Nothing is more frustrating than having to push and prod your train around the track. Fixing poor model train operations becomes much easier once you learn to diagnose the causes. Model trains depend on the rails for their power. Trains will slow down or stall if that connection is broken. If your trains aren't maintaining a consistent speed around your layout, there are a few probable causes and some simple solutions.
If you notice problems right away, your trains probably aren't getting enough power and you need to improve the flow from the power supply. This voltage drop can be easily corrected by adding more connections. It is common for trains to run well for a while and then get progressively worse. Dust is a great insulator, and try as we might it is always around. Your layout needs regular cleaning to keep in running. Keep the care and cleaning of your railroad in mind from the begining. It is hard to clean track you can't reach.
Voltage Drop: If your train slows down or stops only in certain spots, the problem is probably voltage drop. Distance and the joints between track sections weaken the flow of power. Tighten any loose joiners and if necessary, run a second set of wires from the power supply to the track in the troubled area. Make sure to connect each wire to the proper rail.
On large layouts, and with most DCC systems, a bus wire with feeders to multiple track sections is recommended. Using a heavier wire, No. 14 to No. 10 depending on the scale and length of run, is much more efficient than the rails themselves. Smaller feeder wires between the rail and the bus, No. 20 to No. 18 gauge, can be attached as often as necessary. Typically, feeders are attached every six to twelve feet.
You can also solder the rail joiners themselves. This will greatly reduce voltage drop and also help eliminate kinks that can cause derailments. It is a good idea to leave a few joiners open to allow for expansion and contraction throughout the year.
Cleaning Track and Wheels: The most common cause of sporadic running is dirt. The first sign of problems is usually a flickering headlight. Soon your locomotive will be stalling, especially at low speeds. For really good operation, both the track and the wheels need to stay clean.
Track can be cleaned with abrasive and liquid cleaners available at hobby shops. You can also buy specially equipped cars to do this work for you while you run your trains. Just remember to clean or replace the pads from time to time. Rubbing alcohol and cleaners like Goo-Gone™ also work. Never use steel wool to clean your track. The small metal shavings can be drawn into the armature of the locomotive's motor causing damage.
Wheels can be cleaned by putting a liquid cleaner on a paper towel across the track. Run cars back and forth across the towel until clean. Metal wheels stay clean much longer than plastic. They track better too. Replacements come in all sizes; your hobby shop can help find the right ones for you. If your locomotive picks up power from all wheels, you can put one set on the towel and one set on the rails. Hold on to the locomotive and turn up the power. When one set is clean, switch to the other. Contacts or wipers between the wheels and the motor also need cleaned occassionally. These can be hard to reach, but a can of compressed air and a drop of a liquid electronics cleaner usually do the trick.
Perhaps the easiest and most enjoyable way to keep your trains clean is to run them. Believe it or not, trains run better when they are run more frequently. So if you spend more time running you should spend less time cleaning.