Bacon slicer advice needed

[Dennis Nicholas]

Hi Hedd

At the starting handle the engine turns clockwise,  looking from the cockpit the flywheel turns
Anti-clockwise, so the starter pinion needs to turn clockwise....
but it’s not it’s spinning anti-clockwise......

The opposite of what it needs to send the pinion along the spiral thread?

Still bemused!!

Regards

Bill G

Bill you have the answer already.
1. Since you say the pinion needs to turn clock but it is turning anti-clock AND the gear is flying in instead of out on the bendix to the flywheel then a. the bendix is the right thread and b. the motor is thus turning backwards.

Assuming negative earth I will call the main terminal the +
2. The motor action works with two different components: a. field coil windings  b. Rotor windings (with commutator segments that the brushes sit on)
a. electricity flows from + terminal which is connected to one brush and to one end of the field coils (the field coils are composed of a single length of wire from the + terminal wound round a former  and then on to a second coil on the other side of the motor body (both field coils are mounted on a solid separate pole piece) then connected to the motor body..ie earth or negative.)
b. The electricity flowing in the field coils makes one Field winding (and pole piece) North and one pole South......a magnetic field FORCE exists between the North and South.  (The field coil can be wound in two different directions so making a N or S pole)
c.  Electricity flowing from + terminal goes through the brush onto the commutator,  through one of the several windings forming the rotor to the commutator segment on the opposite side of the commutator and through the second brush and wire connection to the motor body: thus there is a loop of wire carrying a current which is lying within a magnetic field force.
d. That current in the commutator loop makes its own magnetic field FORCE which reacts with the N/S FIELD COIL force to move the commutator wire loop........direction of travel depends on direction of the N/S magnetic field from the field coils and direction of current in rotor windings.  Thus change EITHER N/S poles or direction of current in rotor windings and you change the motor direction.

c. To change N/S polarity and thus direction of rotation, take field winding connection from + brush terminal and connect it to motor body AND remove the other end of the field windings from the motor body and connect it to the + brush terminal.

ALTERNATIVELY

d. Take one brush connecting wire off the + terminal and connect it to the motor body AND take the other brush connecting wire off the motor body and connect it to the + terminal.

I know you say you have not touched internal wiring but as suggested someone else may have, including the field coils having been re-wound the opposite way round but with the same length of wire sticking out each end so they appear to be connected correctly to + and body because each length only reaches those terminations.

(To the knowledgable....yes I know electricity...i.e. electrons actually travel from negative to positive but that may just muddy the waters here  )

Sorry it seems a bit long winded (and maybe a bit simplified) but if you need any of it further explained just ask.

Dennis   (retired sea going professional electronics/electrical engineer)