subject: My Lego Train Wont Go Around the Track!! [print this page] So far the discussion has been straightforward. But I was not able to pull that 50 car train without bending the rules, or literally cutting corners. Any deviations from LEGO guidelines are done at your own risk, and most of what follows deviates from LEGO guidelines. So exercise proper judgment and precautions. First, let's return to the wheel holder. Whether you have a new wheel-set that drags from the first day or an old one that has worn out, the AFOLs also devised a solution, namely using a hobby knife to notch out the plastic where the wheels would otherwise rub on the wheel holder. I've used this trick on almost of my rolling stock. If the train gets too heavy, the LEGO magnets can pull apart. Assuming you are running on a loop and don't catch it in time, the front of the train can smash into the rear. You can eliminate the magnets altogether and use drawbars or shared trucks (e.g., the center of the TTX car, set 10170), but assembling the train becomes a lot more difficult. Another alternative is to use rare-earth magnets. On Lugnet, Mathew Clayson suggested using D61 3/8" x 1/16" from K&J Magnetics. Noting that "this size works very well, and isn't too fragile. On many occasions I've inserted these magnets between the standard LEGO magnets on adjacent cars to reinforce the coupling. When placing all of the motors at the front of the train, the forces drop off as you get further from the locomotives because there are fewer and fewer cars being pulled by that coupling. So you only need to reinforce the couplers in the front of the train, e.g., my 50 car train had these magnets between every car for roughly the first 30 cars. Rumors of other AFOL's using glue to stick the magnets together have floated around, but "glue" is a four letter word. Now let's return to that power equation. There are other ways to keep n small without shrinking the size of the loop of track. If the problem is simply a long loop of track, and not a heavy train, two or more power connectors (part 5306) from the same controller to opposite ends of the loop can shrink n in the denominator of the equation and reduce the power lost to the track. But care must be taken to get the polarity correct between the two power connections. Using multiple power connections also helps keep the train speed more even around the loop. When the train is really heavy or has more than two motors, a single controller probably cannot supply enough power. So instead of using multiple power connectors from a single controller, two (or more) separate controllers on a single track will increase the available power. But it becomes that much more important to have the polarity correct with the power connectors, and all of the controllers should be set to the same level and same direction. All four of the engines pulling my 50 car train had a single motor and power was supplied by two controllers connected on opposite sides of the layout. While the train made it around the loop under its own power, I had even more operational success when I cut back to 47 cars and added a fifth locomotive. In between, I added a third controller to supply enough power to the motors. The 47 car train ran for an hour before we replaced it with another train.
