To use diablo or not?

mad dog1

G.O.A.T.
My statements regarding lessened tension at the linear gripper are based on the Babolat machines & not lock out machines. On the CP machines, the gripper & diabolo relationship never changes. The "pull" is measured as the whole assembly moves. If Irvin is basing all of his argument on a lock out mechanism, that is a different issue, although his early statement that "I believe I seen a Babolat video that said it relieves the pressure on the gripper. Can't understand that but who am i to argue", would indicate that he was talking about the Babolat configuration as well.

Cheers,
kev

i have no idea what irvin is basing his position on , but the diabolo is attached to the crank mechanism and is fixed so it works the same way on a lockout as it does on electronic machines. the diabolo moves with the lockout tension head as the handle is cranked.
 

bugeyed

Semi-Pro
i have no idea what irvin is basing his position on , but the diabolo is attached to the crank mechanism and is fixed so it works the same way on a lockout as it does on electronic machines. the diabolo moves with the lockout tension head as the handle is cranked.

True, been a while since I used a lock out & I see that the diabolo is firmly attached to the gripper assembly, so they operate as a unit. I believe Irvin mentioned that, on his lock out machine, the gripper pivoted to trip the lock independently of the diablo. I think that's what he said. In that case, the gripper would need to see the full tension to trip the mechanism. I don't know of a machine that works like that though.

Edit: Yep, Irvin said, "The diablo on Gamma is fixed it can not move only the gripper rocks to lockout." There is the disconnect! I think. I'm so tired of this now!!!

Cheers,
kev
 
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Irvin

Talk Tennis Guru
I was talking about the Babolat configuration. I makes not difference if you have an electronic or lockout the diablo can not and does not lessen the stress on the string in the gripper. If you take a Babolat machine and run the string straight through the gripper and not around the diablo it will not make a difference.
 

Irvin

Talk Tennis Guru
i have no idea what irvin is basing his position on , but the diabolo is attached to the crank mechanism and is fixed so it works the same way on a lockout as it does on electronic machines. the diabolo moves with the lockout tension head as the handle is cranked.

By golly I think you are right on there.

EDIT: And that is the whole point of my argument that it works the same on an electronic (like a Babolat) as it does on a lockout (like my Gamma 6004.) It is just easier tonshow how the force on a lockout gripper has to be the same whether you go throu the diabloor not.
 
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bugeyed

Semi-Pro
Probably but it will not take any stress of the gripper.

Yes it will! Lessens the crushing of delicate strings. Or has this been covered before? It's like Deja vu all over again!
P.S. I gotta go to the store, so good luck all! Hope you can figure it all out.
Cheers,
kev
 

struggle

Legend
The diablo, er diabolo, on my 6004 does NOT move with the pivoting gripper mechanism, it is fixed to the tension head which does NOT rock/lock with lockout. Not sure what we are arguing here, just noting a fact.

As such, the gripper must place the same amount of grip whether the diabolo is used or not. it DOES, however, help out with the string angle going into the gripper. Again, just stating a fact.

I use it unless it is inconvenient, which is only occasionally, like when i start my mains.....even then i COULD use it, just don't........or if i'm short on string at the end of M/X.

Also, tension seems to pull the same, with or without. I have checked out of curiosity, just got the machine and thus a diablO last summer. I had never owned a machine with one (a diabOLO) before, only used them a couple times.

Carry on.
 

Irvin

Talk Tennis Guru
Thanks tbuggle. But I'm sure if you look real close you will notice the pivot point on the lower front of the gripper is fixed in position to the diablo. That distance never changes. As the whole assembly moves back and forth they move together. The only thing that rocks is the gripper assembly about the pivot.
 

uk_skippy

Hall of Fame
Other than answer the OP's question I decided not to get involved with the "discussion", until now.

A majority of top end machines have diabolos on them. There must be a reason why they're included. When the Babolat Sensor was released there was wonder why a diabolo wasn't included, and this is part of the reason it was included on the Star 5. At the French Open last year all the stringers were asked what they thought should be on their new machine, and a diabolo was one of the requirements that stringers wanted.

What a diabolo can also help with is the gripping point on the string. If you want to move the gripping point to a different point due it falling on a position where it could be at a critical point i.e. a bend, wrapping the string around the diabolo once or twice will help. Try and do that with a Sensor and it's a harder process to do as you'll have to let the tension head travel a bit before allowing to grip the string.

