I'm repairing a 300 engine and when I took it apart I found that there weren't any thrust washers on the armature assembly. Can anyone tell me what size I need if any?
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As many to remove most of the end float on the armature.
ok thanks
@Tom Haberman posted:ok thanks
You want to make sure the armature still has the ability to achieve magnetic center to the field windings. Otherwise you lose efficiency and generate excessive heat.
@Ukaflyer posted:As many to remove most of the end float on the armature.
Tom, As you add the washers, take note as to their placement and move from one end to other to get best performance of motor. You may find that motor will run slow in one direction or the other with washers, try moving a washer to the other end of the motor. The motor will require some end float for free running.
Ray
Most often (1) 0.020" thrust washer in the front and (1) 0.005" in the rear if it has an oil slinger. If no oil slinger then no washer at the rear. (that's factory) Sometimes (2) 0.020" in the front. If you're spending a lot time dinking around with washer combinations to balance or gain motor performance it probably has more to do with the condition of your commutator plates and/or brushes and brush springs. If the comms have a trough worn in them or are cupped at their segment gaps you're probably experiencing faster-in-reverse (the "syndrome" and not uncommon). Reface the comms, get them replaced, or change out the armature with one in better condition (preferably NOS). In any case, replace the brushes and springs while you're at it - cheap and worth it.
Please let us know how it turns out; FWIW, my (2) 300 locos run as well as any of my other early PW Flyer steam... which is to say, very nicely! 🙂
Mark in Oregon
