I was referring to the following post regarding using cross string to temporarily hold the sides while the mains are being strung: I used 20 lbs on the mains and 22 lbs on the crosses (60 lbs and 65 lbs respectively on the scale on the M140).
NOT Acceptable Josico, I am amazed to read this. I would have bet $100 USD that a Yonex VT80 could NOT be distorted to almost a circle using only 20x22 lbs., even on a 2 pt. machine. This is certainly NOT acceptable. Chirs-ccc mistakenly thought you were talking about using lower tensions on crosses than mains. You were actually asking whether you should be using the temporary cross string trick even with the low overall 20x22 tension. I would have guessed that you would not have to do that, but apparently you WILL need to do that. If tricks are needed on high end strong rackets at low tensions to get acceptable results on a 2 pt. machine, then I don't see how anyone can recommend them. Seems like a lot of trouble for very mild conditions. I guess the good news is that the tricks will work, but you will apparently need to do them in ALL cases.
The amount of racket distortion you describe (almost a circle) for 20x22 lbs. of tension makes me wonder whether you have a major miscalibration going on. Did you test the actual tension pull against your scale settings? I think you may be pulling way more than 22 lbs. Another outside possibility for so much racket distortion at low tensions would be if you had a cheap fake copy of a Yonex VT80. But if you paid a normal price for your racket that is not likely.
The two points you raised are the reason why I am wondering about what I am doing wrong and where I can correct my mistakes. 1. I tested the tension with two different scales, one from a local store for weighing fish and the other is the Eagnas tension calibrator (http://www.eagnas.com/store/product_info.php?products_id=67). Both read that the tensions are correct. I also purchased racquetTune (http://www.appmaker.se/?m=4&s=0) and the tension readings show 19.8 lbs - which is close and definitely not at a high tension. 2. The racquets were purchased from Shuttle-house.com (http://shuttle-house.com/new-cgi/item_cart.php?mk=YONEX&hid=VT80). The frame returned back to normal after the strings were cut.
You have definitely covered the calibration issue in a comprehensive fashion and proven that you are not pulling more than you wanted. I hope one of the 2 pt. machine masters comments soon on this. Maybe this is common for such machines even at low tensions unless special measures are taken. Will be interested to hear what they have to say about your situation.
Thanks for your comments, one thing I will add for everyone to know is that the first time I strung the racquet (when it looked the most circular), I didn't tighten the posts to the frame of the racket. I had left some space between the black portion of the fastener (centered on the leather surface). I noticed that when I finished the string job, the racquet was tight to the black metallic surface. For reference: Current setup - no space between black metallic surface of fasteners and racquet head: Problematic setup - space between black metallic surface of fasteners and racquet head: Hopefully the masters will be able to spot something I did wrong or am still doing wrong?
Where are all the 2 Pt. Machine Masters? Guys, when comments were made questioning the value of 2 pt. stringing machines, there was no shortage of people speaking up for them. But now that Josico has presented his case where with numerous attempts in good faith and with great care, he keeps having his Yonex VT 80 look like a pumpkin at the low tension of 20x22 lbs. there is not a peep from anyone. Can someone experienced with 2 pt. machines advise him about this problem? Afterall, he is using the fabled Klippermate M140 machine which is known to be a quality 2 pt. machine. At these low tensions of 20x22, does he really need to use temporary cross strings or other tricks to avoid racket deformation? Aren't you supposed to be able to use the machine in a straight forward fashion with no tricks when using low tension on a quality racket?
OK, I see one potential problem. in first picture, please take the racquet off the setup. Then rock the posts back and forward 2 or 3 time. Then push both posts toward the center of the turn table. Then put the racquet back on the mount. You will see there is about 3mm~5mm space just like picture #2. What does that mean? That mean he need to mount the racquet then move one of the post out ~3mm then tighten the wing nuts again. Good luck.
OK, so I got some time yesterday and tried SH's suggestion. I didn't seem to help much as the posts did not move much even with tapping or rocking them. This may be due to the fact that the machine is still new (I just got it in last Friday). I'll keep this in mind for later though. That aside, I did try the cross stringing first trick. I strung four cross strings with 20 lbs of tension. I noticed that the racquet became narrow and long (I compared it with an unstrung racquet to verify this to be true). As I continued to string the mains, I released the cross strings as I reached B9 as the clamps were getting in the way. At this point I noticed the racquet was no longer elongated and verified with the unstrung racquet again. Everything was well! Finished stringing the rest of the racquet and everything looks to be good. So I guess it is good to do the cross string trick regardless? Adds a couple of minutes to the string job though.
Congratulations! Very glad to hear that you got your racquet strung and maintained its proper shape. Its kind of funny how you have to first squeeze it narrow so as to compensate for the compressive effects of the mains. Since this cross stringing trick is not mentioned in the standard instructions for the machine and yet it seems to be required to maintain racquet shape even at low tensions, it makes me think that a lot of beginners using 2 pt. machines just accept racquet deformation as normal. Kudos to you for not lowering your standards and working hard to find a good solution!
thanks everyone for the compliments and support, now i shall start another thread so i don't hijack this any further
If you do end up deciding to purchase a 2 point system, check out atssports.com I purchased a Gamma Progression 200 and it comes with all tools etc and free shipping to USA. You will need better fly clamps and I bought those from MBS cause they are cheaper and better And I have strung racquets at 26/28 with no issues with headshape deforming. Just have to make sure you mount everything correctly and tighten all the bolts... I messed up a Nanospeed 100 when I was practicing.
If the racket came out "round", that means the difference between cross tension (higher) and main tension (lower) is too small. Usually, that means either you did not mount the racket correctly, which left too much gap (like pic#2), or, the posts were not secured, which will lead to a setup like pic#2 when tension. The way I do it, is to loose up 1 post, and mount the racket, to make sure the mounting piece is against the inner frame. Then, use 1 hand to push against the loose post (not too much force, but surely start to feel a bit resistent due to the frame), while use a piler to tight the screw.
