Premium Stringer 8700 Electro string slippage from the gripper

Lukhas

Legend
Hello,

My tennis club owns a Premium Stringer 8700 Electro. The gripper physically looks more like the one you find on the 9200, which has an open design, instead of the "original" one that has a closed design. I consistently get string slippage with slick strings like monofilaments and sometimes even gut. It grips fine when I string synthetic gut or multi. But when you combine the fact that the racquet mount sits pretty far from the motor, the fairly unconventional tensioning system with a pulley/string guide, and slippery strings, I'm left with fairly little string when I'm on the last mains or crosses and the strings just keep slipping away from the gripper. Is there anything I can do? Aside from buying my own machine, which I can't really afford to at the moment both financially and in terms of storage space.

This is what the vanilla gripper generally looks like when I look it up online. It seems to sport some kind of cover.



This is the one on the machine at my club: it has an opening on the side. Disregard the fact that the picture comes from a different stringing machine. The top portion, the "jaw" seems spring loaded: I tried to use it to bite the string, but I have not been lucky, even when trying not to use the string guide/pulley (in which case the string just slips out of the jaw).


 
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Lukhas

Legend
When was the last time the gripper jaws were cleaned? I suspect you have residue from prior string jobs inside the jaws.
Good question. Probably not recently if ever. I haven't dared to dismount it since it's not my machine. I won't be able to look it up before a while, the club house is closed at the moment. I think I'm the only one voicing the issue, so I had figured that I might be doing it wrong... even though there's a label on top of the machine showing you how to use it.
 
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esgee48

G.O.A.T.
Soak a shoelace in 91% alcohol and run it between the jaws. Do it several times between periods of drying and that will elimenate that as a possible issue. HTH.
 

Lukhas

Legend
Soak a shoelace in 91% alcohol and run it between the jaws. Do it several times between periods of drying and that will elimenate that as a possible issue. HTH.
I got around doing it today. It was objectively better and I had less slippage. The gripper mechanism still sucks though, and I still had the string slipping through the slit at times. I think the string slipping through the slit also has to do with the gripper seemingly not being the original one, which does not have a slit.
 

Irvin

Talk Tennis Guru
@Lukhas Are you wrapping the string completely around the gripper assembly before placing it between the 2 jaws? I would take the drum off and clean it will with 91% alcohol and a toothbrush. Make sure when you replace the top (spring loaded) section you do not over tighten the screw or it will not move freely.
 

LOBALOT

Hall of Fame
In addition to cleaning I think the other thing that would help is to either cut more string from a reel so you can get to the gripper to adequately wrap it and/or if using packets buy a starting clamp and bridge. To bridge I would use string that typically does not slip for you (For example I have Prince Topspin 15L in mine).
 

Lukhas

Legend
Thanks for all the replies. I ended up taking off the top portion of the jaw to scrub it. I ended up with string residue in the jaw when I was done stringing. I still have to be careful about holding the end of the string while I tension it, but at least stringing co-poly is only unpleasant instead of being impossible. It's still not the kind of mechanism I would recommend, it's quite the waste of time to wrap the string around ta post then wrapping it around the drum and inside the jaw, AND then make sure the string is being pulled correctly.

@Lukhas Are you wrapping the string completely around the gripper assembly before placing it between the 2 jaws?
Here's a picture of the instructions on the machine while I was cleaning the jaw.



In addition to cleaning I think the other thing that would help is to either cut more string from a reel so you can get to the gripper to adequately wrap it and/or if using packets buy a starting clamp and bridge. To bridge I would use string that typically does not slip for you (For example I have Prince Topspin 15L in mine).
I don't have such a string, but ironically I had to use my Pro's Pro starting clamp to finish the mains on a Yonex Ezone 100. While I was stringing my racquet, I was asked to string someone else's frame with a set of Babolat Hurricane Feel and accepted. While their racquet was strung one piece, I preferred to follow Yonex's instructions to string two pieces. I cut the set in half, and there was not enough string to reach the tensioner at all when finishing the mains. I used leftovers from my own string job to tension the mains; I used a piece of Yonex Poly Tour Pro I put in the mains rather than the Babolat Origin I have in the crosses.
 
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Irvin

Talk Tennis Guru
Here's a picture of the instructions on the machine while I was cleaning the jaw.
Bad design IMO. The string should not go around that nylon roller, it should go directly over the top of the gripper, around the bottom, and finish through the slot. As you apply tension the string pulls the top of the drum that’s spring loaded down to clamp the string. But dependent on the design that may not be possible.
 

Irvin

Talk Tennis Guru
@lukas Looking at the picture a second time it looks like that nylon roller is on a pin that slides in a slot. If the pin slid toward the racket as tension the string would have better leverage to compress the jaws and grip better. Is then pint / nylon roller binding up so it does not move?
 

Irvin

Talk Tennis Guru
@lukas in this video starting at around 0:45 I should how the rotary gripper on my Gamma machine works to give you an idea of how the jaws of a rotary gripper work.
 

Lukhas

Legend
@lukas Looking at the picture a second time it looks like that nylon roller is on a pin that slides in a slot. If the pin slid toward the racket as tension the string would have better leverage to compress the jaws and grip better. Is then pint / nylon roller binding up so it does not move?
The pin does move towards the racquet as you tension it, and I suspects this is what tells the machine that the desired tension has been reached.
@lukas in this video starting at around 0:45 I should how the rotary gripper on my Gamma machine works to give you an idea of how the jaws of a rotary gripper work.
The top portion of the gripper on the machine at my club does a pretty poor job at pressing down on the string consistently. That being said, I was so focused on my job that it's possible I remember poorly. Although when I think about it and as shown on the picture with the instructions, the top portion of the gripper lays at an angle instead of being straight; the outer rim is very slick, so it makes it easy for the string to slip out of position. I didn't have that issue with the machine at my previous club which was a Gamma Progression ELs (or very similar): the jaws of the rotary gripper was going a very good job at grabbing the string. I end up thinking that this convoluted system with that gripper bar/pulley is unnecessary complicated for little benefit on top of wasting sometimes precious string length.

Also, my username is spelled with an useless "H", so you've been pinging someone else who has a similarly written name. :whistle:
 

Irvin

Talk Tennis Guru
The pin does move towards the racquet as you tension it, and I suspects this is what tells the machine that the desired tension has been reached.
I doubt that, but it’s possible. If the nylon roller applies tension to hold the string and shuts off the motor when tension is reached it won’t grip well until final tension is reached.
Also, my username is spelled with an useless "H", so you've been pinging someone else who has a similarly written name.
@Lukhas I used username suggestions and your login is similar to Lukas which popped up first. Sorry about that. @lukas sorry for tagging you too.
 
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