Newbee Questions: marks on frame from machine, strange slipping & odd string break

[TopspinDoctor]

I have just started stringing on a simple Gamma progression 220 machine and have a few questions that puzzles me:

1) The machine leave small marks on the inside of the frame, where the threaded mounting bolt meets the frame. Is this normal? I think it is more cosmetic, than worrying... I am not mounting the racket pressuring the bars outside towards the frame, but when the mains are tensioned, I guess this squeeze the frame against the mounting bars. But I guess leaving marks then either I am doing something wrong, or the machine is designed poorly?

2) Trying to avoid a double pull when having only 2 flying clamps, I use the very nice method from Yulitle:

My challenge here is that the flying clamp positioned *outside* the frame as instructed, SLIPS when this clamp is the only one holding pressure. I do insert a piece of string in the empty jaw, so the clamp should clamp like when it is mounted inside the frame the usual way. How come the flying clamp slips, but only slips in this position/used this way? I adjust my clamps so I need a little/moderate pressure to close the clamp. The clamps never slips when mounted the usual way inside the frame....

3) In search for a nice string with a little better durability than Wilson Sensation, I tried the Technifiber, syn gut. During warm up the other day first time using the racket, the string broke in the very top. I have never had a string break here before. Have I done something wrong in the stringing, that can cause this type of break? See photo link. I use 2 piece stringing and a rather normal 25/24 kg tensions.

WprostaffStringBrk.jpg

drive.google.com

My racket is a brand new Wilson Prostaff, so I would not suspect the racket/grommet.

Thank you very much for helping me out ;-)

 

[Irvin]

When you clamp the string outside the frame clamp the 1st and 2nd mains with a loop long enough to reach the tensioner gripper.

Your bottom cross is tied off inside the outer main. Sooner or later it will probably slip under that main. I’d use 8Tto tie off mains, and 6T for bottom cross.

 

[TopspinDoctor]

Thank you very much.

When you clamp the string outside the frame clamp the 1st and 2nd mains with a loop long enough to reach the tensioner gripper.

I am not sure if I understand your suggestion. When I clamp the string outside the frame it is this position of clamping that gives me trouble:

Only one string is clamped for keeping tension, I just use a crap piece of string for the other jaw, so the flying clamp gives the clamping pressure it normally does.

Your bottom cross is tied off inside the outer main. Sooner or later it will probably slip under that main. I’d use 8Tto tie off mains, and 6T for bottom cross.

I think I tie off using the position Wilson suggests (11T), but maybe the knot is wrongly made; please see this photo from the opposite side of the racket if it is OK, thanks?

 

[struggle]

11T does not appear correct, but i don't know which ProStaff this is.

Klippermate site doesn't indicate 11T for any of them.

T= top.....not throat (B = bottom....which is throat)

 

[TopspinDoctor]

OK, thanks a lot

 

[Irvin]

I think I tie off using the position Wilson suggests (11T), but maybe the knot is wrongly made; please see this photo from the opposite side of the racket if it is OK, thanks?

Who strung that racket? Looking at the photo in the OP you have 8H a shared hole instead of using 7H for top cross.

I know that Wilson instructions says to use 6T for mains and 11T for bottom cross. I’m saying I believe that is wrong.

 

[TopspinDoctor]

I strung the racket, just blame me . I just followed the instructions from Wilson to my best.

No opinion or input from the experienced stringers on the odd string break, or why the floating clamp slips, but only when used like described? That would be very much appreciated. Thank you.

 

[Irvin]

The machine leave small marks on the inside of the frame, where the threaded mounting bolt meets the frame.

There are some oval shaped pieces that are supposed to go down the post to hold the racket about 1/4” from the post to protect the racket.

No opinion or input from the experienced stringers on the odd string break, or why the floating clamp slips, but only when used like described? That would be very much appreciated. Thank you.

The break appears to have happens right at 12 o’clock as opposed to off center. If it was off center just a little it could have been shearing. That leaves 2 other possible. 1) it could be clamp damage but the string at the point where it broke is not held by the clamp. 2) it could be your string was twisted which made it kink when you double pulled the first 2 strings. I think it is impossible to ascertain from a picture why that particular string broke. The best you can hope for are ideas that could have caused the break.