So, I believe the diabolo reduces the stress on the string, and the companies that make the machines seem to think that the inclusion of it is a good idea. And that is good for me.

Regards

Paul
 

Irvin

Talk Tennis Guru
^^Paul I agree that the diablo is a good thing. But other than the fact that you have just heard it reduces stress on the string do you have any idea of how? What I am not buying is that the friction of the diablo cuts down on the crushing effect in the gripper, but there are advantages.
 

jeroenn

Semi-Pro
If you take a Babolat machine and run the string straight through the gripper and not around the diablo it will not make a difference.


It will.

It's plain physics, sir. The friction of the string around the diabolo alone will take pressure off the gripper. Distribution of forces of the string wrapped around the diabolo will take pressure off the gripper.

Arguing that it won't is like arguing that the earth is flat....

j
 

Irvin

Talk Tennis Guru
It will.

It's plain physics, sir. The friction of the string around the diabolo alone will take pressure off the gripper. Distribution of forces of the string wrapped around the diabolo will take pressure off the gripper.

Arguing that it won't is like arguing that the earth is flat....

j

OK now we have a physicist in the mix. Please tell us what physics principal causes the reduction in stress. I am all ears.
 

jeroenn

Semi-Pro
I just did...?

Friction & distribution of force.

Replace diablolo with finger, you'll feel the friction & forces.

J
 

Irvin

Talk Tennis Guru
Maybe it will help if you first understand what friction is. Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.

Ref - http://en.wikipedia.org/wiki/Friction

Do you really think the string is sliding around the diablo?
 

jeroenn

Semi-Pro
I know what friction is, thankyouverymuch.

Would you now like to go ahead and argue that when there is no slipping (motion) between your clutch plates in your car while driving, there's no friction between them?

I don't think the string is sliding around the diabolo. I do think there's friction between the diabolo and string, and the string wrapped next to each other.

I also think that the diabolo as a whole takes pressure of the gripper by distributing tension to itself and it's mounting point.
 

struggle

Legend
Thanks tbuggle. But I'm sure if you look real close you will notice the pivot point on the lower front of the gripper is fixed in position to the diablo. That distance never changes. As the whole assembly moves back and forth they move together. The only thing that rocks is the gripper assembly about the pivot.

Yes, the pivot point does not move, how could it? But the gripper DOES move independently of the diablo. The gripper jaws become closer to diablo as tension is applied, but not much. Anyhow, the diablo is fixed, the gripper is not....based on my observation (machine is sitting next to me).

I do think the diablo takes some stress off the whole scenario, but it doesn't change the tension whatsoever. Like you (i think), I believe it eases the angle into the gripper. Works for me.
 

struggle

Legend
Do you really think the string is sliding around the diablo?

mine has a NICE bearing in it, no sliding going on. It's like a skateboard wheel, very little rolling resistance, i suspect the tension head/gripper barely detects it, if at all.
 

uk_skippy

Hall of Fame
But other than the fact that you have just heard it reduces stress on the string do you have any idea of how?

TBH the reference to reduce the stress on the string is stated by Babolat in the documentation I received when introducing the machine. It does not explain how. I know that the whole point of the Sensor (and the Star 5) is that the electronics "sense" the string so that it can accurately pull and maintain the required tension. But again, I do not know exactly how that works; and I do not (really) need to know.

I am confident that the diabolo is there for a reason and accept the reason given. I 'feel' that the string is under less stress when I use the diablo, and as mentioned, I double wrap the string for further protection if required.

Regards

paul
 

jeroenn

Semi-Pro
Again, the diablo does NOT move with the gripper, but they are both attached to the tension head.

I know. If it was a seperate piece, it wouldn't take stress off the gripper.

It would pull string ==> diabolo ==> gripper.

It is because they are attached, it will help relieve. The gripper plates will have to work less hard because the diabolo carries part of the weight.

It's like a pair of pliers. If you wind the string around the handle of the pliers, you'll have to squeeze less hard to be able to pull the same tension before the string slips. Same principle.
 

bugeyed

Semi-Pro
mine has a NICE bearing in it, no sliding going on. It's like a skateboard wheel, very little rolling resistance, i suspect the tension head/gripper barely detects it, if at all.

