HOW TO SERVICE MODEL 3 AUTOMATIC MIXMASTER
A.
Taking the Motor Apart
The parts referred to in this bulletin are illustrated on the diagram attached
to the end of the bulletin with parts list. The tools that will be mentioned
are described on page 9. Threads on all screws and other fasteners used in the
Model 3 Automatic are right hand, except armature thrust adjustment cap (see
Key number 107 on parts diagram), which is left hand.
A-1.
To take off switch knob (key number 70) in rear of motor, remove switch knob
screw (119.). Pull out knob, also take out round fiber switch pin (325) and.
square speed adjustment cam pin nut (136) and cam pin (137).
A-2.
To remove rear motor cover (128), turn out the two round head rear cover
screws (65) at the bottom (short screw) and top (long screw) of cover. When
removing cover it may be necessary to tap it a little to break the seal caused
by the paint sticking where the cover joins the motor housing.
A-3.
To take out Bakelite governor assembly (100), first remove the three nickeled
mounting plate screws (91) and two of the binder head screws (122), which
fasten one lead wire to the switch lever (105) and one to the governor
diaphragm (138). Pull out Bakelite governor assembly while guiding the two
lead wires carefully through the slots at the outer edge of the Bakelite disc.
Care should also be taken not to break or lose the thin rubber gasket (116)
fitted around the circumference of the Bakelite disc.
A-4.
To remove the fan housing and rear bearing bushing assembly (key number 135)
unscrew the three hexagonal fan housing retaining studs (130) –1/4 in. wrench
is used for this purpose - and pull out fan housing, using pliers if
necessary. Be careful of the two wire leads.
A-5.
Now remove both armature carbon brushes (19) by unscrewing black Bakelite cap
brush screws (16) on outside of motor housing. Exercise care in not letting
brush springs (17) or brushes jump out end get lost.
A-6. To loosen the baffle plate (132) turn out the two flat head baffle plate-
retaining screws (23) and remove rear cover locating key (131).
A-7.
Armature assembly (27) may now be removed, together with the fan (133) and
baffle plate (132), without disassembling the parts in the front of the motor,
by just pulling out the armature assembly. NOTE: If it is planned to fit this
assembly back in the motor without adjusting the parts in the front of the
motor, care should be taken to prevent any change in the original relative
position of the two whipper spindle s1eeves (13 and 20), otherwise the spindle
sleeves will get out of alignment and the blades on the whippers will strike
each other when turning. See Section B2A for proper method of fitting armature
assembly into the motor without removing parts at the front.
A-8.
The fan (133) can be taken off the armature by removing fan retaining nut
(134). 7/16 in. wrench may be used for this purpose. Turn nut to the left.