Drop Weight yielding a really high tension

[shroyer@mc.edu]

so i have an AG 602 drop weight stringer. its nearly identical to a gamma progression 602 with flying clamps. my problem is that i seem to get tensions that are way too high. when i string around 55-60lbs it is accurate and feels the same as any other string job. however when i string at 50 or 52lbs there is barely any difference. a racquet done on a different machine is much looser. any ideas why this could be happening?

[Irvin]

Have you tried checking the tension?

[rich s]

what size head is the frame (mid, mp, os)?
what is the string pattern (16x19, 18x20)?

[shroyer@mc.edu]

yeah i checked the tension. ill set it to 50 and it would come out to something like 55ish. yet when i set it to around 60 it seems accurate. also its a wilson six one tour 90 inch frame 16x19

[Irvin]

Did you check to see what tension the tensioner is pulling? Sounds like you are talking about the racket tension.

[shroyer@mc.edu]

is there a difference between racket tension and the tension that the tensioner pulls?

[Irvin]

Originally Posted by shroyer@mc.edu

is there a difference between racket tension and the tension that the tensioner pulls?

Yes there is.

[shroyer@mc.edu]

oh is there somewhere i can find out about that? or is it something simple you can explain to me

[Irvin]

When a string has tension pulled it stretches. When clamping there is usually some tension lost because of drawback, friction, poor clamping, clamps too loose that slip etc. this results in a string bed tension lower than the strung tension.

Sometimes when using fixed clamps there is some play in the clamps and some stringers like to pre-load the clamps by pushing or pulling on them. This action can actually increase tension in the racket. Here is an example where you can see what I mean.

http://www.youtube.com/watch?v=x9FycyMXFWc

When you tension a string you stretch it. If you have a constant pull (drop weight is constant pull) the longer you pull the more you stretch. The longer you stretch the higher the tension in the racket although the tension pulled never changed.

So back to my original question have you checked the pulling tension of your stringer?

[Irvin]

And if you are testing the tension in a strung racket the size of the head, string, pattern, vibration dampening devices, among other things may make the tension appear to be non linear. There is not just one way to test tension in a strung racket. You usually have to include all those variables in order to get accurate readings.

[shroyer@mc.edu]

oh i see. no i have not tested the tension of my stringer yet. im looking to see if someone has a calibrator i can borrow around campus. thanks that video helped i think i might just be letting the weight sit for too long as well

[Irvin]

That is a good way to get a stiff stringbed. All the time you spend getting the bar level and moving the clamp the string is continually being stretched. One reason it is hard for someone new to get a consistent string bed from racket to racket. But with time you will be fine.