Jigs and Moulds

This section describes how to make the jigs and moulds for building a PMG. Once you have made them, they can be used again, to build more PMGs.

Coil winding machine

Some coils for the stator

The PMG stator contains six coils of copper wire (see diagram 4).

4. COIL

110mm

1 00 TURNS OF ENAMELLED COPPER WIRE

0mm

The coils will be wound on a plywood coil-former.

The former is mounted on the end of a crankshaft, between cheek pieces.

Make a crankshaft, turned by a handle (see diagram 5).

HANDLE

5. CRANKSHAFT

A

A SIMPLE 4

' BEARINGS '

Cut a small flat steel plate 60 x 30 x 6 mm (suggested sizes) and fix it securely or

weld it to the end of the crankshaft as shown in diagram 6.

Drill 2 holes, 6mm diameter and 40mm apart, centred on the shaft.

6. STEEL PLATE

Cut out 3 pieces of 13mm plywood as in diagram 7.

7. COIL-FORMER AND CHEEK PIECES 125

125

125

The coil former is 50mm by 50mm by 13 thick. It has rounded corners. The two 'cheek pieces' are 1 25mm by 1 25mm. There are 20mm wide notches top and bottom in each. The notches are for putting masking tape under the coil, so that it can be taped up before removing it from the former.

• Stack the pieces with the notches in line (diagram 8), and drill holes for the

mounting bolts.

The holes are 6mm diameter and 40mm apart. Use a drill press to drill the holes exactly square to the plywood.