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KoaUka
02-06-2012, 12:12 PM
Hello,

Just out of curiousity, does anyone know the advantages/disadvantages of using two clamps when stringing the crosses?

This applies to fixed clamps, two piece job.

I've heard to just use one, cause all you need is one...
However, i've seen some videos where it "appears" that they are using two clamps when doing the crosses. Does it matter? Is one way better than the other?

Thank you

Irvin
02-06-2012, 12:17 PM
That depends on the clamps. If you have glide bar clamps than slide from side to side you can get by with one. If you don't you must use two.

KerryR
02-06-2012, 12:25 PM
The main reason to use 2 clamps on the crosses is to prevent accidental release of tension-- when only one clamp is used and the tensioner accidentally releases while you're moving the clamp, or the clamp is accidentally released before the tensioner is fully engaged, all the crosses will need to be re-strung (or the entire job in a one piece). This only ever happens when you're under the biggest time constraint...

On machines with glide bars, like the Neos 1000, one clamp for the crosses is standard practice, even though there's a 2-clamp option for these machines. Accidents are rare, but when it happens, it can be a real pain.

KoaUka
02-06-2012, 12:27 PM
Alpha DC plus clamps. They glide and swivel I believe.

Irvin
02-06-2012, 12:44 PM
For a machine like this one the clamp on the left will not reach the strings on the right and vice-a-versa.

http://www.photostringer.com/images/061110-058b1.jpg

KoaUka
02-06-2012, 01:23 PM
Ah yes, I see.

I guess i should've said, when going from side to side, is it bad to leave both clamps clamped? That's what it appears YuLitle is doing in the video.

It seems theres some who do it as a preventative measure. I was just wondering if it creates more tension loss by leaving both clamps clamped and just removing them as needed.

Irvin
02-06-2012, 02:11 PM
YULitle has swivel clamps similar to the picture above. One clamp is for your odd crosses and the other for you even crosses. When pulling tension on one cross string the clamp on the opposite side must hold the one above the string you are tensioning while you move the clamp from two above down to the string your are tensioning.

diredesire
02-06-2012, 03:31 PM
The main reason to use 2 clamps on the crosses is to prevent accidental release of tension-- when only one clamp is used and the tensioner accidentally releases while you're moving the clamp, or the clamp is accidentally released before the tensioner is fully engaged, all the crosses will need to be re-strung (or the entire job in a one piece). This only ever happens when you're under the biggest time constraint...

On machines with glide bars, like the Neos 1000, one clamp for the crosses is standard practice, even though there's a 2-clamp option for these machines. Accidents are rare, but when it happens, it can be a real pain.

As irvin said, the main reason to use 2 clamps is if you need to by necessity. It's actually EXTREMELY inconvenient to do with a neos unless you are using half-width glide bars, and those have their own set of problems/non-idealities.

If you used two full length glide bars, one would actually block the other half the time... One bar is preferred for this reason.

Ah yes, I see.

I guess i should've said, when going from side to side, is it bad to leave both clamps clamped? That's what it appears YuLitle is doing in the video.

It seems theres some who do it as a preventative measure. I was just wondering if it creates more tension loss by leaving both clamps clamped and just removing them as needed.

It's preference at this point, when your clamps don't block one another. It's not "more" proper to do one or the other. It actually requires work to remove a clamp when moving down the string bed, when it could be acting as 'cheap security.' I personally DO pop the clamp and get it out of the way while stringing, but I assume the majority of stringers out there leave the backup on.

mmk
02-06-2012, 03:59 PM
... It actually requires work to remove a clamp when moving down the string bed, when it could be acting as 'cheap security.' ...

That 'cheap security' has saved me a couple of times.

KoaUka
02-06-2012, 04:39 PM
Thanks DD & Irvin. I appreciate your input.

My friend gave me a weird look when I told him I leave the clamp on..

It seems it's all preference, and neither way is right or wrong??

Irvin
02-06-2012, 05:06 PM
...If you used two full length glide bars, one would actually block the other half the time... One bar is preferred for this reason...

There is one time when two full length glide bar do work and don't get in the way. When you're stringing a two piece 50/50 pattern. Then one glide bar is used for the top half of the crosses and the other for the bottom half of the crosses. But then you are using one clamp for both side just one for the top and the other for the bottom.

diredesire
02-06-2012, 06:46 PM
That 'cheap security' has saved me a couple of times.
I'm not saying it's not useful ;) Like I said, I'm probably in the minority that would actually go through the trouble of releasing the trailing clamp. In my stringing career, I've had times where the string catches on a clamp handle and releases, but those are extremely rare, and due to sloppiness on my part.

Thanks DD & Irvin. I appreciate your input.

My friend gave me a weird look when I told him I leave the clamp on..

It seems it's all preference, and neither way is right or wrong??

If your friend strings with a NEOS or something, then OK, it might be weird to him if he's never tried anything else. If you're using fixed, rail/dual action clamps, I'd say it's more weird to NOT keep the backup clamp on. I just like having space to work. No single way is "more correct," although you could argue keeping the backup clamp on is better (for reasons discussed above).

