Constant pull stringing machines

rich s

Hall of Fame
A drop weight or electronically controlled machine provide constant tension to string when stringing.

a crank machine locks out at a preselected tension. The string then begins to lose tension while the tension head is locked.

the net result is a string bed that is about 5-10 % lower in tension than a constant pull string job.

Craig Sheppard

Hall of Fame
Ohhhh ok thanks a lot Rich, I thought there was some piece of technology I was unaware of on higher-end machines. I thought about my drop weight machine and didn't think there could be any more constant of a pull than with it pulling, well, constantly... So that's why 60 on my machine is different than 60 on a hand crank. Thanks a lot...


Jerry Seinfeld

With constant pull, the machine will continue to pull tension as the string elongates until it is clamped off. This makes it VERY important that the stringer remains as consistent as possible from string to string and string job to string job with his/her method of pulling and clamping. If "String A" is pulled and clamped off in 5 seconds and "String B" (same length for illustration) is pulled and not clamped for 20 seconds because the stringer stopped to answer a customer's question, then the actual tension will vary. Again, stringers using contant pull machines need to be EXTREMELY consistent or their end results, stringbed stiffness, will indeed vary. With a lock-out machine, this isn't an issue, because the string is always locked out at the same tension.

Gaines Hillix

Hall of Fame
Jerry, I believe this is also an issue with a lock out machine. When a string is being held by the tension head on a lock out machine, but is not clamped off it will experience a higher rate of creep or tension loss until it is clamped off. It will still experience some creep even after it's clamped off, but it's more pronounced on a longer string, which is in effect what one has when the string is only being held by the tension head. Consistency is important on these machines too, IMO.

David Pavlich


Gaines has it right. You have to be consistant whether you're using a Klipper or a Sensor. Without it, the string job will be sub standard.