 

[esgee48]

If you are marking the inside of your hoop with thread marks (from hold down post), put a scrap piece of leather or OG there to cover it. I suspect that your frame is moving because it did not tighten down the hold down mechanism enough.

You are using a ersatz starting pin and using a method 'pioneered' by KlipperMate. With floating clamps, both strings are pressed against the central block by the jaws. If there is slippage, one string is higher near the jaws then the other. Make sure you are as deep as you can go into the clamp. FWIW, some strings can tolerate slippage, others can't and can break later when under stress.

Include a picture of the hoop with the string break if this happens again. Also tell us what frame you are stringing. There are MANY PRO STAFFS out there in the wild.

 

[struggle]

I'll defer to Irving on this one.

 

[TopspinDoctor]

Thank you very much Irvin, much appreciated

There are some oval shaped pieces that are supposed to go down the post to hold the racket about 1/4” from the post to protect the racket.

I am using the oval pieces, but wondering why they are so narrow providing little solid support? The marks are not left on the side of the frame facing outwards, but located inside just between the two grommets. Threads from the "pole" cuts a bit into the frame, so to speak.

The break appears to have happens right at 12 o’clock as opposed to off center. If it was off center just a little it could have been shearing. That leaves 2 other possible. 1) it could be clamp damage but the string at the point where it broke is not held by the clamp. 2) it could be your string was twisted which made it kink when you double pulled the first 2 strings. I think it is impossible to ascertain from a picture why that particular string broke. The best you can hope for are ideas that could have caused the break.

Good ideas and suggestions, it could actually be clamp damage (too tight or the slip), as I did indeed clamp the string just outside the frame in order to follow the guide from YULitle (his racket start stringing reverse end compared compared to mine for the mains):

A kink could be produced by me, but I would expect this to be located further "down" the string as it is most likely the wrapping around the gripper, that can produce a kink when double wrapping/pulling, I would guess.

 

[TopspinDoctor]

If you are marking the inside of your hoop with thread marks (from hold down post), put a scrap piece of leather or OG there to cover it. I suspect that your frame is moving because it did not tighten down the hold down mechanism enough.

Good suggestions thanks, I will try to tighten the mounting knots more firmly next time and see if it makes a difference.

You are using a ersatz starting pin and using a method 'pioneered' by KlipperMate. With floating clamps, both strings are pressed against the central block by the jaws. If there is slippage, one string is higher near the jaws then the other. Make sure you are as deep as you can go into the clamp. FWIW, some strings can tolerate slippage, others can't and can break later when under stress.

Include a picture of the hoop with the string break if this happens again. Also tell us what frame you are stringing. There are MANY PRO STAFFS out there in the wild.

I am not sure what an "ersatz starting pin" is, but just used one of the two floating clamps that came with the Gamma. I will make sure both strings sits deep in the jaws, next time I try to use the clamp as a starting clamp

The racket is a Wilson Prostaff 97L, and I love it Thank you for helping me out

 

[esgee48]

The PS 97L skips 7,9 hoop and throat when installing mains. Tie mains at 8 throat. Crosses tie off at 5 hoop and 6 throat. First cross is 7 hoop.

KM uses a metal starting pin to start mains. You are using a very stiff string, which is why I call it an ersatz (fake) starting pin.

 

[Irvin]

I am using the oval pieces, but wondering why they are so narrow providing little solid support? The marks are not left on the side of the frame facing outwards, but located inside just between the two grommets. Threads from the "pole" cuts a bit into the frame, so to speak.

There are actually 2 pairs of different size spacer. You should be using the thickest side of which ever spacer that does not couch the grommet. If the throat is much thinner that the head of the racket you could use different spacers or sides in the head and throat. The racket is actually held by the rubber pads above and below the racket not by the post or the spacer. The host is simply used to compress the top and bottom pads to compress them on the racket. The slanted spacers are used to hold the threaded post away from the racket to prevent scratching. The racket and post could be coming in contact with each other mounting and dismounting the racket So be careful.

