# To use diablo or not?

Discussion in 'Stringing Techniques / Stringing Machines' started by bugeyed, Nov 9, 2012.

1. ### uk_skippyHall of Fame

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I'm using a Babolat Star 5. Do I need to answer your question??

A screen door could be useful on a submarine, on the inside. So it's a matter of perspective and interpretation

I never said that diabolo works (well), I merely highlighted that a machine with a rotational (read non-linear) tensionhead can have a diabolo.

2. ### IrvinG.O.A.T.

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I know on a Wise it is called a diablo and i believe it spins. I know on a Star 5 it is called a nosecone (or diabolo) and i believe it does not spin. Whether the little thing on the front of the tensioner spins around or not (no matter what it is called) makes all the difference in the world.

If that little knob spins it equalizes tension in the two sections of string connected to it. Whether you wrap the string around it 1 or 10 time does not matter. If The tension on the two sections of string is different the knob spins to equalize tension. On a lockout as the gripper assembly tilts up (rocks) the string section between the gripper and the knob get just a tiny bit shorter. If the knob did not spin then the tension between the knob and the gripper would be less than the tension from the racket to the knob. On a lockout should you use the knob? Yes the knob keeps the string going into the gripper at a specific and constant radius from the pivot point. As the radius gets longer it takes less tension from the string to rock the gripper up to lockout the crank.

If that little knob does not spin then the string sliding on the knob creates friction and the tension on one side of the knob may be different. If the tension is lower on the side with the gripper there is less pressure on the string. In this instance the knob only functions to protect the string from the crushing force of the gripper. If the stringer wraps the string around the knob more than once it will create more friction and even less stress from the crushing force of the gripper and will put more string under tension between the gripper and the racket.

3. ### bugeyedSemi-Pro

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Nice closing argument. I think we are all on the same page now. Finally!!!

Cheers,
kev

4. ### jim eHall of Fame

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No it does not.

Normally I can agree with you Irvin, but.....
I do not agree with that comment, as is not the only function as you say!

Like I said, it also allows the string to enter the linnear plates at the same angle with each pull, (that is another function with any racquet using the diablo) , and when stringing O Ports, the string is not at a severe angle to the end of those plates when pulling tension when using the brake, as the diablo eliminates that.This way, I can use the brake, pull at angles and string the racquet just like the manuf. pattern states and manuf. lists using the brake and not using an s hook, 50/50 or any other devise.
The diablo allows the string to be straight from the diablo to the plates holding the string.Otherwise the string at times could be at a sharp angle to the plates if pulling a sharp angled pull.So it is not just the crushing force of the gripper it protects, but also the angle it keeps the string at to the plates to protect as well.

So you see that is not the only thing it is functioning for as you said in above quote.

Last edited: Nov 10, 2012
5. ### struggleHall of Fame

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yes, they do. i don't need to argue about this. i agree they both move together on the track, but the gripper mechanism tilts forward to lock out and the diablo DOES NOT. that is independent.

6. ### IrvinG.O.A.T.

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Jim when you use the brake to string rackets does the string stay in the exact same place on that knob or (because of the rounded surface of the knob) does it tend to slide slightly off to the side? If the string does slide will the angle of the string going into the gripper remain the same?

I do agree my statement was not 100% correct

From RSI "One much-appreciated feature of the Star 5 is the return of the nosecone (or diabolo), which Babolat eliminated on the Sensor. Besides reducing the clamping force needed by the tension jaws, the nosecone also helps the operator position the string into the tension jaws the same way each time. As a result, the Star 5 is very gentle on delicate strings. We experienced no string scarring or marking due to the tension jaws."

7. ### DagsProfessional

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No, the one on the Wise doesn't spin. Early models did, but it was because the friction would cause the bobbin to unscrew rather than by design. In the later ones there's a chunk cut out of the bobbin so that the arm is embedded, which fixes this problem.

8. ### jim eHall of Fame

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When you wrap the string aroung that knob, and it is a sizable diablo on my machine, and when you pull at an angle like you would stringing some O Ports, since the knob is very smooth, the very beginning of the strings wrap may be off a mm approx. but the end of the wrap still would end in same position so the angle of the string to the plates would still remain the same.

Last edited: Nov 10, 2012
9. ### IrvinG.O.A.T.

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Thanks Dags good to know. So if i wanted to make my own diablo for my Wise i could weld (or bolt) a round piece of metal to a flat bar drill two holes in the side of the bar and bolt it to the side of the gripper assembly. Piece of cake.

Last edited: Nov 10, 2012
10. ### jim eHall of Fame

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Even easier you could purchase the so called "Gentle Jaws" diablo that was in an article in RSI a while back.

11. ### IrvinG.O.A.T.

