Been looking for video's of rebuilding a Generator. that would show the correct wiring of the brushes. and what and how to check everything without a growler.
The club sells a video for $14: http://modeltstore.myshopify.com/products/restoration-videos (includes the use of a growler, though)
Another good offer from the club is the manuals for $12 each, among them "The electrical system" which tells you most of what you may want to know on how to restore the generator and the ignition system: http://modeltstore.myshopify.com/products/service-manuals
This can maybe help.
Growlers show up all the time at both swap meets and ebay. They are just way too simple to not work. It would not be a major expense to buy one even to just rebuild your own generator - test a few spare armatures - and then put it back up on ebay. I know a fellow who got overloaded at Chicasha and instead of renting a trailer for a 1500 mile return home - he bought a new trailer across the street from Chicasha and pulled it home and sold the trailer for a slight profit. Way better than renting one for the same trip.
I agree with John. I bought my growler off of eBay for $20. I'm at the opposite end of the state or I would check it for you. Before I had my own growler I took them to the local starter alternator guy. He charged me $2 to test it as it only takes a couple minutes.
Chuck, we have a growler available in the Smoky Mountain T's.
Just to add to what John and Gary said.
You cannot adequately check an armature with an ohmmeter.
The only way (without some expensive equipment) to test a armature is with a growler.
There are two types of growler.
1.) In addition to the transformer, one also has a meter and and probes used to check current in each winding. This is a comprehensive armature test.
2.) The other type has only the transformer to excite any wiring so you can find loop shorts and this is not a complete test.
Try to find one with the meter and test probes.
Ron the Coilman
Ron is correct. The one I got has the test leads, meter and a light. Don't bid on the generic ones.
I have the club video and it shows how to check an armature using just a test light. That's what I did and it tested fine or is there something I'm missing here?
The generic term “Growler” describes a tool used to test generator and starter armatures. Growlers can have three basic functions.
All three functions are desirable to comprehensively test an armature.
1.) It will always have the capability to place a high strength magnetic field surrounding the armature and its windings.
2.) It may also have a set of probes with a low wattage bulb in series to detect low resistance shorts.
3.) It may also have a set of probes which can be place on adjoining commutator segments with an ammeter in series to measure current flow in each individual winding.
Now let’s discuss common armature faults and how the growler, if equipped, can detect them.
4.) Armature winding shorts to ground I.E. the armature shaft; the probes in item 2 above can be used to detect this kind of short. This test can also be easily done with a volt/ohmmeter. With this fault is present the generator will not provide current.
5.) Inter and intra armature winding shorts; by placing the high strength magnetic field surrounding the armature in item 1 above any inter and intra winding shorts can be detected. By explanation; each winding in the armature is normally open circuit. If a short exist the circuit is closed and the winding will create a magnetic field in the inter or intra armature shorted winding which can be detected by placing a hacksaw blade parallel to the winding lamination whereupon the blade will rapidly vibrate at the rate of the applied AC line voltage. Hence the name “growler” With this fault the generator may or may not provide current and the armature will like get very hot leading to early failure.
6.) Current flow in individual armature windings; the probes described in item 3 above can be used to measure current in each winding when the magnetic field described in item 1 above is applied. By measuring and comparing each adjacent commutator bar (hence winding) you can check current flow and for inter winding shorts. This fault will lead to overheating armature.
There is one other armature fault the Growler will not detect. It is referred to as a “flying short” This is where winding shorts only presents itself when the armature is spinning under the high centrifugal forces. Good luck with this one.
Ron the Coilman
Dave - as I remember the club video, the stator windings were checked with a test light only, while the rotor armature was checked on a growler and with a test light.
Ron has helped me do some rebuild work on my Generator, and his help was invaluable.
Sadly, it had to take a backseat to my health with my migraine headaches, which caused me to be bedridden most of the time, but I hope to get back on track with him in the future.
