I’ve noticed various amounts of back/forth play on my American Flyer motor armatures. I understand the need to add an appropriate-sized thrust washer to take up that slack, but just how much play/slack should there be? Should there be a certain amount?
I suspect that, as long as you can detect any end play at all after shimming, you are okay.
I was hoping for a few replies on this one as I have also wondered the same thing. Various supply shops (I use Port Lines Hobby a lot) have the bearing spacers. There is a surprising amount of play in an armaturee that is working OK. When a steamer runs faster forward than in reverse, the thrust bearing / spacer is often the issue. I’ve “re-curved” the thrust bearing with good success. Short of having a “standard” amount of play I could use a feeler on, I tweek re- assemble and run the engine till I’m satisfied. Not real precise, but has worked so far and untill I get a better answer.
I don’t know that there is a set number for clearence on the Flyer armature play, but I’ve had luck following Tom Barker’s guildlines in his American Flyer repair manual.
He states that there should always be at least one washer on the worm end of the armature and there should be some play. But he also says to check for interference between the commutator and the bruubes. If the bruubes rub on the commutator face, you’ll need a washer on the commutator end of the armature. I feel there should be a minimum amount of play, just make sure it’s not too sloppy.
I have been into slotcars since the 60’s and rebuilt many slotcar motors [ not the ho type] . The armature play, not too much and not too tight. A good hobby shop may have those spacers. Also check those motor bearings for wear, too much wear can contribute to excessive play.