3rd BRUSH Adjustment

[Professor Fate]

Feeling a little uncertain as to what to touch to adjust the 3rd brush.
I've read the ford service manual. Don't really feel good fooling with electrical ( as you may have read recently).
Does this look ok to you? It's set neutral with no charge or discharge. What's next??
The black discoloration on the green wire at lower left is paint.

[Moxie26]

Get yourself a piece of wood , just as wide as the copper segments and about a half inch thick by maybe a foot long... Wrap the end of the wood with some fine grit sandpaper. Start the engine and place the covered wood against the running armature the clean and brighten the copper contacts..... Then look at your ammeter and you may see that the generator is charging. I observe that the brush plate has been rebuilt, so even if you have to adjust the third brush for charging rate the movement will not crack a dried out insulator and ground out.

[speedytinc]

The mica does not appear to be cut down between the copper segments. Optical delusion?
The Setting of the near neutral was done with the 3rd brush up?
Rotating the 3rd brush toward the motor should increase the charge rate.
Be gentile tightening the 3rd brush nut. Just enough to hold. The carriage bolt head presses into the inner insulating fiber.
This is a very common area that grounds out the generator to appear dead from that broken insulator.

[Professor Fate]

It's a fresh rebuild.

[Moxie26]

Rebuild looks well done Dan. After the cleanup I suggested you should be pleased with the output of that generator.

[Professor Fate]

I just wiped it down gently with a little brake cleaner on a paper towel. Got a lot of black off the copper. Oily dirt film.
Maybe that was enuff. We'll see shortly.

[speedytinc]

It's a fresh rebuild.

Not to be pessimistic, but, that can mean very little.
Is the mica relieved as shown in your T1 manual?

I also rebuild generators.
3 of this next batch of 6 were recent rebuilds also.
Thats not an ab oration, just sayin.

[speedytinc]

Not throwing shade. I dont know your guy's work. Good you have a guy you trust for such work.

[Scott_Conger]

If it works, it will not work for long, honestly, or will be intermittent or slow to start charging, with the oxide showing on the faces

at a very minimum, do what Jablonski advised regarding the abrasive cleaning of the commutator. Use increasingly fine paper until it shines...not just matte colored copper, but SHINE (finish with 600/800 grit). This will give the longest life to both the brushes and pole faces as arcing will be at a minimum. Also, the brushes look new and not yet bedded to the commutator. After a lot of running, they will bed in and you will likely have to readjust your output. The poles should be undercut, but that's now water over the dam.

you want something that looks like this, but with a little better finished commutator (I learned after this one that as received from the armature winder, that they did not undercut well nor polish past 320 grit). The difference in audible noise and slight arcing on the test stand is surprisingly dramatic between this finish and a 600 grit finish. Lesson learned!!:

[speedytinc]

The brushes should have a mating radius to the armature. Out of the box, they are flat & make little contact.
A little drum sanding fixture does the job.

[Moxie26]

New generator brushes are made with a mating surface that has a curvature to closely match contact with the armature. ..

[speedytinc]

New generator brushes are made with a mating surface that has a curvature to closely match contact with the armature. ..

That interesting news. My old stock of brushes do not.
So I am destined to add that radius for the rest of my days.

[Art M]

I was told years ago to never use emery cloth or aluminum oxide paper to polish a commutater. Don't know if it is true and never tried it. I believe it was Larry Becker who told me this in the late 1950s. Any opinions on this matter.

Art Mirtes

[Moxie26]

Possibilities of metal abrasive particles shorting out the segments

[Professor Fate]

Polished with 800. Still no charge.

[Professor Fate]

Polished with 800. Still no charge.

[Moxie26]

Battery is negatively grounded? Momentary jump from battery terminal to generator terminal?

[Professor Fate]

Negative ground.

Jumped it from the battery lead side of the cutout to the other side. No sparking when jumping. And still no charge.

[Moxie26]

Do you have a 16 gauge yellow insulated wire from the harness connected to the battery side of your starter floor switch ?

[Professor Fate]

Do you have a 16 gauge yellow insulated wire from the harness connected to the battery side of your starter floor switch ?

I have the yellow battery wire from the harness on the power side of a 6v solenoid for my starter.

I have a battery cutoff switch that connects to the starter via solenoid and push button starter switch.
Floor switch is in the trash. Junk.

[Moxie26]

Is there battery power ( 6 volts ) at the terminal block on the firewall..... When the ignition key is turned to battery, do the coils buzz when the engine turns over ? Is the battery cut off switch in the on position ?

[Professor Fate]

Yes. 6v Battery power at terminal block.
"When the ignition key is turned to battery, do the coils buzz when the engine turns over ?" YES.

"Is the battery cut off switch in the on position ?" YES.

[Moxie26]

Is there six volts reading in the wire leading to the generator?
... If no six volt reading in that wire perhaps someone put a inline fuse , and now the fuse is blown ? .... Suggestions are good , but hands-on and visual are always better. Any word from Mr Patterson on your problem? .... My thought is to disconnect the battery cable and then to move the generator third brush upwards ( looking at the installed generator ) to increase generator output. Reconnect your battery and start car. Perhaps the brush is in a position of zero output?

