Drop Weight Vs. Crank

[taneepak]

A crank machine may be out of calibration by say 2lbs, in which the reading says 30lbs but the out of calibration tension is actually 28lbs. Precise tension on every pull means you get 28lbs on every pull. It doesn't mean you must get 30lbs. Drop-weight machines would have varying tension for each drop.

[cooler]

A crank machine may be out of calibration by say 2lbs, in which the reading says 30lbs but the out of calibration tension is actually 28lbs. Precise tension on every pull means you get 28lbs on every pull. It doesn't mean you must get 30lbs. Drop-weight machines would have varying tension for each drop.

i understood what u meant but i think u didnt understand our, every crank still wouldn't give u duplicate tension, it fluctuate a bit around a mean.

[Neil Nicholls]

Drop-weight machines would have varying tension for each drop.

Apart from the Laserfibre and similar systems, yes.
But varying by how much?

If you get the bar exactly horizontal, you get 100% of your reference tension.
If you are 5 degrees out, you get 99.62% of your reference tension.
If you are 10 degrees out, you get 98.48% of your reference tension.

reference = 24 lb
5 degrees out -> 23.909 lb
10 degrees out -> 23.635 lb

On a 12 inch bar, 5 degrees out is 1 inch above or below at the far end of the bar.
I doubt if my bar is ever more than 1cm out of horizontal, which is about 1.9 degrees.
If you are 1.9 degrees out, you get 99.945% of your reference tension.
1.9 degrees out -> 23.987 lb

[DinkAlot]

A crank machine may be out of calibration by say 2lbs, in which the reading says 30lbs but the out of calibration tension is actually 28lbs. Precise tension on every pull means you get 28lbs on every pull. It doesn't mean you must get 30lbs. Drop-weight machines would have varying tension for each drop.

Yes, you will get 28lbs. once the crank locks. Again, however you need to remember, the tension starts to drop and continues to drop due to creep, until you clamp. And even then you lose a bit of tension but we'll assume ceteris paribus on the clamping.

The only way to avoid the creep is a constant pull machine.

[LazyBuddy]

When I get my rackets done by them, I specifically ask them to do it on the Prince Neo 1000 strining machine (a crank strining machine). Mainly for consistancy of the tention which I ask for.

I believe the cranking machines usually having trouble to main the tension consistancy, unless they re-cal their machine on a very regular basis.

[silentheart]

A crank machine may be out of calibration by say 2lbs, in which the reading says 30lbs but the out of calibration tension is actually 28lbs. Precise tension on every pull means you get 28lbs on every pull. It doesn't mean you must get 30lbs. Drop-weight machines would have varying tension for each drop.

I have to repectfully diagree with you on your post. Just like Neil Nicholls posted earlier, an experienced drop weight stringer can get the bar near horizontal almost every time. That means drop weight is very close to the ref tension every time. However, there are many more parts for crank machine that cause varience. I agree with your observation that crank machine will give you same tension on every pull. However, I would like to add that it is true for the same racquet during that string job. Some crank machine (or cranky machine) might be out of calibration every month. If a person use those machine, the string tension might be different from job to job.

Alos, I would like to point out that as you posted, reference tension says 30lb and you are getting 28lb. It might be OK for yourself, is it OK for your customer (or friend) when they requested 30lb? This is what I worry about when I use different stringing service because you can not be sure you get the same tension from 1 stringer to another.

[LazyBuddy]

I have to repectfully diagree with you on your post. Just like Neil Nicholls posted earlier, an experienced drop weight stringer can get the bar near horizontal almost every time. That means drop weight is very close to the ref tension every time. However, there are many more parts for crank machine that cause varience. I agree with your observation that crank machine will give you same tension on every pull. However, I would like to add that it is true for the same racquet during that string job. Some crank machine (or cranky machine) might be out of calibration every month. If a person use those machine, the string tension might be different from job to job.

I agree.

Further more, the "pull" is not the only step to determine the final tension. For crank machine, the "pull" might be consistant, but after count in the lost tension (e.g. where and hot tight you place the clamp) will result in different tension for each piece, as crank is not constant pulling machine.

For drop weight, it's the opposite. Yes, maybe each pull might have small variance, but since it's a constant pulling machine, you can "re-adjust" the last 1-2 piece of string if you let the leveler sit for several more seconds. Therefore, with the adjustment, the difference in final result is very much minimized.

[taneepak]

Some stringing machine manufacturers make only drop-weight machines or only crank machines. Very few make the complete range of drop-weight, crank, and electronic machines. I believe manufacturers of the complete range will not claim that the drop-weight delivers precise tension with each pull, but they will claim that for the crank and the electronic.

