R & R Field Coils

What is the trick to remove field coils (slotted screws) from old starters and generators?

Then, after they are re-wrapped, installing them so they are pulled up tightly enough so there is no interference with the armature?

You need a really wide bladed screw driver, and you need to but a lot of downward pressure on it to keep it from stripping the screw slot. They you need to gain some leverage on the screwdriver. I've used a crescent wrench on a square shanked screw driver, while leaning my chest against the end to put a lot of downward pressure. I've seen pictures of a fixture that has a bed to but the body of the generator in, with a levered handle with a screwdriver attached. You pull down on the lever to exert downward pressure.

To re-install the coils, use a hex head bolt with a washer to draw the coils up really tight and to conform them to the body of the generator. Once you've got it as tight as you can with the hex head bolt, remove it and replace it with the screw, drawing it as tight as you can.

I have had some success heating the screw head up with a pencil point torch then putting an ice cube on it. I like the idea of the hex bolt. Has anyone ever tried an exhaust pipe expander?

The proper tool to use is an "impact-driver". Select the right driver blade, set for left or right and one hit with a hammer either tightens or loosens the screws. I have seen many makes of these since I worked for GM in 1960. I bought mine a few years ago, its a T6348 Hammer Driver" and weighs about a pound. It came in a little kit about 1 1/2" x 1 1/2" x 7 1/2" and cost about $15.00. It sure beats playing around with makeshift things. Easier on the fingers and machine screws too.

As Pete O says.....A special blade bit and a press was used back in the day to R&R these very tight slotted pole shoe screws..

Try as above... that should work.

Get a cheapo impact screwdriver.

I got one as a gift many years ago.......made in China of course........but it's been one of THE most useful tools I ever had!

The proper tool to use is an "impact-driver". Select the right driver blade, set for left or right and one hit with a hammer either tightens or loosens the screws. I have seen many makes of these since I worked for GM in 1960. I bought mine a few years ago, its a T6348 Hammer Driver" and weighs about a pound. It came in a little kit about 1 1/2" x 1 1/2" x 7 1/2" and cost about $15.00. It sure beats playing around with makeshift things. Easier on the fingers and machine screws too.

A Google of T6348 Hammer Driver dosn't produce ant results. Is that the correct description?

Apparently I didn't read Tinindian's post well enough as both of us are recommending the same thing >>> https://www.google.com/search?client=opera&q=impact+screwdirer&sourceid=opera&ie=UTF-8&oe=UTF-8#q=impact+screwdriver&spell=1

Does anyone have any experience with one of these?

Just found this homemade tool on the Model T Forum made from a 3/4 inch bolt, pretty neat!

Howard Dennis

That is interesting. Sure easy enough to try.