Good ideas and suggestions, it could actually be clamp damage (too tight or the slip), as I did indeed clamp the string just outside the frame in order to follow the guide from YULitle (his racket start stringing reverse end compared compared to mine for the mains):

That is quite possible since you had your break outside the frame between 1H and 2H. I never clamp a string outside the frame where it could be used to bend around a grommet or be used in a knot especially if it is at the feed of the racket. Miss hits occur more at the head than the throat. A spacer could be used at the head and placed between the clamp and frame to prevent this. That spacer should be at least 1” long. A 1/2” PVE/CPVC union may work perfect.

As for slipping, well with 2 clamps on the string when you applying tension I’m guessing that’s your problem. More likely you’re clamping the string too tight or applying too much tension for the composite clamps.

 

[TopspinDoctor]

The PS 97L skips 7,9 hoop and throat when installing mains. Tie mains at 8 throat. Crosses tie off at 5 hoop and 6 throat. First cross is 7 hoop.

Thank you. Strange Wilson recommends different tie off for mains:

KM uses a metal starting pin to start mains. You are using a very stiff string, which is why I call it an ersatz (fake) starting pin.

The string seems very soft to me, much softer than Wilson Sensation. Maybe there are different versions of the Technifiber syn gut? I have just received a proper starting clamp, so hopefully my challenges on slip for starting the mains without double pull is over ;-)

Thank you.

 

[TopspinDoctor]

There are actually 2 pairs of different size spacer. You should be using the thickest side of which ever spacer that does not couch the grommet. If the throat is much thinner that the head of the racket you could use different spacers or sides in the head and throat. The racket is actually held by the rubber pads above and below the racket not by the post or the spacer. The host is simply used to compress the top and bottom pads to compress them on the racket. The slanted spacers are used to hold the threaded post away from the racket to prevent scratching. The racket and post could be coming in contact with each other mounting and dismounting the racket So be careful.

Thank you so much, this is very helpful information This was not clear to me from the manual

That is quite possible since you had your break outside the frame between 1H and 2H. I never clamp a string outside the frame where it could be used to bend around a grommet or be used in a knot especially if it is at the feed of the racket. Miss hits occur more at the head than the throat. A spacer could be used at the head and placed between the clamp and frame to prevent this. That spacer should be at least 1” long. A 1/2” PVE/CPVC union may work perfect.

As for slipping, well with 2 clamps on the string when you applying tension I’m guessing that’s your problem. More likely you’re clamping the string too tight or applying too much tension for the composite clamps.

So when I make my debut using the new starting clamp, I guess I should still follow your advice on a spacer, right? And forgive me if it is a stupid question (English is not my native language): the spacer you suggest is just a hard plastic tube of some kind, right?

Thank you

 

[lwto]

Are your clamps broken?

 

[TopspinDoctor]

No, but I am a beginner starting with a Gamma machine that comes with only 2 flying clamps, and using them as starting clamp has been a challenge.

 

[Irvin]

So when I make my debut using the new starting clamp, I guess I should still follow your advice on a spacer, right? And forgive me if it is a stupid question (English is not my native language): the spacer you suggest is just a hard plastic tube of some kind, right?

If you’re using flying clamps yes I would use a spacer wide enough so the portion of the string clamped by the starting clamp ends up inside the frame. Also I would prefer to use the starting clamp at the bottom of the frame not the head.

I would put the starting clamp on the second main and tension the first main at the throat assuming your mains start at the throat. Then tension and clamp 3 mains on the other side before removing the starting clamp. If you mains start at the head as YUlittle‘s racket did I would place the starting clamp on the 1st main and tension the 1st main on the other side.

 

[struggle]

Get yourself a starting clamp.

 

[TopspinDoctor]

If you’re using flying clamps yes I would use a spacer wide enough so the portion of the string clamped by the starting clamp ends up inside the frame. Also I would prefer to use the starting clamp at the bottom of the frame not the head.

Thank you; and I assume your preference for throat position for the starting clamp is because mishits are less likely in this area...

I would put the starting clamp on the second main and tension the first main at the throat assuming your mains start at the throat. Then tension and clamp 3 mains on the other side before removing the starting clamp. If you mains start at the head as YUlittle‘s racket did I would place the starting clamp on the 1st main and tension the 1st main on the other side.

Got it, thanks

 

[TopspinDoctor]

Get yourself a starting clamp.

I just received one