[cooler]

Some stringing machine manufacturers make only drop-weight machines or only crank machines. Very few make the complete range of drop-weight, crank, and electronic machines. I believe manufacturers of the complete range will not claim that the drop-weight delivers precise tension with each pull, but they will claim that for the crank and the electronic.

i think u rely on factory claims more so than from self observation (like in the case before where u had errored on string replusion by relying on yonex string chart for replusion comparison) Drop weight is a simple concept. As neil had pointed out, cos of 0,1,2,3,4,5,6,7,8,9,10 degree is less than 1.5% error, well under any crank tension inconsistenties.

[LazyBuddy]

Some stringing machine manufacturers make only drop-weight machines or only crank machines. Very few make the complete range of drop-weight, crank, and electronic machines. I believe manufacturers of the complete range will not claim that the drop-weight delivers precise tension with each pull, but they will claim that for the crank and the electronic.

Manufactures always try to promote the more expensive models as that's no secret. They over hype the good features, and try to hide aways the cons. Plus again, the string process is much more complicated than a simple "pull", and I am sure you know that much better than a lot of us.

[Matt]

I believe the cranking machines usually having trouble to main the tension consistancy, unless they re-cal their machine on a very regular basis.

Since they are one of the popular local stores, they do calibrate their machines on a regular basis.

What I meant more about consistency is that I want the stringing to be done on the same stringing machine. This is because in the past, when wanted my racket to be stringed at tension X, the sound (the note to be exact, since I do know music) was inconsistent as the racket sounded low, or sometimes high. I kept adjusting the tension numbers to figure out why this was happening.

It was later determined that, the racket was not being stringed on the same stringing machine, as sometimes it was done on the crank and sometimes the electronic which would explain the inconsistencies. The simple solution is to have the rackets done on the same machine, and as a result, the sound matches the tension which I asked for.

So, if I wanted my rackets to be stringed on the electronic, I’ll have to figure out the sound tension equivalency on each machine, since have a Prince and Babolat electronic machines.

[taneepak]

Manufactures always try to promote the more expensive models as that's no secret. They over hype the good features, and try to hide aways the cons. Plus again, the string process is much more complicated than a simple "pull", and I am sure you know that much better than a lot of us.

True, if a manufacturer produces just one type, i.e. drop-weight, it will cliam its the best. Ditto for others for make one or two types. But for manufacturers who make all types, surely they want to promote all the three types; and I would think they would be more even handed and credible than manufacturers who specialize in making just one type.

[taneepak]

If you think about it the use of the words "constant pull" is confusing. Perhaps there is no such thing and is simply used, wrongly, to mean the pull is continuous for only the time between reaching the desired tension and the clamping of the clamp. Now what happens after the clamping? Whether it is crank, drop-weight, or electronic, the same after clamping dynamics apply. In fact in the time to get ready for the next pull-the faster, more uniform, and shorter the pull the better-the dropweight is the slowest. Using a tennis drop-weight machine for badminton racquets makes it even worse-longer string to pull and a longer in-between pulls. A tension drop-out, whether at reaching the desired tension (as in the crank) or when clamping the clamp, is still a tension drop-out, for all types of machines. Where then is the "constant pull"?

[Pete LSD]

Why are you even talking about the time between after clamping and the next pull? This is a non issue.

[taneepak]

Why are you even talking about the time between after clamping and the next pull? This is a non issue.

How about this : if a machine spends 90% of its stringing time on non-constant pull mode, why call it a constant pull machine? This is the time (locked-out time) when tension starts to loosen. Isn't this a major issue, since it is so misleading?

[Pete LSD]

The machine doesn't spend 90% of its time in between pulling time: more like 5 seconds from clamping to retensioning.

Most of the time spent is waiting for the string under tension to stretchhhhhhhhhh and stretchhhhhhhhhhhhhhhhhhhh until it doesn't stretch or the stringer get sick and tire of waiting.

How about this : if a machine spends 90% of its stringing time on non-constant pull mode, why call it a constant pull machine? This is the time (locked-out time) when tension starts to loosen. Isn't this a major issue, since it is so misleading?

[silentheart]

How about this : if a machine spends 90% of its stringing time on non-constant pull mode, why call it a constant pull machine? This is the time (locked-out time) when tension starts to loosen. Isn't this a major issue, since it is so misleading?

Most of the crank machine spent >95% of the time in no pull mode after the break applied. We agree with you that crank machine can produce consist pull during 1 string job. However, any string machine face the same problem that you mentioned. This is a none issue. if you compare apple to apple (constant pull with fix clamp vs crank with fix clamp) or orange to orange (constant pull with fly clamp vs crank with fly clamp) what you brought up is not an issue at all.