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Do you still have a reference for those Gentle Jaws Jim? I was looking for it a while back and could not find it.

EDIT: Not sure but if I remember correct it was supposed to work on lockouts. If it works on lockouts it will not function to remove stress on an electronic.

12. ### IrvinG.O.A.T.

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Last edited: Nov 10, 2012
13. ### bugeyedSemi-Pro

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Originally Posted by Irvin
If that little knob does not spin then the string sliding on the knob creates friction and the tension on one side of the knob may be different. If the tension is lower on the side with the gripper there is less pressure on the string. In this instance the knob only functions to protect the string from the crushing force of the gripper.

Only correction I would suggest is to change "only" to "also".

Cheers,
kev

14. ### IrvinG.O.A.T.

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Why not just use what RSI (Babolat) said? But then again that is not really 100% correct either is it? From what I have heard with the overshoot on the Star 5 it is not so gentle on delicate strings.

Last edited: Nov 10, 2012
15. ### bugeyedSemi-Pro

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When using the brake in stringing an O port racquet on a Star 4, if the string is wrapped around the diablo, it does leave the diablo at an off center point on the racquet side. The gripper side of the string stays pretty well centered in the diablo. Therefore the diablo serves to keep the string properly positioned in the gripper.

Cheers,
kev

16. ### RabbitG.O.A.T.

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My own experience is this: When I first purchased my Wise, they did not supply a diabolo. I strung my C10s with natural gut. There was very visible ghosting on the string where the gripper clamped.

Herb sent me a diabolo. I attached it to the machine. I strung my racquet and there was visibly less ghosting on the string.

My immediate thought was the diabolo reduced the amount of pressure needed by the gripper to hold the string.

Using a poly to test this is really disingenuous since poly is pretty tough.

You can also try this, substitute your hand or fingers for the gripper. Set your tensioner to 30 pounds. See if it's easier to hold the string without slipping with or without the diabolo.

Last edited: Nov 10, 2012
17. ### bugeyedSemi-Pro

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I don't think that overshoot is much of a factor relative to the crushing force of the gripper. Sure you can argue that the increased pulling tension will be reflected at the gripper, but the major issue with the Star 5 overshoot is in the difference in the pulling tension.

Cheers,
kev

18. ### bugeyedSemi-Pro

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Thanks for posting your observation regarding the difference that the diablo made.
I do think, though, that some of the confusion on this issue is because of the various methods that diablos are employed on different machines. The facts that some spin & some are fixed & the diablos limited functionality on lock out machines needed to be established before there was any clarity.

Cheers,
kev

Last edited: Nov 10, 2012
19. ### RabbitG.O.A.T.

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Thanks, mine is fixed and does not spin

20. ### RabbitG.O.A.T.

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I have a Wise with a diabolo and it does not spin.

21. ### struggleHall of Fame

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I'm not sure the functionality is limited at all, it just works in a different way to accommodate the different operation of the tension head. Mine works great on my lockout.

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for me there was never any confusion. i owned the gamma 6004 which is a lockout w/ the metal diabolo that spins on a bearing and also had the wise with the fixed plastic/nylon diabolo that is fixed that i used on the gamma 6004. both diabolos functioned identically.

23. ### IrvinG.O.A.T.

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Are you trying to pick a fight?

24. ### RabbitG.O.A.T.

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Why not just call Herb and get him to send you one?

25. ### bugeyedSemi-Pro

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I thought that we established that the spinning diablo on a lock out machine serves to keep the string aligned with the gripper & not so much help, if any, with the gripper crushing force. A diablo on a machine like Babolat Star 4 serves the same purpose as on the lock out with the additional benefit of reducing the crushing force of the gripper. The method by which a lock out machine senses tension does not allow for the diablo to take any of the work away from the tension head. Therefore it does not change the tension seen by the gripper.

Cheers,
kev

26. ### IrvinG.O.A.T.

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^^There you go thinking again Kev. LOL I am just going to watch round two.

27. ### bugeyedSemi-Pro

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Me too. I was gone all day, so I thought I should make a contribution. I am through thinking for today.

Cheers,
kev

28. ### IrvinG.O.A.T.

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Just thinking about this today. If you don't use the diablo all the time you should see the sometime the tensioner is closer to the racket and some time farther away. This creates a different angle going into the gripper. The higher the string is (closer racket) the less force is required to lock out the crank.

Also the graduations on the tension dial are calibrated for a specific force to lock out the crank. if you string is above the diablo it would require less force to lock sonif you adjust at 60 lbs it may be right on but if you change the tension nyou could be off.

I think younshould always use the diablo no matter what type stringer you have.

29. ### struggleHall of Fame

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i've checked it both ways, no difference really (but i do see your point). I only don't use it on rare occasions, such as short on string.