USA Trains Motive Power Main PageQuick links to major topics on this page:
Note: Click on the desired specific locomotive on the left. There are tips and techniques on each one in the menu. Variations and versions:Smoke units:
The newer products have fan-driven smoke units. You can see the fan motor, and they have a little power board either nearby, or on the chassis. These units work well and rarely burn out. The older smoke units are square and flat and will definitely burn out if left on with no fluid. They do not have fans. USAT Electrical variations:The type and method of lighting varies from loco to loco, and also several locos have different versions. Many of the diesels have classification lights that change color from green to red according to direction. Earlier locos tend to have low voltage lighting, 5 volts or so, and often a single set of 2 wires will power the number boards, the headlights and the classification lights. These usually use a large 2 pin connector. Newer locos will use a smaller 3 pin connecter (but not always) and use track voltage to this connector, and 18v lamps for the headlights and number lights. The cab lights vary also. The bottom line when converting a loco to DCC or something similar is to put the loco on rollers, give it DC, and then measure the voltage to the connectors and see if it is fixed or variable, reverses polarity or not, and what the max voltage is. Don't follow this advice and I will guarantee you will burn out lights during an install. Drive mechanism:
The drive mechanism is an axle assembly with a plastic gear with metal half shafts (that have the wheels) pressed into it. The axles ride in brass bushings. which ride up and down in the motor block. There is a wire that presses down on the axles between the bushing and the gear to pick up power. The ends of the axles ride in bearings in the side frames, which also have power pickup wires. Some locos, like the 3 axle trucks have an additional idler gear to change the gear ratio. Drive Problems:
The early units have splitting of the gear where the metal half shaft enters it (on either side). The fix is a new gear, or better yet a new axle set. As far as I can tell, the way to tell is the old axles have "splines" along the length. The newer axles have a helical knurling. The new ones still split the plastic housing, but not as often. There are some ways to repair them, see the section on "Split Axles" on the left. Many people just buy new axles. Also, the assembly/alignment of certain bushings is different between 2 axle trucks and 3 axle trucks. Failure to observe this and re-assemble properly leads to stripped gears. Many of the negative comments you may hear is from someone who actually screwed up their own locomotive, and then blame it on USAT. You are forewarned. Details in each specific loco page. Electrical systems:
USAT locos have very few electrical problems. The electrical pickup is at 2 places on each half axle plus the sliders. The only problem I have ever seen is when an extended short circuit has overheated the slider springs or the pickup "brushes" on the axles. This can overheat them and they will lose their temper. Overall a superior and redundant pickup systems. The wiring can vary, and if you will remember only one piece of advice: NEVER assume what voltage the lights are inside the loco, check the voltage with a meter BEFORE any alterations. Pickup Shoes / "skates" / sliders I have read that LGB pickup shoes can be substituted for the USAT ones. This could be helpful if your USAT loco's pickup shoes catch on turnouts, like the Aristo wide radius. The LGB ones are larger. This could also backfire, by being larger, can short to adjacent rail in turnouts past frog. Check carefully, several MTH customers have melted wheels by having sliders too wide. In my opinion, keep the track clean (or use SS!), swap out any traction tired wheels with solid ones, and remove the sliders. You still have TWO pickups on EACH half axle. Common USAT part numbers (note I have listed wheels in increasing size):Wheels & trucks: R2040 - wheel and axle set - solid - freight cars ( 2 axles) R22-011 - wheel & axle set - solid - NW-2/S4 (2 axles) R22-135 - wheel & axle set - solid - F3/GP7/GP9/GP30/GP38-2 (2 axles) (1.126" tread diameter)
R22-136 - wheel & axle set - w/traction tires - GP7/GP9/GP30/GP38-2/F3 (2 axles) R22-170 - wheel & axle set - solid - 44 Tonner (2 axles)
R22-171 - wheel & axle set - w/traction tires - 44 Tonner (2 axles) R22-419 - wheel & axle set - solid - end axles - SD40-2 (2 axles) (1.265" tread diameter)
R22-420 - wheel & axle set - solid - center axles - SD40-2 (2 axles)
R22-421 - wheel & axle set - w/traction tires - inner axles - SD40-2 (2 axles) R22-518 - wheel & axle set - solid - center axles - PA-1 (2 axles) (1.377" tread diameter)
R22-519 - wheel & axle set - w/traction tires - inner axles - PA-1 (2 axles)
R22-520 - wheel & axle set - solid - end axles - PA-1 (2 axles) R22-622 - wheel & axle set - solid - end axles - SD70 (2 axles) (1.461" tread diameter)
R22-623 - wheel & axle set - solid - center axles - SD70 (2 axles)
R22-624 - wheel & axle set - w/traction tires - inner axles - SD70 (2 axles)
Trim: R22-301 - F3 horn, set of 2R22-304 2 ea (F3 windshield wipers, set of 2)
R22-534 - PA air horn (pk of 2)
R2060 Brake wheels. 10 in a pack, Cost $3.95
R17PN - intermodel container pins (8 each) $4.95
R22-315 - F3 ladders (hang down below body and fall off all the time)
R22-333 - F3 air hoses (one unit of 4 hoses)
Coupler parts: R22-317 - coupler centering spring
R22-332 - coupler mounting block and pivot
Electrical:
R22-127 - screw in bulbs, number boards in diesels, low voltage - $3.50
R22-110 - gow bulbs for headlights in diesels, low voltage - $3.50
R22-17- sliders with springs
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