Whats the difference between an “instant off” and a “constant pull” machine?
A string that is pulled to a reference tension such as 60 lb. and is then clamped will immediately start to lose tension as it stretches. Instant off machines pull the string to the reference tension and then immediately stop pulling. Constant pull machines pull the string to the reference tension and then continue pulling at that tension until the string is clamped and the tensioner is disengaged. Because constant pull machine “take-up the slack” in the string for a longer period of time than instant off machines, they usually yield string jobs that are about 10% higher in tension than instant off machine. This is not a trivial difference and good professional stringers will usually ask their customers about the type of machine that was used for their previous string job. The main type of instant off machines are those that employ a spring and brake tensioning mechanism (that’s because tensioning stops and the brake is engaged the moment the reference tension is reached). Electric mac
