So, I've had this problem for a while now and so far I've not had any frames break, btu it's starting to worry me. I string my HX800's and sometimes a JS10 around 30-31lbs, my set-up is a premium stringer with one-knox-adjustement and Michal's supports I do one piece bottum up where the bottom 2 strings are the short side. When I get to the last couple of crosses I notice my side supports are getting more and more loose and the frame starts to move around the supports (you can hear the paint squeek over the supports, which is kind of disconcerting). I string 13,5kg main and 14,0 cross (29.7x30.8), could it be my ratio? am I tightenting the supports to little or too much? At the moment I daren't use the 10% pre-stretch at my current tension. Can anybody help with some pointers?
Best thing to do is measure the racket with and without strings to see what's happening. If the racket is longer and the head is narrower then I'd drop the cross tension a bit.
I agree with @druss. 1) adjust your cross tension slightly lower the next time Or you can also 2) gently tighten any supports that loosen as you string the crosses. Option 1: is probably better as it is an indicator that your cross tension may be slightly too high. Where option 1 doesn't really apply is if you us the old style chudek supports with the rubber tubing on the supports. They have some give on it so i can't tighten my supports as much. As i get halfway through the crosses i check my supports to make sure they aren't loose and tighten them if they are. I do know the plastic on the new style chudeks aren't as grippy as the old ones with the tubing. Hope this helps.
Could it be that upper side support is a bit high? I usually like to move it just below the first shared grommet. The frame is very weak where you have it and prone to move more...
I string my JS10's on regular base with a PS3600 at same tension and ratio. I use the tubing on my Chudek's instead of the inlays. My Premium Stringer is different to yours. I experienced also movement with the inlays, but nothing with the tubing. I also done square on the machine, which don't come out with ease and a slightly bit round so 0.5kg/1lbs+ on crosses sounds reasonable. I also have sometimes issues that the supports become a tiny bit loose and need to tighten 1mm gently if I reach the 10-12th cross. Never the less my rackets come out shaped like an unstrung frame at same length so I think that it's not the ratio. I mount my racket slightly different to your set-up. IMO you should just deal with it. Guys who uses a machine which costs less than two Toyo clamps can't await a solid machine like an ES5 Pro.
I second the above - try 31/31 or 30/30 and see if that helps; machines always have a "preference" for cross differential, if any. Also, check your 6 o'clock support after you've pulled your first two mains - there may be some slack there, maybe 2-3 mm. (Lastly, I think your lower side supports could be a couple of holes higher - I have mine right where the racket is widest)
That was mostly for safety, if you want to call it that. I saw no difference in terms of shoulder support separation, but I did start to use a Yonex H-piece - much less deformation than the "fingered" versions. There should always be some pressure on the side supports when you take the frame out of the machine; if there was no pressure, what are they there for? Equal pressure applied to all contact points is the ideal.
I agree. With square at 30 and above I struggled to get the knob loose. With 1lbs/0.5kg, they are firm and tight, but also possible to get the racket out. I remember the period when I did 30/30 and need a towel to get the bottom side support loose with coughing.
update from my end, I strung two more frames, which turned out fine. The main difference: I think I over-tightened my side supports previously (more than finger tight),
