Motive Power Mods & Tips

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This is the "entry point" for all pages on working on and modifying/improving all brands of motive power.

I STRONGLY recommend you read this page first.

Your next step is to select a manufacturer from the menu on the left to see what tips are available for that manufacturer's products.

Don't forget to visit the "Misc. Motive Power" section, lots of good information that apply to motive power.

I don't have any particular agenda, but I'm telling it like it is. If you want to "drink the Kool Aid" then join a manufacturer's forum and take everything the manufacturer says as gospel.

Most of the entries are from my direct experience. As always, I have an eye towards low maintenance and reliability.

Note: I have not found ANY brand that I buy that does not need some form of "tweaking". The difference is that some brands need more than others. In most cases, you pretty much get what you pay for. Don't be upset, be forewarned, and realize there's a "fix" for almost everything.

My experience - out of the box assembly / quality

  1. LGB (limited) - rarely a problem, better metal, plastic, quality control. Worse since Chinese manufacture. Hungarian stuff better, but not as good as the original.
  2. USA - hardly ever a problem except for "split axles" on older locos, and NOS (New Old Stock) which often happens.
  3. AML - Rolling stock excellent, the locos are great, but of course are brass locos and more costly. Tighten side rod screws!!
  4. Bachmann - I have had very few problems out of the box, but mechanical drivetrain issues (split gears) are not uncommon. Some crapy soldering.
  5. Aristo - normally not any problems in the basic design, but  more wiring and electrical problems and more assembly problems than the rest. Poor QA.

My experience - after running for a while

  1. LGB - rarely a problem
  2. AML - rarely a problem.
  3. USA - only the split axles, easy and cheap to repair
  4. Bachmann - split gears, loose screws, cracked plastic housings
  5. Aristo - more broken wires, wheel plating prematurely fails and steel wheels rusting, wheels coming loose on axles, destroyed valve gear. Strange electric issues, each new run has something put together wrong that you may not find until you use the "socket".

My experience with service

  1. LGB (old) - (the repair center was walking distance) - took forever to fix things, but perfectly repaired.
  2. LGB (new) - well there are a few places that have LGB parts. Try Train-Li or Massoth, both do quality work, but don't expect USA prices.
  3. USA - I have never had to send anything back, the only repair parts I have ever needed were axles, easily repaired or replaced. Mike in parts is golden.
  4. Bachmann - heard too many horror stories to return, and replacement parts easy to get, although have to buy assemblies sometimes $$. Irvin in parts has retired, bad news, you normally get a snotty person on the phone. They DO stock parts.
  5. Aristo - they are gone, hoping Bachmann will produce some stuff. When they were around many people had sent things back 3-4 times and not repaired. They used to have a great reputation, but just ask a mallet owner. The bright spot was Navin in service, the nicest guy you know. He's now with Precision RC, who bought the Crest line.

Typical things you can do to improve your motive power:

Gauge your wheels

Unfortunately easier said than done on many locos. USAT is easy to do. Aristo is about impossible and normally way under gauge. (Exception, the 2013 run of Dash 9's are PERFECT) The prime movers need to be completely disassembled and a shim added between the gear casting and the half axle.

It's worth the effort in smooth running and reducing derailments.

Add weight

If there is no problem with premature bearing failure, add weight up to prototype weight on rolling stock.

Scale weight is calculated by using the cube of 29 (in my scale)... either multiply or divide by it.  The number is 24389, divide the prototype weight by 24389 to get scale weight in pounds.

For example, an E8 weighed 187 tons, or 374,000 pounds. Divide by 24389, you get 15.3 pounds.

A nice easy number to remember is it is approximately 1.3 ounces of weight per prototype ton.

You may surprise yourself, adding 3 of the original 2 pound weights brings the E8 very close to 15 pounds for example .  

On locos that have ball bearings on the axles, you can safely go to "prototype" weight. Fro locos with sleeve bearings on the axles, you need to be diligent on keeping things lubricated and inspect for wear.

Go over electrical connections

Many of the latest locos have sloppy wiring, soldering, and pinched wires right from the factory. A visual once over will help.

Look for cold solder joints and re-do.

A major source of broken wires is where the wires leave circuit boards, especially where the wires will move, like when connected to a motor block. A dollop of hot glue right where the wires leave the circuit board will be a good strain relief.

A note on DC operation: the NMRA standard says that a loco should move forward when the right hand rail is positive. Note that LGB locos run in the opposite direction. Most people follow the "LGB" / G scale standard.

Protect from shorts (track power)

A common problem with track power is a short circuit when you derail a locomotive. When this happens on a switch, one of the trucks will go in the wrong path, and will be presented with the wrong polarity.
What often happens is a short circuit from one set of wheels to the other. This usually destroys some wiring or circuit board traces inside.

A  way to protect from this is to put some kind of fuse on the track pickup leads. Normally one fuse per each track pickup wire will work.


I'm experimenting with a "polyswitch" which is basically is a thermally activated self-resetting circuit breaker. Many manufacturers use them for this purpose, but unfortunately not exactly wired in the right way.

I've been trying some low resistance ones RUEF300-ND which were about 35 cents each in quantities of 100 from Digikey. The polyswitches used by Aristo have an "on" resistance of about 0.8 ohms, which I think is excessive in comparision to the resistance of the motor. These are abut 0.25 ohms. They are rated 3 amps, but look at the data sheet to understand at what currents they cut out.

So far the results have been very good, read this page on a typical installation:

RS-3 improvements and PolySwitch overload protection

A very nice page on different large scale motor blocks of different manufacturers, intended for "bashing" but helpful in many ways:


Sub pages

Click the links below to go "deeper" into details on individual motive power by manufacturer

Weather Underground PWS KCACARLS78