AF Train Master

Hints for Repairing and Restoring Toy Trains

Number One: model electric trains are powered by electricity. "No kidding," you say. Given what I see coming into my shop, this observation is often either misunderstood or ignored. Take for example early "steam" engines manufactured by Gilbert under the American Flyer brand. Typically, they need both a thorough cleaning and fresh lubrication. Although the cleaning includes removing old lubricants, it also includes the wheels, axles and copper pick up plates on the underside of the tender! For electricity to flow, there must be good contact between the source and the motor. In the case of model electric trains by Gilbert, most often this means that current passes via friction contact from an energized track to metal wheels, to metal axles, to copper pick up plates, and then only via hard wiring. Dirt at any point in the system can impede the flow of energy to the point that motive power is diminished or even stopped altogether. I have seen "dead" engines come to life after merely cleaning the wheels on the tender. If you want top performance out of your model electric train, keep the friction points of power flow as clean as you can!

Number Two: "e-units", an often maligned part of the Gilbert "steam" engines, are the mechanical devices which provide a forward/reverse capability to the train. The units consist of a "rotating drum", covered with small copper strips, two sets of "fingers", which make contact with the drum, and a solenoid which drives the rotation of the drum via a small metal lever. When power is applied to the train, each on/off cycle of the transformer activates the solenoid which in turn rotates the drum. Each rotation of the drum changes the orientation of the copper strips to the fingers, thereby altering the flow of energy to the motor such that the engine moves either forward or backward. It is a simple device, but it is a mechanical device and as such is prone to dirt and wear. In my experience, the e-unit needs only to be serviced (with great care not to bend the tiny copper fingers). Occasionally, parts need to be replaced and or the unit needs to be rewired, but due to the nature and age of e-units, great care must be given when soldering new wires to e-units lest the points of contact snap or break. A drop of oil on each side of the rotor's axle, on each side of the solenoid's flap, and on each side of the drive lever typically will get the e-unit functioning reliably. I will also put one very tiny drop on the end of the drive lever where it makes contact with the cogs of the drum. In the shop, I insist on one hundred cycles of the e-unit without any sticking before I consider the unit ready for service. This is most easily accomplished by disconnecting the wire from the track trip and tapping it directly to the rail of track repeatedly -- saves your transformer's mechanism and can be accomplished quite rapidly. Electronic devices which provide the same functions as an e-unit are available for those who wish utmost reliability with minimal need for service, but the electronic units lack the audible clicks which come from e-units, and, finally, they are not "original equipment".

Number Three: the motors of Gilbert "steam" engines are comprised a magnetic field, a rotor and a brush assembly. When an engine does not respond when placed on track and energized, the first step in diagnosis is to isolate the source of the dysfunction. For this next test step, it is very helpful to have a static engine testing device which enables the engine wheels to turn without the engine itself moving either forward or backward. You can do this by sitting the engine block on a small piece of wood elevating the wheels off the ground, by holding the engine in one hand while energizing with the other, or by using a very cleverly designed testing device complete with ball bearing assemblies which enable the engine to "move" while sitting still. The best such device I have seen is the "EZ Engine Test Stand", manufactured by Dave Balts & Associates of Chetek, WI. Disconnect the tender from the engine and apply test leads directly from the transformer to the wiring harness of the motor, taking care to avoid short circuits (see # 4, below). If the motor works with direct connections, you can assume that the problem lies somewhere before the engine -- either the track or within the tender and its wiring. If the motor does not respond under direct power, it is time to take the motor apart and clean it thoroughly, including a thorough lube and oil of all moving parts. It is sometimes necessary to service the commutator of the rotor, a job best left to professionals who have precision equipment, but you can safely wipe the surface of the commutator with a soft cloth to remove any surface gunk. Clean and/or replace the brushes. Loosen the cotton tip of a Qtip so that you can elongate it, thereby reducing its width. Push the elongated swab through the tubes which hold the brushes to clean the tubes of carbon and other residue. The brushes are held against the armature with very light duty springs so the tubes need to be clean. Thoroughly clean the brush housing assembly. Inspect the brush housing to make sure that there is no wear apparent on the ends of the brush tubes or the bushing which holds the end of the rotor. Apply a drop or two of oil to the wick. When you reassemble the motor, be sure that the washer is still on the screw (worm) end of the rotor, and gently twist same back into the drive gear until the wheels begin to turn. (Note: it is my observation that the quality of replacement brushes varies so be sure to order your parts from a reputable supplier.)

Number Four: to test the motor with direct connections to the transformer, you need to know which wires to energize and which to jump. Additionally, if you wish to minimize short circuits you will need to fabricate two test leads using four pin male connector strips, one for forward and one for reverse. (Note: engines with e-units in the engine housing, such as the Royal Blue and some "smoke-in-tender" freights", require a different solution but the principles are similar.) To fabricate test leads, take two eighteen to twenty four inch sections of wire and solder them to the right and left most posts of a standard four pin male connector. Take a small piece of wire and jump the remaining two inside posts. Connect the long leads to the base post and the variable (middle) post of the transformer, connect the four pin connector to the engine, and energize. The engine should "move" forward. Take another two long wires, but this time solder them to either the right most two or left most two posts of the four pin connector. Using a short length of wire, jump the remaining two posts. Connect the two long wires as above to the transformer, push the four pin connector into the engine, and energize. The engine should "move" in reverse. The same effect with far less effort can be accomplished using lengths of wire and alligator clips, but, unless you are very careful you will encounter the occasional short circuit and perhaps also a small shock or two along the way.

Number Five: lubrication of moving surfaces is critical to the operation of your train -- the motive power of your train is severely diminished by too much friction. Friction between moving surfaces will cause your motor to run warmer than it should and performance will deteriorate. You will need a very good grade of machine oil, and a lubricant. Apply the lubricant to the main drive wheel and rotor shaft -- typically there is a small access door on the underside of the engine housing. Oil all moving parts, pistons, rods, etc. One small drop of oil at each point is sufficient. Be very careful to apply a thin layer of oil on the inside of the choo-choo portion of the smoke unit if your engine is so equipped so that the plunger can move very freely. Be careful to get the oil in the right place -- you do not want oil dripping onto the wheels and making its way onto the track. Because your engine typically will be asked to pull a load of cars, it is a good idea to oil the wheels of your cars where the axles sit in their side housings. The more you reduce friction in your train, the easier and faster your engine will operate. The original operator's manual which Gilbert shipped with their trains says it this way: "In this age of machines, everyone is familiar with the importance of proper lubrication. ... This train of yours, like its prototype, must be kept well lubricated at all times to insure perfect performance, long life, and to be maintained at proper operating efficiency. To do this we recommend that your locomotive and cars should be oiled every four hours of actual operation; also, before operating when you fist get the train, and after is has been put away for any length of time."

If you have questions, please feel free to contact the brothers: jim (at) aftrainmaster (dot) com, and/or john (at) aftraimaster (dot) com.

dirty and clean wheels


eunit drum

eunit fingers

field rotor

brush assembly

rotor armature


elongated qtip

diagram of wiring cheat

four pin connector strips, male and female

cheat wire for forward direction

exposed engine with smoke unit