TrainMaker

Copy this file 'TrainMaker.ms' to any folder in your system
Open 3ds max
Create a Spline Shape to use as track i.e. path
Create any object to use as wagon
Open 'Utility Panel' and click 'MAXScript' button
Click 'Run Script' and locate the TrainMaker script file
Select 'TrainMaker' in the 'Utilities' dropdown list
To automate this at startup - place the TrainMaker.ms file in
this folder: max_rootstdplugsstdscripts

Click 'Get Track' button - select a shape to use as track
Click 'Get Wagon' button - select any object to use as wagon
Specify the number of wagons with the 'Number:' spinner
Set the animation range use 'Active Time Segment from the Time Configuration
dialog. Or set the Start and End frame to any value.

The distance can be set in three ways:
1. Gap Distance: The distance between the wagons is calculated from the size of the objects x-axis and the value set in the 'Gap Distance' spinner. Regardless of the track length. If 'Follow' is selected in Path Constarint Options - the distance will be calculated from selected axis
2. c/c Distance: The distance between wagons are calculated regardless of the wagon size and regardless of the track length
3. Percent Offset: The distance is calculated from a percent offset of the track length. A Percent offset of 0 will distribute the wagons evenly along the Track

Orientation
- 'LookAt': will make the wagon look at the wagon behind. This prevents the wagon from slide off the path if the pivot is not at the wagon's center. LookAt overrides the Axis setting in the Path Constraint Options

- Tail: Creates a dummy as LookAt target for the last wagon
- Axis: Determines wich axis to use as LookAt vector
- Flip: Will flip the wagon's LookAt axis

Path Constarint Options
This is the same as the Path Constraint options in the Motion panel. The 'Follow' option will recalculate the Wagon Length according to the axis