Hi, Recently I strung my racket using a drop weight machine. I strung the mains at 24lbs and the crosses at 26lbs. The job was good. My friend strung another racket using a manual crank machine at 27ilbs crosses and 27lbs main. This is just his method. Both strung one piece design and in the exact same way as he taught me. What was strange was that when tapping the string bed on each racket once strung, my racket sounded MORE high pitch than his. which i guess means that it is a higher tension. So my question is this. If i strung mine at 24x26 and he did his at 27x27 should his be higher tension?! Or is it because i did my crosses 2lbs more that it will make mine higher overall? Im confused as to how this works.... Either that or one of our machines is not calibrated well, and im pritty sure mine is calibrated fine.
1) Drop weight are constant pull. So the string tension holds better. 2) Crank machine usually use break/lockout when it reach the tension. The string will loose start loose tension once it is locked. 3) Drop weight machine only need to be calibrated on initial use. However, crank machine need to be calibrated every 3 mo to 1 yr depend on how often you string. So I am guessing his machine is out of spec. 4) Are both racquets same make and model?
The racquet with bigger frame should have lower pitch given the same tension. Also, are both strings the same too?
Erm you got me again Sheart! One was bg80 and the other was Kason P75....I guess I can see where your going, i didnt think of these variables! I thought a good way to measure tension was to listen to the pitch the strings produced when tapping them with an object such as another racket...it seems this test isnt quite as accurate as i thought in terms of which is a higher tension than another?
Well, it is (accurate enough), if everything else is kept the same. As silentheart says, there are just too many variables here to make the tapping method accurate. Even when everything is the same but tension, tapping doesn't tell you a great deal. Why not hit with both rackets and see how they feel? However, due to all of the different things you've changed, even this might not help a great deal.
This is a little out of this topic. We had a discussion before on this subject. The best way to do this test is to have a tuned piano or electric keyboard. Once you string a racquet, tab the string and match up the pitch/key. Then you can see the pitch/key change over the time to get a good estimate of tension drop. However, what if you are tone deaf? well we got a problem... Anyway, back to the subject. Yes, the pitch from tabbing sting is a good indicator of string bed tightness. If you have 2 different racquets and the pitch is about the same, they should play similar given the shaft has about the same stiffness. That is a lot of if... Also, thicker string has lower pitch. Enough of it. Good luck!
Whilst the pitch test is pretty crude the variables can change the pitch significantly. I think the biggest difference however is likely to be the machine. I completely agree with SH because when you use a drop weight you can prestretch the string by pushing down lightly on the tensioned string then when you let go the weight will drop further to take up the tension you have "stretched" out of the string. or SH tells you how he does this is this thread (post #6) http://www.badmintoncentral.com/forums/showthread.php?t=27443&highlight=pre+tension Personally I think you should prestretch when using a drop weight if you want an exact tension, but as long as you know how tight you want your strings then you can simply tension higher than you need then the prestretch will be taken out during stringing. The important thing is that you understand your machine or your stringer to get the right feel. I find that if you say 25 pounds to four different stringers with the same string and racket the result you get will be different in each case. Finally Neil Nicholls mentioned in one thread he read somewhere on the net that prestretching speeded up the creep in the string once strung. When posting on the subject later though he couldn't find the page where he read it.
Besides string type, head frame shape and machine, workmanship and clamping skills will also contribute to tension loss. Experienced stringer with better clamps (fixed vs. flying) usually get less tension loss than others. Of course, constant pulling machine can make up most of the loss in the next pull, if the stringer has his/her effective way to do so.
