MECHANICAL TENSION SYSTEMS

The mechanical machines that are mostly used by professional stringers have a completely different tension system: The linear tension system works with a crank and a reference spring. In the tension system of the foot-operated Stringway MS 200 a heavy spring pulls tension. The main difference between the two systems is that the Stringway machine works with a “constant pull” action, the importance of this is described below.

ELECTRONIC TENSION SYSTEM

Electronic stringing machines have a measuring system that “tells” the drive system to stop pulling when the tension in the string has reached the adjusted tension. When the measuring system works accurately enough it keeps the tension constant during the slow elongation of the string.

NO ACCURACY WITHOUT “CONSTANT PULL ACTION”

A string that is tensioned needs time to elongate. A string that stretches more needs more time (up to 10 seconds) than a string with less elongation. A “constant pull” tension unit keeps the tension CONSTANT during the elongation of the string.The figure in the top right column shows three graphs, two without and one with constant pull action (Stringway MS 200)

“CONSTANT PULL” ACTION

Graph 1 : The string is tensioned fast to 30 kg., the actual tension drops to 23.1 kg.

Graph 2 : The string is tensioned slowly to 30 kg. and the tension drops “only” to 25.5

Graph 3 : The constant pull action of the Stringway MS 200 keeps the tension during the slow elongation of the string

Conclusions : Without “constant pull” action tension loss can be up to 7 kg. A stringer who strings quicker strings “softer”.