baddy67, I believe your stringing machine is a hold-down system with two N/S screw-down clamps and two lateral side supports on each side. This system should give you a better stringing job than the other suspension system, provided you take certain precautions. To start off, you should place the racket flush with the two N/S mounting grooves and clamp clamp firmly. Next ensure that the two lower lateral supports, one on each side, are placed no lower than grommets #12 at the throat end, preferably between grommets #12 and #13. This will minimize any distortion of the frame when stringing the mains because any spot lower than grommets #12 at the throat end will not stop any 'rounding' distortion of the frame when doing the mains. The frame above the bottom grommets #12 are more easily distorted or bent, and placing the side supports here will strengthen it and prevent any 'rounding'. Placing the lower lateral supports higher will also benefit the crosses which will follow. To ensure a form of QC control, you can measure the length of the racket from racket head to butt end, without any strings and before stringing, and then check with a tape its length at every 3rd cross string as you start stringing the crosses. The first half of the crosses should have about 10% higher tension than the mains. As you reach the middle of the crosses the tape should be within the length of the original unstrung racket or about 1mm to 2 mm short but never longer. If it is much shorter at the mid-cross point then you may have to increase the remaining cross tension by say 1lb to 3lbs. Don't worry, the frame will not crack provided the lower lateral supports on either side are placed above grommets #12. The above will virtually give you a 100% perfect stringing job, with zero frame distortion.
Pre-stretching mains and not the crosses will result in almost the same reference tension. Most electric CP machines have a tendency to over shoot the reference tension. I was told the Yonex ES5Pro over shoots by +0.2, while other machines, even the Babolat Sensor and Star 5, tend to over shoot the reference tension by as much as +8 over reference tension. Theses tensions were measured on a Japanese Shimpo Precision Force gauge. This is WITHOUT Pre-stretch enabled. With Pre-Stretch enabled it will hold the "pre-stretch" tension longer before settling back down to the set tension.
i have tried making the 6 points firm. and north and south point r definitely not loose. the round part of the racket is happening at the bottom end of the racket. like a egg shape almost. SERIOUSLY! why is this happening =[. even tension at 22lbs still doesnt come out properly....
thanks taneepak, i will try placing the racket properly at grommets 12 and 13. hope this work outs. i am going to start another post asking if anyone has the victor machine and what is the way they mounted it. thanks though will let u know how it goes.
TANEEPAK, i have done what u said. it did help. but still..the racket is a bit in a egg shape =[. why...
What is the difference in racket length between the 'before' and 'after' stringing? Did you increase the cross tension by 10% over the mains? This is important for the first top half of the crosses.
At the risk of impersonating a seasoned stringer.... may I ask if you double pull your crosses? -- especially the bottom ones if you are stringing top-down and getting an egg shape. It might not be a major factor, but when I get to the lower half of the crosses I pull verrryy slowly and pull twice. Doing that (as well as doing what taneepak says with the supports) really helped me with the shape of my rackets and quality of the stringbed. Best of luck.
Same here. I usually pull the bottom half of the crosses (especially the ones with shared grommets) twice or more or simply single-pull but high the tension.
Make sure the 6points are not too tight, otherwise it should change the frame shape before stringing. If you keeping get an egg shape, maybe you should try to add 3lbs at the bottom, and add 2lbs in the middle and the top. I always get an egg using 2 knots way, but no problem with 4knots.
After broken 4 rackets same at 9 clock when stringing cross from head or bottom, I can say starting cross from middle will definitely protect the racket from high pressure. The negative is it will take longer time on stringing.
Just for the information of all those who fancy trying it, starting the crosses from the middle is impossible if you only have two fixed clamps - you'll need at least two fly clamps (and four would be safer) or your two fixed clamps and a decent starting clamp. I'd try decreasing the mains tension first, though - it's a lot easier - and make certain there's no play in the 12/6 support.
+1 I agree with Mark A. It's impossible to do a 50/50 cross with two fixed clamps, unless you have a fly clamp. The one exception is if the machine is a glide bar, like a Prince Neos.
Another +1 agree with Mark A This was the first time I've strung a racket cross from the middle I saw less frame distortion while stringing compared to top down and bottom up Doing it this way took longer but a few fellow member here said the playability is better Time to put the racket to the test
It's right, "as much as +8.0", which is a general term. It does not happen all the time, and varies from machine to machine. I've seen my Sensor and Wise 2086 got as much as +2.0 over, without pre-stretch enabled. These are over shoot readings, and not necessarily true pre-stretch. Most of the time Kevlar (Aramid) is used, but on some machines it "throws off" the sensors in the machine. These were all independent tests by an ATP stringer that used or owned the various machines. I beleive the USRSA did a similar test, but I can't seem to find the article.
It's good to find out all these reading for the machine, especially yours! Knowing them will indeed help your stringing ... a lot So one possible reason the guy who started this thread probably 'clamp' the string too fast before the pulling is over Or his machine probably got a lot more +?
My Appologies. I know I kinda hi-jacked or de-railed this thread, but I was trying to clarify what Double Pull meant, then led to pre-stretch some how. Rounding and slight deformation is pretty normal, it will usually even itself out as the strings settle. I don't think too much of it. It's not a big thing.
