Hello, I am Jens from Germany currently restoring a TT 1925 which I imported from Tenessee a few years ago. I`m following you guys for quite some time and it has been a great help! Unfortunately my Gen is starting to get very much on my nervs. Basically, I cannot get any positive charging on the ammeter. I looked through quite a few threads but I cannot locate the error. Taking in account the questions asked in the threads here's the description:
Engine is standard late 1924, no fancy things like distributors or 12V etc.
Gen is a rebuilt type with funprojects cut-off.
Engine runs well on Mag. On Gen idling is good but engine does not really want to rev up
On Bat side of cut-off I have the Bat voltage 6,3V. No resistance all the way back to Bat. 0 Ohm
Gen casing has good ground
The highest reading I had on Gen side of cut-off is 5 - 6V. No reaction on 3rd brush adjustment. I have a rather simple digital device to measure (maybe $20 type)
The ammeter reading usually stays at zero being a bit nervous, but not much. Last start I could see flicking from -20 to +20, >very nervous. At the end voltage was 0,3V on Gen side.
Ammeter shows discharge 4 amps with one head light and engine not running, so it seems ok.
Acc. to some thread ammeter flicking around is an indication for brush problem or severe damage, so I opened the Gen:
General appearance looks good to me, see pictures.
Rotor: resistance between commutators 0,4 Ohm all the way around. No grounding to rotor shaft.
resistance 3rd brush to ground 4 Ohm
resistance brush to connection of cut off 0,5 Ohm
resistance 3rd brush to the other brush (all the way through the coils) 4 Ohm.
This brush to ground 0,4 Ohm
The other brush no ground
The only thing I cannot check if the cut-out is of right Voltage because I cannot read the label anymore. see picture.
I hope you guys can help me out. If necessary I can make a call for clarification. Photos are uploaded as attachments. Jens
some additional information
Brushes move freely
Rotor has 5mm axial play and you can see it moving back and forth through the windows, but brushes stay fully on commutators
Since the rebuild, did the generator ever worked properly?
First of all you need to get rid of the axial play on the rotor.
Did you set some current over the coils and check the magnetism?? You should find N-S-N-S.
Can you make the generator run as a motor on a battery, off the engine? Does it run with the 3rd lift up?
Where do you live in Germany?? I am living in Belgium on the way to Brussels on about 70km from Aachen. You can maybe come over to try to make it work??
Andre, according to Google Maps, Jens is close to Leipzig, about five hours from you. Beetje ver om even langs te wippen...
Jenz , as you know you can not use an digital volt meter for a Model T.You need an Analoog.
If you have holiday in Holland you can visit me.
greetings from Holland
How is your battery? Is it fully charged? What is the hydrometer reading? The Fun Projects regulator will hold the charge rate down if the battery is OK. If you are concerned about the generator output, you could temporarily replace the regulator with a regular cutout. Then the generator will continue to charge the battery at a higher voltage and show charge on the ammeter. If the battery is OK there should not be any charging.
yep, I'm close to Leipzig Germany. Here are the responses to the questions:
I have never seen the ammeter charging! The other effect: The less Voltage the gen is giving the more is engine's reluctancy to rev up. This happens only when on Bat!
The battery is from 2009 or so. I have tried the system with bat full and almost empty. Both do not make a difference. I never hydrometered the bat. I can do this on Monday.
Next week I will get an analog meter. But the resistance readings should be ok.
Next thing I had in mind was getting rid of the play. At work we can make the gen running as a motor and I think we did already. But definetaly I was not trying to lift up the 3rd brush.
Belgium is not far because within the next 2/3 weeks I will be on a business trip to Dortmund.
Andre: If it is alright for you, I might come over with my things.
I'll come back with more news on Monday.
thanks, I haven't expected that great help here in Europe. Jens
I send you an Email. just reply.
Just making sure I run the gen correctly as motor.
Which pole of bat is to be connected to what on the gen.
+ on the terminal and - on the generator body.
Lift up the 3rd brush.
Loose the 4 small screws on the back of the generator, how hold the brush plate, and turn the brush plate left or right till the generator stops running and you can't make it run left or right even if you try to make it run by hand. This is the neutral point of the brush plate, tie up the 4 screws. Set the 3rd brush holder all the way down, away from the terminal. Set back the 3rd brush. The generator should run again as a motor. Put on cutout/regulator and make it run on a test stand or your engine. Now you can set the current by moving the 3rd brush clock wise till you have 2 to 3 amp.
Jens you said "The less Voltage the gen is giving the more is engine's reluctancy to rev up. This happens only when on Bat!" This sounds odd, When you switch from Battery to Magneto, you are just moving the ignition coils over from the battery to the magneto. The generator is still connected to the battery and would still be charging (or Not) the battery. Make sure your ammeter is wired correctly, it needs to be between the generator and battery and not between the generator and the load. If the ammeter is in the latter, it will show discharge but not charge.
Also if you have a spare ammeter connect it in series with the output of the generator. That will show if the generator is putting out, so to speak.
Hope this helps.
Did you make the control only with the inboard ammeter ? It is 88 years old don't trust it !
Check with some modern ammeter and voltmeter.
If the voltage readings given were correct then 5 to 6 volts at the generator post with 6.3 Volts at the battery side of the cutout says that the generator is not putting out anything at all. He also stated that moving the third brush had no effect on this either. That also confirms that the generator is the issue. This setup is NOT equipped with our Voltage Regulator or at least none that I could see in the pictures. What I DO see is a model T cutout mounted on the generator and it would appear to be OK based upon the voltage readings given for the setup. I agree with those who said you should disconnect the generator from everything and then connect it up to see if can be made to "motor" since it seems to have the generating capability of a smooth rock at this point. Focus your efforts to the generator.
