06-11-2021, 12:26 PM
It is not to difficult to rewind field coils once out of the Dynamo.
1. Fold the coil flat and make a wooden block the same size and thickness of the rectangular hole that will fit inside the windings. Put a hole n the centre of the wooden block.
2. Make two plywood discs with a hole in the centre. Put a bolt through the disks with the wood block in the centre to male what looks like a crude spool. Cut four slots in the spool sides wide enough for the width of a piece of string and cut towards the centre of each face of the spool.
3. Chop through your old windings then count the number of turns that make the coil. Carefully clean 2 or three strands of wire to remove varnish etc. Measure with a mic to establish the gage if wire.
4. Return to your crude winder and put string through each pair of holes ( This is to temporarily hold the coils when made.)
5. Put the wooden spool in a slow electric drill by means of the bolt. Leaving a good amount of spare wire to act as a fly lead start to wind on your new wire counting the turns and keeping it tight until full amount achieved. Tie up the strings to told the windings in place and dismantle the pulley. Remove former block and tape up the windings with cotton tape removing the string as you go on. Shape the coil to an arc shape to fit the iron core.
6. Finally leave in a bath of shellac overnight before baking on a slow heat for about six hours.
I have not done this to an A7 but as an apprentice to many electric motors and dynamos.
John Mason.
1. Fold the coil flat and make a wooden block the same size and thickness of the rectangular hole that will fit inside the windings. Put a hole n the centre of the wooden block.
2. Make two plywood discs with a hole in the centre. Put a bolt through the disks with the wood block in the centre to male what looks like a crude spool. Cut four slots in the spool sides wide enough for the width of a piece of string and cut towards the centre of each face of the spool.
3. Chop through your old windings then count the number of turns that make the coil. Carefully clean 2 or three strands of wire to remove varnish etc. Measure with a mic to establish the gage if wire.
4. Return to your crude winder and put string through each pair of holes ( This is to temporarily hold the coils when made.)
5. Put the wooden spool in a slow electric drill by means of the bolt. Leaving a good amount of spare wire to act as a fly lead start to wind on your new wire counting the turns and keeping it tight until full amount achieved. Tie up the strings to told the windings in place and dismantle the pulley. Remove former block and tape up the windings with cotton tape removing the string as you go on. Shape the coil to an arc shape to fit the iron core.
6. Finally leave in a bath of shellac overnight before baking on a slow heat for about six hours.
I have not done this to an A7 but as an apprentice to many electric motors and dynamos.
John Mason.
Would you believe it "Her who must be obeyed" refers to my Ruby as the toy.