american flyer franklin 88 hot engine

[rlassoc12]

I converted a franklin 88 to dc with a bridge rectifier. The field coil now gets very hot. Anyone have this problem?

[Laurastom]

I will restate the question to be sure I understand it. The 88 has a series wound universal motor so it will run on DC track power with no modifications, however the reverse unit controls the direction. I am assuming the reverse unit was replaced with a bridge rectifier to allow track polarity to control direction.

For this to work the field still needs to be in series with the armature. If it is not the field will seriously overheat. One side of the field is connected to the track power pickup and the other side of the field is connected to the bridge rectifier input. The other input terminal to the bridge rectifier is connected to the other track power pickup. The armature (brushes) are connected across the bridge output terminals.

This wiring diagram is Figure 6-13 on page 49 of Tom Barker's repair and operating guide for American Flyer.

For long term operation of a Gilbert steam engine in a DC environment I would install one of the bolt it can motor kits rather than stay with the old open frame universal motor.