Hello guys,

I currently have quite a much of racket breakage at 3 or 9 o'clock while stringing at tension >13kg.

I didn't happen much with my old customised pro's pro but since i switched to the stringmaster 3700 (with head 2086 engine) it happen quite often...

From what i can see, side supports seem too far from each other but i can't get them closer.

Do you guy's have a solution ?
I'm quite desperate actually...

Couple of things:

• Ideally your side support should be closer to the middle of the racket, but it seems your towers cant get closer together because the 12/6 supports are maxing out?
• Are you sure you have the right pressure on all the mounts? Saitenkiller (s_mair) has a video on it on YouTube
• Are you pulling the last two mains on one side separately or do you do a double pull? Yonex recommends a double pull to prevent breaking at the moment (as in: don't pull B12/A16 at the top, but pull the last B10 at the bottom and let that pull B12)

Here is my mounting attached. I've strung 13-14.5 kg with this many times.

Thanks for your answer

Yeah i don't have much margin on the 12/6 support, maybe 1cm.
I'll try to go as close as possible

I don't double pull at the end of the main, i pull on A16 and on B10.
But i'll try to double pull from now

Hopefully a silly question, but donyou alternate each side when pulling mains? Or do you do all of one side, then the other? Or batches of a few at a time?

Good luck! I mount mine similar spacing to you a did a recent 32lb, no issue.

Yeah of course i alternate each side.
I don't see any racket which can stand that kind of treatment

I've strung some yonex rackets at 14kg and no issue but recently broke one aeronaut 9000 and a thruster TTY at 13kg. These rackets are not supposed to be weak so the problem should come from the setup.
A good friend of mine is from yonex stringing team and he was in the olympic.
He told me the same as thyrif about the spacing between the side sipports and the double pull for the last mains.

I've tried the maximum of the machine and manage to gain about 1.5cm for the spacing.
I'll see if its enough or else, i'll have to switch to another machine ...

To me that sounds like the racket is not properly supported.

1. Are you sure that the main supports are tightened properly? It may feel the same as before but not be as tight as you had them with your old machine.
2. Do you re-tighten the 6 o'clock support after tensioning the first two mains? It may be a way to make sure they're tightened sufficiently.
3. Just to make sure: The load spreader at 12 o'clock is an H-piece for badminton?

Moving your side supports further towards 3 and 9 o'clock may help but it will introduce more stress in the parts between the side and main supports. At 1:30, 4:30, 7:30 and 10:30, roughly.

1 : Yes it's well tightened, i first, go to contact on the main, thighten the side support and add a bit of constrain on them.
Than i pull the first 2 mains and re tighten the main support (turn the lock until it gets hard without adding lot more strengh on it)

3 : the load spreader is the official one from Yonex, it cost 20€ alone for this one. It's the same used by official Yonex strigner at Olympic

It seems weel fixed for me as i put a bit of strengh on it after contact. The racket doesn't seem to move while pulling.

a lot of the most reasonable things were already mentioned. Let's look at the phyics here. You indeed have the side supports quite far apart which of course reduces the amount of support the side supports can actually provide to the frame at 3/9 o'clock.

To the contrary, if you have the side supports that far apart and tighten them a lot, that could even add extra stress at exactly the 3/9 o'clock spot. Just imagine the frame being compressed by the mains, it adds some load to the side support pieces which kind of deflect it towards the center of the frame instead of taking the load away. That's at least what I can imagine happening there just looking at it and thinking it through - no measurement involved or anything.

So here's what I would do:
1) get the side supports as close together as the machine allows
2) make sure to have the side supports firm, but not overtighten them
3) definitely do a double pull on the last two mains

Good thing is that the issue only arises with very high tensions. However this shows that the frames see a lot of stress peaks there and that it would clearly be beneficial to optimise that, also for lower tension jobs.

Good luck!

i have the TK TTY mounted on a VICTOR machine for your reference. Seems like your machine mounting is indeed too far apart.

Does it happen while you're pulling the last mains or while installing the crosses?

What I've noticed: it seems that you tie off on the wrong grommets. Mains should be tied on B8 and crosses on B6. It also looks like the left knot on you picture is slipped in the grommet.
IF the breakage happens while installing the crosses, that could be the problem.

It could also be that the string slips on one side through the clamp. You can check that easily with a flying clamp. Just clamp the flying clamp directly behind the fixed clamp.

If there is a space after releasing the tension, the string slips through the fixed clamp. Sometimes it is not that much and you cannot see or feel it without this method. Or there is very little at first and then it slips through more.

Thanks for your remarks, I've tried to string the same rackets and tension with your advices and it didn't break so it seems ok from now
I regret so much buying a 3700 pro instead of the deluxe. There was only 100€ difference and from the photos, i didn't noticed the issue.

I will switch to the deluxe (and get the Ennox engine at the same time) when available on tennisman website

Yeah, even by going as far as allowed by my machine, i'm a bit wider than your setup. I'll wait to switch to a stringmaster deluxe when available.

I understand your message but i think you got it wrong. The breakage is on the racket and not the strings

I check quite often if my strings slip through the clamp and normally it don't (i do it by looking the inscriptions on the string when release the pulling)

That’s good to hear, I hope it stays that way.

Yeah, looks like the 3700 is more catered towards tennis stringers but there was no chance to see this from the pictures. But at least it’s the perfect excuse to treat yourself with the Ennoxx too.

Could you post a pic that shows how close you could manage to get the supports together by any chance? Just as a reference.

Not even that, the 3700 was a Badminton only machine ...

I'll post a updated picture tomorrow

I thought the 3700 pro was a badminton specific machine and it looks like the side supports would be a similar distance to like the current Li Ning / Victor machines