"... it seems to have the generating capability of a smooth rock at this point."
Jens ; The best way to test a generator is on a bench tester, then you know what you are doing. It is not difficult to make one and you can have a lot of pleasure of it.
I agree totally with Toon that the best way to test a generator is via a simple motor driven setup that allows you to monitor the generator only to make certain it is in good working order including full range of proper adjustment of the third brush without any "funny stuff" happening as you move the third brush. The one pictured looks like a very good unit since it has provision for solid mounting and solid drive motor hook up. I would simply like to offer that for this test setup do not use a Voltage Regulator. It will be attempting to regulate the output and even perhaps to shut down the generator if it senses there is no battery connected. It will only confuse the testing of the generator and if the generator has some serious internal issues you can damage the regulator. Also do not use a mechanical cutout since those can be intermittent and again confuse the test. A known good diode cutout dedicated to the tester is the best solution and it can be quickly tested with an ohm meter should you have any doubt that the cutout has been damaged which will be a rare occurrence if you are at all careful.
It is not wise nor accurate to attempt to setup a generator final third brush setting while on a tester. That adjustment must be performed on the final host car with its electrical system connected.
To ad to my previous post : Behind the volt and amp. meter there are three bulbs and a switch. The bulbs are about the same as the two front and back bulbs in the lamps on a model t. so I can see what the gen. is doing when the lamps are on. Normally I set the third brush so that the output is zero or a little less when the lamps are on.
I have to say that while I would agree with testing the generator with your 3 lamp load, leaving the generator at that setting might be way too high for normal daytime driving.
thanks for all this help you are giving.
I have done part of my homework and that's the feedback:
The ammeter is almost new (replacement part probably from MAC's). I checked the reading with a headlight, see my opener of the thread. I can confirm having 6,3V on the bat side of the gen for both key settings Bat and Mag. I checked the wiring a couple of times and it is correct.
Instead of lifting of the 3rd brush, I pull the 30 Amp fuse next to it. This makes life easier and it should not make a difference, correct?
This way I found the neutral point of the gen and tied the scews on the back. But I do not understand the next step to do with the 3rd brush. I'm not a literature man but more into dwgs/scetches, sorry. Andre, if you don't mind send me your phone number via email. It is just a matter of understanding you are trying to tell me.
I have the engine on a testbench in my garage and use this to test the gen. I have everything connected except lighting and horn, or in other words there's almost no load while I'm running the engine. Since I am not always recharging the battery I should at least see some sign on the ammeter.
I'm thinking of converting my stand drilling machine into a gen tester similar as you showed me.
Thanks for getting me further.
Admittedly there are a lot of things in life that I do not understand....
http://www.ebay.com/itm/Ford-Model-T-Professionally-Rebuilt-Generator-With-Gear- /161241983677?_trksid=p2047675.l2557&ssPageName=STRK%3AMEBIDX%3AIT&nma=true&si=c LGatWHAn97FdqCah0TAkXF1a%252BA%253D&orig_cvip=true&rt=nc
why is this generator $268.00 when a respected vendor sells rebuilt ones almost $100.00 cheaper?
Is the core worth that much...just what?
There are many levels of "rebuild"...sort of like how "restored" on a car can mean either a paint job or a disassembled bolt-by-bolt rebuild.
The ad in the above link states "in fact this particular one had a new field coil installed", which tells me that they don't always get this part. I've never seen a generator with an original field that didn't need replacing, to where one could safely warrantee the item. So in this case, one might not know from generator to generator, what a "rebuild" would consist of. The bearings are sealed, but are they installed in wallowed out housings? Many front end castings are worn to where the bearings slop around. Was that fixed? Is endshake set or does the armature jump around? New insulators on the brush ring or just a little fishpaper cut and fit under the 3rd brush, waiting to short out? Is the old armature resurfaced undercut correctly? Even some new/rewound armatures from specialty shops still have to be reworked to keep from arcing, so it's not a given that if the work is done, it's done right. There are so many variables in workmanship and quality that must be addressed, it's hard for the layman to tell what he's getting other than rely on the reputation of the builder.
Retail, including a rewound armature, all new parts necessary to remanufacture a generator, comes to around $200, so for someone to get a generator "genning" for $168 as you've mentioned, and make a little $$$ for himself, at the very least, there is no new armature in that particular rebuild.
Personally, I don't know how on earth a vendor could purchase such an item from a rebuilder and sell it for a profit at that price unless they were doing it themself. And for the time it takes to rebuild one, and the time it takes to operate a retail outlet, I still don't know how it is priced that low. That said, perhaps I still haven't entirely answered your question.
You did answer above, and a known, respected builder did answer privately.
Seems that in purchasing a generator (or anything, for that matter) comes down to two things:
1) Definition of terms - a former President eloquently described that subterfuge, but more importantly,
2) what you said: "... rely on the reputation of the builder".
Must be vigilant when parting with dollars !
you're very welcome. I'm glad you got your answer.
with Andre's procedure of finding the neutral point (the gen was way off) and setting the 3rd brush and remedy of some other non-optimized things I finally found a very healthy generator generating.
thank you all.
Glad you got it fixed, thank you for posting a final update rather than leaving everyone hanging.