There is one time when two full length glide bar do work and don't get in the way. When you're stringing a two piece 50/50 pattern. Then one glide bar is used for the top half of the crosses and the other for the bottom half of the crosses. But then you are using one clamp for both side just one for the top and the other for the bottom.
Good point. Gotta trust in Irvin to think outside the box :)

gotwheels
02-06-2012, 07:04 PM
The method of only having one clamp at any time clamping the cross will result in a higher stringbed stiffness as compared to having two clamps at any one time on the crosses [easier to do with a constant pull style stringer]. As others have said, the use of two clamps provides back-up security if one accidentally releases a clamp prematurely with a string loop or an uh-oh moment.

This method allows a slight stringbed adjustment if you think the chosen reference tension is a little low, once you have started the stringing process [example would the first time stringing of a new string], assuming that you typically use two clamps for the crosses.

Irvin
02-07-2012, 02:35 AM
'gotwheels' just curious why do you think one way will result in a higher SBS than the other?

gotwheels
02-07-2012, 07:29 AM
Hi Irvin, It is not "thinking" but a quantitative determined observation (not originated by me, but by those who have forgotten more about stringing than I will ever hope to know - the J. Gugel and A. Lees' of the world!). The explanation for the increase in stringbed stiffness or dynamic tension, when using a single clamp, is the incremental gains from minimalizing the tension losses in the clamping process (the clamping process, clamp drawback, pull angle, various other losses) that are not able to be recovered with two clamps. You are just pulling back a little of the "lost" tension, as you proceed down the stringbed.

This is measurable quantity (not a large number) with the "relative" measure of a String Meter or the various dynamic tension measurement instruments.


"One knows not where they are going until they understand where they have been."

diredesire
02-07-2012, 08:17 AM
Hi Irvin, It is not "thinking" but a quantitative determined observation (not originated by me, but by those who have forgotten more about stringing than I will ever hope to know - the J. Gugel and A. Lees' of the world!). The explanation for the increase in stringbed stiffness or dynamic tension, when using a single clamp, is the incremental gains from minimalizing the tension losses in the clamping process (the clamping process, clamp drawback, pull angle, various other losses) that are not able to be recovered with two clamps. You are just pulling back a little of the "lost" tension, as you proceed down the stringbed.

This is measurable quantity (not a large number) with the "relative" measure of a String Meter or the various dynamic tension measurement instruments.


"One knows not where they are going until they understand where they have been."

Not just minimizing tension loss, per se, but when you pop the sole clamp, the tiny bit of drawback that isn't recovered will be pulled out. This will generally promote overcoming the high friction force and allow a little bit of the untensioned "bend" section to be pulled out (assuming your CP tensioner will re-engage with the very slight tension change). I'd wager with a crappy tensioner you won't notice/measure a difference.

Irvin
02-07-2012, 11:24 AM
... You are just pulling back a little of the "lost" tension, as you proceed down the stringbed....
Not just minimizing tension loss, per se, but when you pop the sole clamp, the tiny bit of drawback that isn't recovered will be pulled out...

If it is a tiny bit of tension that is being pulled out then I guess that means it is OK to double pull strings as the tension in the pulled string and the next will be the same? I don't think so. You may have some tension pulled out but not a tiny bit. Unless that tiny bit still leaves a 3 or 4 pound difference in the two strings.

I notice this when I start my mains I tension and clamp three strings on one side of the racket then go back to the first mains on the opposite side. When I tension the string and pop the clamp the Wise will immediately pull more tension sometimes. It depends on the string. With a softer string that stretches a lot yes but if I am using a stiffer poly no. And that is because I have a constant pull. If using a lockout that would not happen unless I double pulled after the clamp was removed and I would not recommend that. If you removed you clamp and then release the tension there will be drawback in the previous string that will never be recovered.

It may make a small difference sometimes but not all the time.

Irvin
02-07-2012, 12:26 PM
Hello,

Just out of curiousity, does anyone know the advantages/disadvantages of using two clamps when stringing the crosses?...

One advantage would be the last clamp used to clamp the string above the string you are tensioning is helping to hold the racket in place.

diredesire
02-09-2012, 10:30 AM
If it is a tiny bit of tension that is being pulled out then I guess that means it is OK to double pull strings as the tension in the pulled string and the next will be the same? I don't think so. You may have some tension pulled out but not a tiny bit. Unless that tiny bit still leaves a 3 or 4 pound difference in the two strings.

I notice this when I start my mains I tension and clamp three strings on one side of the racket then go back to the first mains on the opposite side. When I tension the string and pop the clamp the Wise will immediately pull more tension sometimes. It depends on the string. With a softer string that stretches a lot yes but if I am using a stiffer poly no. And that is because I have a constant pull. If using a lockout that would not happen unless I double pulled after the clamp was removed and I would not recommend that. If you removed you clamp and then release the tension there will be drawback in the previous string that will never be recovered.

It may make a small difference sometimes but not all the time.

I didn't imply that all tension was being pulled out. Nor did I imply that the forces of friction are overcome, the opposite in fact. We're talking about very slight (but measurable) differences in SBS.

As far as sometimes vs all the time, yes, this is obviously going to be exaggerated by certain string types (nothing is ever "set in stone," in terms of predictability). For instance if a poly bends tightly around a grommet, it's going to resist re-pulls moreso than a softer string.

Agreed on this effect being seen (much moreso) on a CP than a crank (as gotwheels mentioned).