Discussion in 'Stringing Techniques / Stringing Machines' started by haderech, Jul 27, 2010.
I'm concerned with exceeding the recommended tension range of my racquet.
it's a drop weight. it should be accurate pending the user.
gravity is a beautiful thing. read the directions and have at it.
i consider a dropweight system to be as accurate as one can get.
likely, the only thing that would cause inaccuracy of the machine would be a misplaced sticker on the bar.
heck, it may not even have a sticker and be engraved for all i know.
there was a diagram showing the inaccuracy of a drop weight machine, but it showed that the maximum tension achieved was the tension you set as the reference and any angle other than horizontal the tension pulled would be less than the set tension. so as long as you set the reference tension less than the highest recommended tension you should be fine. only time i can see it going over is if you force the drop weight lever to go lower than gravity will take it.
I always found mine to be right on the money. I don't use it any more, but I can still count on it as an accurate backup.
As far as the tensioner is concerned it should be right on the money. And it is constant pull so if the frame is moving while you clamp and release your clamps the tensioner will adjust to the right tension.
I would be more concerned about the clamps. Flying clamps damage string more than fixed, glade or swivel clamps. Imo the upgraded machines are worth the money
It should be right on the money but what is the harm is testing it? That is the only way you will know if it is off or not. Gravity does change with elevation but only enough to make a small difference.
There is not a finite answer to that question. You need to get a tension calibrator and tell us how much it is off (high/low)
On a second note, I routinely string my MG Rad OS's 4 lb over max recommended and don't/haven't had issues...... I wouldn't sweat it.
I've been stringing for about 11 years, the only frames I had collapse on me were ones that had pre-existing damage and the owner said, try to string it... if it breaks it breaks, if not, great.
If I understand correctly, the X-2 is as accurate in terms of tension as any other machine. In that case, is the only advantage of more expensive (non-electronic) machines ease of stringing?
Pretty much, more expensive machines save you some time and give you things like linear gripper etc. The tensions are engraved on all gamma dropweights so excluding some manufacturing defect they should be accurate.
No it is not. The X-2 has floating clamps, and as such there would be more drawback as compared to a good set of fixed clamps that are on some quality machines, and that will effect tension results.
There are other differences as well, like the diablo that is on some machines will allow the string to enter the tension jaws at the same angulation each time, and also take some of the tension off the string that the tension jaws are holding, placing less stress on the string, which is very beneficial when stringing nat. gut. I will even wrap the string around the diablo a second time if I have to tension a string a second time for any reason so the tension plates will grab at a different spot, as nat. gut and some thin multi. strings can be more fragile.Then you get the creature features like a good brake that can be very benificial with O port racquets, and other nice features that help make stringing more enjoyable. You basically get what you pay for.
Sums it up -- what a concept!
Buy a portable luggage scale and test a range of tensions. I did on my Klippermate and found it pulled a range of tensions with remarkable accuracy. It set my mind at rest that I wasn't overtensioning on any string being pulled.
Like others have said, the simple answer is: The tensioner should be accurate (at 90 degrees, and very, very close within reasonable angle deviation). The clamps will cause higher amounts of tension loss due to the drawback and/or twisting.
This assumes no manufacturing defects and/or unaccounted for variables (friction in the drop weight, etc)
On a drop weight the error comes out to the cosine of the angle from level and the error is always less tension.
So at +/- 10 degrees off of level (which is a pretty big range) you're only introducing 1.5% of error in tension. With a lockout machine with a stretchy string, you're going to be off by way more than this.
As for the drawback, I'm not convinced this is that big of a deal either. If you pull tension and get that tension around the 180 degrees to the previous string, you'll pull all the drawback back out of the string (ie the clamp will be straight again).
I think there's way more loss in string to string tension pulling crosses and the string naturally stretching after pulling tension to worry about the maybe 2% total loss you'll see from drawback and ever so slightly unlevel tension bar.
As long as you're consistent with your technique, your error will be consistent as well... this goes for a $5k machine or a $100 drop weight.
It depends. How is the gravity at your house? Is it stable, or does it fluctuate?
Well, if he strings on the moon, his string jobs could be out of this world!
Are you asking how much your tension should differ from a lock-out or some other machine that was used on it previously?
Unfortunately, there is no set answer to that question. A few months ago, I got an Alpha Pioneer DC Plus dropweight stringer. My previous stringing professional used a Prince Neos 1000 lock-out machine, and he was very good about keeping it calibrated. Through trial and error, it didn't take me too long to find that my Alpha was stringing 4 lbs. tighter than his.
Separate names with a comma.