That mechanical setup is a different animal than the Babolat arrangement. Your diabolo needs to rotate freely so that the gripper "sees" the complete string tension. If it did not let the string slide through, the gripper would not lock out properly (at the proper tension). That is a different machine. The Babolat configuration works differently & does share the load. The tension measurement is done by a load cell that senses the tension that is felt by the shuttle relative to the chassis. Both the diabolo & linear gripper are firmly attached to the shuttle & do not move independently of each other. That's why the diabolo works to take part of the load.

Cheers,
kev
 

Irvin

Talk Tennis Guru
Ever wonder why you have never seen a diablo on anything but a linear gripper?

The diablo does move with the LINEAR gripper.

Ever wonder why engineers use pulleys and levers instead of diablos? They must be out of their minds. Why would you ever want to use pulleys and levers when you can get a mechanical advantage with a diablo?
 

struggle

Legend
so the diablo on an electric does not spin on a bearing?

I have used a gamma electronic, but really did not pay attention to how it worked, i was too busy stringing rackets.
 

struggle

Legend
The diablo does move with the LINEAR gripper.

it does NOT, at least on a gamma 6004. The gripper pivots (to lockout) and the diablo does NOT. sorry, but i'm looking at one right now, simply not true. If i manulally pivot my gripper to cause it to lockout, the diablo does not flinch as the gripper head move s upon a pivot.

edit: They do moth move "together" as the head rolls upon the arm, however. But upon the tension head itself, the gripper moves and the diablo does not.
 
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Irvin

Talk Tennis Guru
it does NOT, at least on a gamma 6004. The gripper pivots (to lockout) and the diablo does NOT. sorry, but i'm looking at one right now, simply not true. If i manulally pivot my gripper to cause it to lockout, the diablo does not flinch as the gripper head move s upon a pivot.

You are right. But if the tensioner slides back 3" the diablo slides back 3" and the gripper slides back 3". I agree the gripper assembly does tilt up slightly so the catch lift off the lockout lever but the whole assembly moves 3".
 

jim e

Legend
so the diablo on an electric does not spin on a bearing?

I have used a gamma electronic, but really did not pay attention to how it worked, i was too busy stringing rackets.

On my Pro Master machine, the diablo does not spin at all, but does move with the tension plates when tension is pulled. It works great as the string enters the tension plates at same angle each time, and with nat. gut if I need to pull the same string twice, I would wind the string a second time around the diablo so the tension plates would not press on the same spot twice. A nice feature to have.

This diablo is nice and large, and is very smooth. It handles the angled pulls very nice when the brake is locked stringing O Port racquets so I never need to use boomerangs or s hooks or any other items between strings like some do as the brake along with the diablo the string will not pull on a severe angle against the linnear plates as the diablo handles the pull very nice. Its a great feature to have especially stringing delicate strings.

Picture of it below:

IMG_0841.jpg
 

struggle

Legend
i can see that working, and the jaws gripping the string "less" as the whole gripper/diablo unit is sensing the tension (load sensor or whatever). Different than on a lockout with diablo.
Either way, i agree that the angle to the jaws is the key reason for them. And that is what lessens, to a degree, "damage" to the string.

heck, i bet on that machine you could multi-wrap the string about the diablo and hold it place with your hand, never using the gripper....and still pull at proper tension. feelin' me?
 
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mad dog1

G.O.A.T.
i can see that working, and the jaws gripping the string "less" as the whole gripper/diablo unit is sensing the tension (load sensor or whatever). Different than on a lockout with diablo.
Either way, i agree that the angle to the jaws is the key reason for them. And that is what lessens, to a degree, "damage" to the string.

heck, i bet on that machine you could multi-wrap the string about the diablo and hold it place with your hand, never using the gripper....and still pull at proper tension. feelin' me?

exactly. this is why the gripper doesn't need to clamp on the string as hard when there's a diabolo in use.
 

struggle

Legend
exactly. this is why the gripper doesn't need to clamp on the string as hard when there's a diabolo in use.

i assure you, it (gripper) clamps just as hard on my 6004, as the gripper and diablo DO move independently of each other (and the diablo is just a roller). but it does reduce stress to the string, i agree.....but that has more to do with string angle into the jaws.

i can run the string through the diablo or NOT and still get the same tension reading on a calibrator. I could NOT however only run the string around the diablo.....it would NEVER lockout. Never, ever.
 

uk_skippy

Hall of Fame
heck, i bet on that machine you could multi-wrap the string about the diablo and hold it place with your hand, never using the gripper....and still pull at proper tension. feelin' me?

