Specifications

76
A loop is made at the end of the first coil and the beginning of the second coil. The second
coil is started in the designated slot and the coil is wound with the same number of turns as in
coil 1. The span of coil 2, has to be equal to that of coil 1. When the second coil is finished, a loop
is made again and then the third coil is started. In this manner the winding is continued, until all
the coils have been wound. The end lead of the last coil is connected to the beginning lead of the
first coil. After the entire armature is wound, there will be two coil sides in each slot, in double
layer winding. It has to be ensured that all the coils have the same pitch and turns. The loops
made at the end of the coils will look as shown in Fig. 6.3, and have to be connected to the
commutator raisers. The procedure of making loops while winding, explained here, is for simplex
lap winding. This method is usually adopted for small armatures. For wave winding and multiplex
windings, connection for raisers shall be taken from the coil ends according to the winding
pattern.
Formed coil winding: For this method, wooden formers are made to the dimensions of the
armature coils, similar to those of the field coils in section 3.4. The total number of coils required
for the armature are wound and kept ready. The inactive side of the coils is bound with tape and
tied with cotton strings as shown in Fig. 6.4.
The active side of the coil is spread as in Fig. 6.5 and the coil sides are inserted in the
respective armature slots, conductor by conductor as shown in Fig. 6.6. Similarly all the coils of
the armature are placed in the respective slots and the coil ends are looped and soldered to the
respective commutator segments.
Fig. 6.4
Fig. 6.3