I have the the club CD that shows the Generator. A restoration video it is not. I consider it a primer to the workings of a generator and to testing to see if the generator and armature might be good.
But it does not show you how to restore a generator to new condition.
If that pisses somebody off, then so be it. Had I not sent my generator body off to have the field coil removed, I would have never gotten it out. And the CD makes no mention of this tool to remove them, nor does it show you how to re-tape old windings if necessary to do so.
People who make restoration videos have to remember that not everyone who works on their own cars has every tool under God's Sun to do a job, and just might want to see exactly what goes into an actual restoration/rebuild.
I'm not sure if the club's other CD's are like this since it's the only one I have, but maybe a more comprehensive set of videos could be manufactured.
I bought this Growler last autumn:
I believe based on above that I have a fine piece of equipment - problem is I have no manual soI do not know exactly how to use it.
Yeah I can figure out that I should put the apperture in the sadle - but then what?
There are 2 probes.
Rereading Rons post above gave me an idea how it should work. I'll give it a shot tonight.
I have a growler but hardly ever use it except to maybe verify a fault for someone else. If I receive a generator to restore, there's only a few things to check on the armature. One, is the commutator usable. Two, is the shaft useable. Three, is the stack usable and are the stack slots straight. After that, the coils mean nothing and it's just an exercise to test them. The armature either gets rewound or replaced with a new one.
Most of these armatures are approaching 100 years old and are guaranteed to fail with a shorted or open coil. The only question is when. A growler may be nice to have and it MAY help diagnose a problem but as Michael says; "then what?".
A growler is not something used by a restorer unless he's doing a rattle-can rebuild. And I laugh every time I see black electrical tape in a generator or starter.
Ken- When trouble shooting other persons problems I go through a check list of possible issues dependent on the symptoms. Often while going through the check list the person whom I'm trouble shooting will say "It is new!" and my response is "so!?!?". Just because you replace something with a new part doesn't guarantee it wont be a problem. A growler is a tool used to diagnose a possible problem whether the part is new or old. With that being said; Why do you associate a useful tool with being a shade tree mechanic?
I think being a Mechanic is more than replacing parts. It takes some brains to diagnose, and repair many parts. Often this means repairing parts to get a longer service life out of them. Now, I agree there is a point of no return on some things, but, I don't believe in replacing just for the case of replacing. I have gotten many serviceable miles out of original armatures that were tested on a growler, then turned on an armature lathe, then the mica undercut. Probably the best result is your wallet is a little heavier.
Perhaps you missed the bold word "restore". I wasn't talking about a repair. You certainly can't offer any kind of warrantee on an original armature. You're just "kicking the can down the road".
I've repaired one generator. It's not something I do as a normal service. I did it for a friend for the cost of a few the parts but the time spent was many hours and included replacing the field leads and rewrapping. It was fully tested and set.
I don't just replace parts for the sake of replacing parts. I replace parts to accomplish a goal. It's just that some posts are higher than others.
Ken- Why don't you consider restoring(repairing) original parts as good as new?
"It's just that some posts are higher than others." Can you clarify?
I admit I don't use my growler very often, but when required it is the only tool that will do the job.
In my view repairing (a service I do not provide), as opposed to fully rebuilding (a term some folks do not fully understand), Model T generators is fraught with danger. You cannot guarantee your work and then you own it forever.
Ron the Coilman
Mike - What I meant was; A post or bar--A standard of quality.
I don't see repairing the same as restoring. For me, restoring is placing something into a state as it was when new--Not just working.
A repair is only addressing a particular fault and the remaining conditions that may soon turn to faults go untouched. It would be like replacing a water pump on a modern 4-cylinder and not replacing the timing belt and/or idler while you're in there, if the mileage warrants it. The difference in price is only the part(s). It could save your customer thousands of dollars later. How heavy would the wallet be then?
How many people replace a burned out headlight bulb on one side and leave the other old one in? How many people replace only half the spark plugs? The answer will define that person's standard of quality.