I just checked this on my Star 5, and yes it worked. I wrapped the (synthetic) string around the diabolo 10 times and gently held the string while the tension head pulled it. As long as I held it so the string wouldnt unravel it worked.

Regards

Paul
 

struggle

Legend
^^^ i bet it would work with gut too!! haha, just kidding. i figured it would, but i'm a lowly lockout man!!

thanks!
 

Spinaway

New User
I am with Irvin on this one with the diablo controversy.
I have recently made a diablo for my own crank stringer and prior to that had to satisfy myself that I did understand what it was really there for.
The sole and only reason for the diablo, on a crank stringer, is to mechanicaly align the string to enter the gripper dead square every time. Any time the string lays between the gripper jaws out of square there is the possibility that during the tension pull the string moves in the jaws .... this is probably what is being seen as increased flattening of the string that lay inbetween the jaws on a non diablo tensioner.
After making my diablo I did a lot of tension tests and found no measurable change in the calibration of the machine, the full tension of the gripper was being applied to the string in the racquet area. No measurable tension loss in the diablo pully.
 

bugeyed

Semi-Pro
I am with Irvin on this one with the diablo controversy.
I have recently made a diablo for my own crank stringer and prior to that had to satisfy myself that I did understand what it was really there for.
The sole and only reason for the diablo, on a crank stringer, is to mechanicaly align the string to enter the gripper dead square every time. Any time the string lays between the gripper jaws out of square there is the possibility that during the tension pull the string moves in the jaws .... this is probably what is being seen as increased flattening of the string that lay inbetween the jaws on a non diablo tensioner.
After making my diablo I did a lot of tension tests and found no measurable change in the calibration of the machine, the full tension of the gripper was being applied to the string in the racquet area. No measurable tension loss in the diablo pully.

The same is not true of a linear pull Babolat type machine. As I stated before, a lock out machine does not work the same.

Cheers,
kev
 

mad dog1

G.O.A.T.
...After making my diablo I did a lot of tension tests and found no measurable change in the calibration of the machine, the full tension of the gripper was being applied to the string in the racquet area. No measurable tension loss in the diablo pully.

the use of the diabolo does not change the reference tension being pulled. if your reference tension is 60#, the tension should be 60#s whether you use the diabolo or not. the point is when the string is wrapped around the diabolo, the clamping plates of the string gripper don't need to clamp as hard so it's easier on the string. see uk_skippy's post below.

I just checked this on my Star 5, and yes it worked. I wrapped the (synthetic) string around the diabolo 10 times and gently held the string while the tension head pulled it. As long as I held it so the string wouldnt unravel it worked.

Regards

Paul
 
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mad dog1

G.O.A.T.
i can't even believe there's a debate on this topic. it seems like common sense, but then again, this is the TW forum where common sense just isn't so common.
 

struggle

Legend
the use of the diabolo does not change the reference tension being pulled. if your reference tension is 60#, the tension should be 60#s whether you use the diabolo or not. the point is when the string is wrapped around the diabolo, the clamping plates of the string gripper don't need to clamp as hard so it's easier on the string. see uk_skippy's post below.

oh jeez. i assure you, the diablo DOES function differently (with a similar result) on a lockout vs. an electronic machine (as uk skippy was referring to).
the diablo on my lockout must grip the string the same whether using the diablo or not, just the string angle is eased into the gripper when diablo is used.

try it. at any rate, diablo is a good thing....no matter the machine type, etc. agreed.

cheers!!! (slurp)
 

Irvin

Talk Tennis Guru
... i bet on that machine you could multi-wrap the string about the diablo and hold it place with your hand, never using the gripper...

I'd take that bet. Jim e try setting the tension real low and wrap it around the diablo a couple time and seeif you can hold it easily.
 

Irvin

Talk Tennis Guru
...the gripper and diablo DO move independently of each other ...

tbuggle look on the right side of your tensioner. In the top left you have the diablo with a steel bar leading down to the gripper assembly. There is a pin that goes through the steel bar and through the gripper assembly. There is no way that gripper assembly and move independent to the diablo. The gripper plates inside the assembly do move to close and open on the string but the gripper assembly moves when the diablo does.
 

