bushing on the rear plate, not a roller bearing.

[spinelll]

A club member lent me a generator that had no shaft play, to which I attached my original cutout. Hooked everything up and it "seemed" ok.


I wasn't sure how good my ammeter was so later on, I decided to swapped it with a new one I had laying around. What I failed to notice was that the old ammeter was a 30-30 and the new one is a 20-20.



Whoa, the new ammeter jumps around like a road lizard on hot macadam. At either slow or high idle, it wobbles like mad. At slow idle with the lights on I'm wiggling around -10, at high idle lights off +10 but it moves so much, it's hard to get an accurate reading.



Where have I gone wrong? I know, the list is long.

Do I re-install the old ammeter?

How do you check the current from the cutout with a multi-meter?


Thanks
Leo

[rotorwrench]

Ammeters have to read the flow in the line which means they have to be connected in the line. The best place to do that is where the OEM ammeter location is since it separates the battery side from the charge side. The original ammeters were cheap little trinkets back in the day but they are worlds better in function and quality from the crap they sell for reproductions in the modern era. A hall effect ammeter with a clamp over the line would be better than trying to connect a multi-meter in the line. Digital units can give flaky indications. An ammeter with a d'arsonval needle movement is better.

[nkaminar]

In the service bulletins, Ford recommended that the mechanics check the amps the generator was putting out with a shop ammeter that was more accurate than the one in the car.

If the ammeter is jumping around then there is a loose connection somewhere. Or the generator has a fault. Use your multimeter to check for resistance at connections while you are wiggling the wires. Do this with the ignition on but the engine stopped and the points open or a piece of paper put between the points.

Take you original generator to an electrical shop where there are people working that are at least 60 years old. Or take it apart yourself and fix the slop in the armature.

[Badpuppy]

20-20 is the appropriate ammeter; it measures only battery current. -10A is about right for lighting load, +10 is too high to charge battery for very long. You should expect a certain amount of jitter from the ignition coil. The battery is an enormous capacitor and should act as a noise filter. Erratic behavior may be due to a weak connection toward the battery.

[rotorwrench]

While a battery does have a capacity to store electrical energy by the means of chemical reaction, it is not a capacitor. A battery has an electrolyte connection between the positive and negative plates where a capacitor has an insulator between the plates so there is only an electric field between the two when charged. The field can only build to its rated capacity and when disconnected it slowly bleeds off into the circuit.

When a capacitor used as a radiated radio frequency interference suppressor, it will absorb the radiated RFI then bleed it off through the ground plane. This stuff is usually only needed on older vehicles that may still have wire core high tension leads and mechanical vibrator type voltage regulators & instruments. They even used to put brushes inside the front spindle hub cap to ground out the friction made by the brake drums.

[nkaminar]

Although the battery stores energy by chemical action, the plates are close together and will act like a capacitor. Here is the answer to the question of whether the battery is (will act like) a capacitor:




Barry Hunter, former Automotive and industrial battery and charger tech
Answered 2 years ago · Author has 550 answers and 980.3K answer views

Yes, it is. The output of a car’s alternator is unfiltered DC. The battery acts as a filter capacitor to smooth out the waveform. Once the car is running you can disconnect the battery and it will continue running as long as you keep the RPM up. You might destroy the electronics though.

DC power supplies require large capacitors to smooth out the rectifiers waveform. Battery chargers and car alternators do not require filter capacitors because the battery itself acts as a filter capacitor.

I serviced chargers from 6VDC to 80VDC charging batteries from 1 lb to 5000 lbs.
None of them had filter capacitors and the output was very clean with very little AC ripple. A 1000 lb battery acts as a damn good filter capacitor.




That being said, a small capacitor near the source of the electrical noise will filter out high frequency. You used to see these capacitors on the electrical connection to radios and other devices that were sensitive to high frequency electrical noise. The frequency that a capacitor will filter depends on its capacitance. The smaller ones will filter out high frequency while the larger ones like the battery will filter out lower frequencies.

[rotorwrench]

A lot depends on why a repairman needs to install filters. Back in the day it was for good radio reception on the common AM receivers in automobiles,

The output of an alternator is alternating current that is rectfied to DC through a diode bridge. If all is functioning as designed there is very little AC frequency leakage. RFI is not quite the same thing. It is radiated and not something that circulates just through the body, wiring, and frame of a vehicle. Capacitors only work if they are attached at the source of the RFI.

An alternator will supply energy to the electrical system buss even if the battery is cut out of the system due to the amount of output it can sustain. It loses some functional stability though so it's not recommended on aircraft to turn the battery off and leave the alternator running. If there are any spikes, the battery is not there to absorb them.

We used filter capacitors in aviation due to the requirement of radio communication through VHF and FM transceivers plus navigation receivers. The magnetos have shielded high tension leads so they aren't much of a problem but alternators and electric motors can be. RFI can be a problem on some aircraft. I've had several helicopters that had less than perfect ground planes due to corrosion and capacitors plus extra bonding jumpers were required to reduce the RFI to the point that the radio and navigation equipment would function properly. Antennas and ground planes also need to be maintained to keep things working properly.

Capacitors are primarily used in AC circuit to help tune frequencies. The battery can not function in an AC circuit. It is strictly a DC component. It holds a charge in both current and voltage. A capacitor only holds a charge in an electric field. It acts more like an accumulator in an electric circuit. The only reason it works in an ignition system is due to the pulsating half wave current that is generated in the coil by the points opening and closing. The vibrator in an old AM radio set does the same thing.

[Badpuppy]

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All I was trying to say was that a battery has an equivalent capacitance of a couple of farads, which makes a lovely DC filter.

Didn't mean to incite a an animated discussion of different viewpoints.