[FundyTides]

Lots of good ideas here but I think you need to follow a logical step by step analysis of your issue to resolve this problem. If you are like me, and don't have an in-depth understanding of electrical theory, I found that consulting with Ron Patterson (The Coilman) led me to a quick and effective solution. In my case it involved replacement of the Brush Plate. Good luck!. Just as a side note, be careful that you don't have a modern semi-conductor cut out if you are trying to polarize the generator. I understand that this may damage/ruin the cut-out

[Professor Fate]

I have a Nu Rex from Snyder's.

Further testing reveals that I have current on the GEN side of the cut out. Tested by grounding test light to frame bolt and placing test light probe on GEN pole on cutout.
Light intensity was dimmer on GEN side than on BAT side of cutout.
So I'm possibly generating electricity but at a reduced level?

[Moxie26]

Is there six volts reading in the wire leading to the generator?
... If no six volt reading in that wire perhaps someone put a inline fuse , and now the fuse is blown ? .... Suggestions are good , but hands-on and visual are always better. Any word from Mr Patterson on your problem? .... My thought is to disconnect the battery cable and then to move the generator third brush upwards ( looking at the installed generator ) to increase generator output. Reconnect your battery and start car. Perhaps the brush is in a position of zero output?

[Moxie26]

I did add to my previous post about advancing the third brush for more charge readings

[Professor Fate]

Battery is negatively grounded? Momentary jump from battery terminal to generator terminal?

Yes.

[speedytinc]

Light dimmer @ gen terminal. Would be better to read voltage with an analog volt meter. There does appear to be gen output voltage, just too low. Move 3rd brush toward motor to increase output & recheck. When gen output exceeds battery voltage, you will get an increase on your ammeter.
Maybe you attach your test light to gen output, adjust 3rd brush & watch for a brighter test light.
If adjusting up your 3rd brush doesnt increase output enough it may be the whole brush ring is out also. Loosen the 4 brush holder screws & rotate for more output. Study the gen adjusting section in T1.

[John kuehn]

The armature segments need to be cleaned out it looks to me. After a good while of use the debris from wear and surface cleaning of the armature fill up the segments. Cleaning and polishing the armature is one thing to do but the next step is to cleaning up the segments.

You can do that with a fine hacksaw blade when the armature is on the bench and carefully do it. The generator repair book recommends to do this.

[Professor Fate]

Generator was set at 4 on the bench during rebuild. I'm going to leave it alone for now as I don't drive at night.
Thanks for the help!

[speedytinc]

Generator was set at 4 on the bench during rebuild. I'm going to leave it alone for now as I don't drive at night.
Thanks for the help!

Does your ammeter show 4 amp charge whall running med speed in your T? If so, everything is roses.
If not(dimmer output on test light), you are not putting out 4 amps @ 6v. Something fishy.
Is the test stand running the generator @ the correct speed as your T? No.

[Ron Patterson]

Here is an article I wrote about setting the Model T generator null point and how to correctly set the charging by setting the third brush adjustment.

[Professor Fate]

Thanks Ron.

I found the 2017 pdf article earlier this a.m. searching the forum archive.
I'm moving on to other small issues for now. I'll work on this probably next week.
Thank you!

[JTT3]

This is just my opinion others may disagree.
Ron P is an incredible resource to the hobby and to people willing to listen & learn. Are these two question below correct?

1- generator may be creating a charge but not clearly confirmed.
2- At this time you are going to leave everything as is

If those 2 statements are true then in my opinion you should ground the generator until you decide to resolve the problem to prevent further damage if any.

A question, can you take the generator back to the person that rebuilt it for you for further investigation?

When I called Ron to help me, he walked me through many steps to investigate the issue. The caveat was not to run the engine very long or at all, as to save the generator from further damage, until I was ready to follow the learnings unless the generator was grounded. Ron in effect saved me a bunch of money and helped me resolve the problem. That generator is still working like a charm 5-8 amps depending on rpm. I can’t thank Ron enough for his expertise and willingness to help at no cost for the advise.

[Luke]

I was told years ago to never use emery cloth or aluminum oxide paper to polish a commutater. Don't know if it is true and never tried it. I believe it was Larry Becker who told me this in the late 1950s. Any opinions on this matter.

Yes, I wouldn't recommend it, although while I couldn't possibly confirm there may be a slight case of 'do as I say, not what I do'

What have used in the past, and would recommend, is commutator [cleaning] stones (sometimes known as collector grindstones).

Even simply using these on the present commutator in a car could make quite a difference - when used in an operating (series wound) electric motor the increase in RPM following application of a 'commy stone' could be quite significant.

Not wanting to favour any supplier here, so a quick double-duck for 'commutator stones' will return plenty of places you can get them from.

Luke.