You cannot shrink or stretch the rails or change the distance between the ties or overlap them. The rails represent physical tape which will not stretch or shrink a useful amount. The ties represent timing pulses which must be exact in order to create the TV pictures at the proper rate. You cannot skip a tie, crowd any of them close together, or stretch distance between them. TV pictures are stable only because there is a constant, uninterrupted drumbeat of synchronization pulses holding them on the TV screen.
Any disruption makes the picture roll, tear, flutter, flicker colors, or break apart.
There are other anomalies besides bad edits that can ruin your voyage over the rails. Say some of the rails you layed were the wrong length, or were wavy. This is what you get when you are copying camera footage that has something wrong with it. The camcorder could have been damp and the tape sticky causing it to slide unevenly through the mechanism. The battery could have been low, causing the motor to run slightly slow.