164 lumber loader problem

[Penn Central]

Hi all I've gotten this accessory working by replacing all of the old wiring a few years ago. Has worked like a charm. I'm still really a novice with all of this. 

Recently I'm having problems with the motor. After taking it apart I'm finding the motor makes noise and tries to spin but cant. I apply power to each of the motor posts directly. Power goes through them to the brushes and commutator but struggles to spin. Cleaned the commutator and brushes. Tried reducing the pressure of the brushes to the commutator. 

Nothing. Could the motor just be going? It's the original. 

Thanks in advance!

[lionelsoni]

Do you understand that the motor components must be wired in series?  That is, one end of the field winding must connect to one of the brushes.  Then one terminal of the power supply (transformer) must connect to the other end of the field winding and the other power-supply terminal must connect to the other brush.

[Penn Central]

lionelsoni

Do you understand that the motor components must be wired in series?  That is, one end of the field winding must connect to one of the brushes.  Then one terminal of the power supply (transformer) must connect to the other end of the field winding and the other power-supply terminal must connect to the other brush.

 

 

Hmm . I'm thinking no. Can you explain a bit more? I thought one end of the power supply each to one brush. 

[lionelsoni]

The motor is a series-wound universal type, similar to that traditionally used in toy-train locomotives.  The armature and field windings must both be energized, because their mutual attraction is what produces the torque to turn the motor.  They are wired in series so that the same current flows through each component.  This is important for AC operation, because it forces the current to alternate synchronously in the two components.

Applying voltage only to one component, as by connecting the brushes to your power supply, produces no torque and can burn out the armature windings.  I recommend reading the excellent Wikipedia article "Universal Motor" to anyone who is interested in this topic.

[ADCX Rob]

Penn Central

Can you explain a bit more? I thought one end of the power supply each to one brush. 

No, it's a universal series wound motor.  Switch the brush connections to run the motor in the opposite direction.

 

[Penn Central]

Thanks everyone. Just following up after reading the above and tinkering with the motor the last few days. Got it to work again after understanding how these work. I kept one end of the power source connected to one of the posts at the armature as before. However the other end I connected on the other side of the motor field winding. So the current flows through the field winding to the post on the armature. Worked like a charm.   Thanks again!