Irvin

Talk Tennis Guru
I just checked this on my Star 5, and yes it worked. I wrapped the (synthetic) string around the diabolo 10 times and gently held the string while the tension head pulled it. As long as I held it so the string wouldnt unravel it worked.

Regards

Paul

If your diablo does not spin you have friction. Does you diablo spin?
 

Irvin

Talk Tennis Guru
On my Pro Master machine, the diablo does not spin at all, but does move with the tension plates when tension is pulled. It works great as the string enters the tension plates at same angle each time, and with nat. gut if I need to pull the same string twice, I would wind the string a second time around the diablo so the tension plates would not press on the same spot twice. A nice feature to have.

This diablo is nice and large, and is very smooth. It handles the angled pulls very nice when the brake is locked stringing O Port racquets so I never need to use boomerangs or s hooks or any other items between strings like some do as the brake along with the diablo the string will not pull on a severe angle against the linnear plates as the diablo handles the pull very nice. Its a great feature to have especially stringing delicate strings.

Picture of it below:

IMG_0841.jpg

jim e does your diablo spin?
 

Irvin

Talk Tennis Guru
I think I may understand what some of you are saying now. If I wrap a string around a post and pull on it I can hold more tension that what is on the other side of the post. But the smoother that string is and the smoother that post is the more equal the tension on each side of the post will be.

If that post is allowed to spin it would be as though it were not even there the tension on either side would be the same. Now you must understand what I am saying. My diablo spins very freely there is not friction as the string is not sliding on the diablo and it would IF the diablo did not spin.

But I still can not see how as smooth as the strings are and the diablo is there is enough friction to make a difference unless you wrap it over and over and even possibly overlap the strings.

On a Gamma 6004 it does not take any pressure off the string in the gripper.
 

Irvin

Talk Tennis Guru
i can't even believe there's a debate on this topic. it seems like common sense, but then again, this is the TW forum where common sense just isn't so common.

I bet by the time the debate is over everyone understands the principles behind a diablo and how they differ on different models of stringing machines.
 

Irvin

Talk Tennis Guru

bugeyed

Semi-Pro
I think I may understand what some of you are saying now. If I wrap a string around a post and pull on it I can hold more tension that what is on the other side of the post. But the smoother that string is and the smoother that post is the more equal the tension on each side of the post will be.

If that post is allowed to spin it would be as though it were not even there the tension on either side would be the same. Now you must understand what I am saying. My diablo spins very freely there is not friction as the string is not sliding on the diablo and it would IF the diablo did not spin.

But I still can not see how as smooth as the strings are and the diablo is there is enough friction to make a difference unless you wrap it over and over and even possibly overlap the strings.

On a Gamma 6004 it does not take any pressure off the string in the gripper.

There is a bit of friction where the strings cross beside each other. The shape of the diablo forces the string to the center, on the Babolat Star 4 anyway. The Babolat has a V shaped, rather than some that have a flat in the trough. As well as the fact that the string is tightening around the diablo as it pulls. Not saying that one wrap takes most of the force, just that it offsets the forces that the gripper sees.

Cheers,
kev
 
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Spinaway

New User
In this diablo discussion we need to be aware of a distinction in diablos between a crank/lockout machine and an electronic head machine.

On an electronic head machine the diablo position is rigidly fixed to the structure that holds the gripper plates, and travels with it exactly. This is regardless of whether it has a fully rotating ball bearing diablo pulley or a non-rotating smooth pulley. The tension measurement is done by an electronic sensor that measures the total force resisting the movement of this tension head assembly. This tension sensor does not care how the force it measures is achieved, whether it be force resistance in the gripper or friction from the diablo pulley, or the sum of the two. So the manufacturer of this type of machine can elect to have a non-rotating, friction inducing, diablo pulley if he wishes. The net result of that would be that, apart from doing its primary job of aligning the string correctly into the gripper, it could have a secondary function of taking some of the pulling force off the gripper plates. Maybe wind it around the fixed diablo twice to induce greater friction loss for some delicate strings that get unduely squashed between the gripper plates at higher tensions.... for example.

For the crank stringer we can not tolerate any measurable friction losses in the diablo pulley otherwise it would affect the tension calibration of the machine. Diablos on cranks are not attached to the gripper head, they are attached to the support arm for the gripper head. The tension measurement on a crank is done from the pivoting action of the gripper head only, so any frictional losses induced in the string after the nose of the gripper plates, will be deducted from the actual string tension achieved.
 
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