Does anybody know how to get the 4 pole screws out (the four screws that hold in the pole pieces and the coils) off of a generator? I'm taking apart my generator to rebuild it, but I can't get the dang screws out! I've got the Model T Ford Service booklet, and in it they talk about a device to be used in a vise to remove the screws. Does anyone know if this can be purchased anywhere, or how it can be made? It looks to me like a screwdriver bit that is clamped in a vise against the generator, and then a wrench is used to turn the bit. I tried this, but I've already broken a bit trying to get the screws out. Any help is appreciated!
Those screws are staked and you must remove the staking before trying to remove the pole screws. I would strongly suggest you box it up and send to Ron patterson, he has the tools to remove them and to properly reinstall them. The clearances are very important .
After removing the staking, a hand-held impact driver will take them right out.
Here's what they use.
Removing and installing pole shoe screws are a problem if you do not have the correct tools. With the tool above they are very easy to break the force overcoming the staked area. You can also use Seth's method.
In addition to the tool shown above when installing a new field winding you will need a pole shoe spreader. This is required because the shoes must be pulled down to a specific location to ensure the correct magnetic coupling between the armature and shoes. There is a go/no go gauge to check the correct diameter.
I have all these tools and if you need help let me know.
Ron the Coilman
I forgot to mention.
The pole shoe removal and installation tools referred to in the Ford Service book were made by Allen Electric Company. I have set of those tools too, but I never use them because the mouth of the vice jaws required to use them is, as a practical matter for a home shop, not available.
I would suggest you not try to use a impact hammer to reinstall the pole shoes without a go/no go gauge or you will only make a mess of things with little success.
Ron the Coilman
Thanks for the info Ron...maybe this type of thing is better left to the pro's. Seems like I'm always getting myself in over my head!
As an electrical tradesman I have to qualify my advice... the nature of the trade means the really fussy blokes succeed best. They can be a little too fussy though... lol.
By all means give it a go... as much as there are very good tools featured and proper methods mentioned you can achive a satifactory result with an impact driver and some care and attention.
I have seen felow tradesmen simply use a big hammer to break the pole screws off and replace them. Conversely I have had to drill some owing to corrosion and lack of groove to drive them with.
I have smashed cheap impact driver bits, both plain and phillips, over the years. They are tempered and are a little tempremental. Seek out the local Snap-On bloke for one of his bits even if you don't buy his driver. Try getting the long style, conventional screwdriver blade one. The short dumpy ground hexagonal jobs seem to be more brittle despite their bulk.
Using old field coils or new ones, I like to have them varnished. Though this can give them some unwanted lumps or overall bulk, they can be sanded down and it does really make them bulletproof. Varnish is an even better thing for armatures.
A dremel can be useful to remove the staking, depending on how many times it's been apart before, but it's not critical.
The critical thing when reinstalling them of course is to make sure the armature will revolve freely inside the generator. The idea is to have the shoes as close to the armature as possible, without them coming into contact, remembering the thing will change shape slightly when it's hot.
Ron does mention plling the shoes down to a specific location to ensure magnetic coupling. This is a good point but we are talking about parts mass produced 80yrs ago, with 80 years experience on them.
If it were a Smiths or C.A.V. item from an early Rolls Royce or Bently then the inside of the carcass will be perfectly true, the shoes would be ground to suit that diameter and when assembled the inside of the shoes would be machined true as well. While I'm sure Ron doesn't mean to be disbaraging, the point he's made is that it's all about tolerance, and provided you have some a model T generator will work satisfactorily.
Give us a yell if you need more help.
So...I feel kinda dumb for asking this, but what exactly is the staking?
Well, you fire up the BBQ and then you put some beef on it. . ..
Sorry, couldn't resist! Staking on the starter screws is where a sharp cold chisel has been used to upset the case metal next to the screws to keep them from turning--think of it as a very inexpensive cotter pin (no pin needed, just strike the case and you're done!).
Is this clear as mud??
Unless you plan to drive a lot at night, you won't need the generator. The magneto can be used to recharge the battery while powering the coils at the same time.
Obviously not a Model T genny, but it shows the concept of staking screws to keep them from coming loose.
Staking might be compared to what might be called "buggering up the screw threads a bit". It always seems like sloppy work to me, but that's how ol' Henry designed (or had engineers design) lots of things, right?
All this makes me think about my recent installation of a new pawl in the brake lever of my '23 touring. (Quadrant was okey, but the pawl was completely worn out) The pin thru' the hand brake lever that the pawl pivots on fit fairly snug, but not really what you'd call a "press fit" or an interference fit. Wasn't sure how (or if) to secure the pin. (???) Maybe this would have been a good place for Loctite, huh? I'd tell you how I actually secured the pin, but then I'm really not too proud of it so I'll just let it go......
Sorry Brett; didn't mean to send your thread off on a different direction.