View single post by David Hoatson
 Posted: Tue Jun 4th, 2019 05:49 pm
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David Hoatson

Joined: Sat Oct 5th, 2013
Location: Chestertown, Maryland USA
The black goop may be the remains of a rubber grommet. Seriously. McMaster Carr or your local hardware store has new ones. 
I buy #11 exacto blades in boxes of 100. To change the headwire, carefully cut into the old connection. Be gentle. Unsolder the old wire or cut it. Make sure the old copper wire is super clean. Scrape any oxidation off of the area where you are going to solder the new wire. I use the super-flexible OTR headwire that you can buy from Twist the old and new wires together. Solder. I use a pistol grip Weller 100/140 watt. Tape the connection with cloth friction tape.  I tie a piece of lacing cord around the end of the headwire’s cloth sheath to keep it from fraying and getting loose.  Make sure you know the orientation and available space where the wire exits the motor case. Often, there is not much room. If you can, physically restrain the wire to the coil, using friction tape or lacing cord. 

To install the coil in the motor case, I buy long threaded rod from McMaster Carr. Thread them into the coil. Start sliding the coil into the motor, making sure the headwire is feeding though OK. Poke the 4 threaded rods through the screw holes in the case. Add a couple washers and a nut to each. Gradually tighten the nuts, pulling the coil into the case. Remember to watch the headwire so it doesn’t get pinched. Once in place, remove the threaded rods and install the real screws.