Abstract: An improved thread-tensioning mechanism for the stop motion means of a multi-needle machine of a well known type wherein each needle thread, in extending from its supply spool to its needle, normally travels through a thread-tensioning section at a speed and tension which varies in proportion to its rate of variable usage within a given operating or usage range. Its tension variations are sensed by a sag sensor that shuts down the machine when the tension falls below said given range. In our improved thread-tensioning mechanism, a group of independently rotatable idler wheels is provided, one for each needle thread of a corresponding group of individual threads. The periphery of each idler wheel gravitationally engages and presses its needle thread against the periphery of a rotating shaft common to all wheels. Through this engagement, each wheel is rotated by and at the varying speed of its thread.