So I tested the tension on my Alpha Axis Pro I bought used here from another member. Machine works great, however I have a question about the tension spring. I used a fishing scale I calibrated and checked. When I set the machine to 50 it pulled 55. So I adjusted the tension on the spring to pull 50 when selected. I next tried 55 and it pulled 60, so back to 5 lbs higher than reference. Is this normal? Should I calibrate every string job to make sure I'm pulling the correct tension? Thanks!
Lockout calibration question
- Thread starter Smw1227
- Start date
Fearsome Forehand
Professional
You need to purchase a string tension calibrator calibrator.
There is usually a small screw that you have to adjust to change the tension. Contact Alpha and see if they have manuals for sale. In my experience, their customer service is very good. They are based in TX, DFW area? (Maybe Austin?)
Also, you have to use the initial reading off the fish scale because the string will stretch and the reading drops off considerably.
If all else fails and you think the reading is accurate, you can just factor in the 5 pound difference when you select the tension.
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SwankPeRFection
Hall of Fame
Your scale should be dropping a few pounds after lockout anyway. What does it stabalize down to after 5 seconds max after lockout? What's your scale read at that point?
Also, what are you using to tie the scale to the machine with?
Also, what are you using to tie the scale to the machine with?
Irvin
Talk Tennis Guru
That is not correct. You should adjust the lockout for the initial reading and not what it reads after 5 seconds. Some string lose tension faster than others.
EDIT: FYI http://tt.tennis-warehouse.com/showpost.php?p=5759462&postcount=8
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Irvin
Talk Tennis Guru
It is a little more involved than just that. There is a spring in the lockout that is always pulling for is it applying more tension as the string stretches but not enough to keep it at the reference tension. I will make a video that shows the actual tension loss in a few string and post it here. It will take some time so don't hold your breath.
mikeler
Moderator
I own a Gamma machine but on this one I don't do it Gamma Tech's way. I slow pull all my strings, so I'd rather get the final tension nailed then the initial tension.
I heard it somewhere (here?) that it might take up to 10 sec to reach the reference tension if you care about that.
Is it the same as what you said ..."I slow pull all my strings."?
Is it the same as what you said ..."I slow pull all my strings."?
Irvin
Talk Tennis Guru
I am not sure what you are saying but I think you agree with what Bret said. You adjust your lockout for the initial setting and not 5 seconds later. For instance, if you want your lockout set at 60 lbs you adjust is so the meter reads 60 exactly when the lockout occurs.
I can understand some people do it different though. You think it will take 5 seconds to clamp your string and you want the string at 60 when you clamp it. There is no logic to that though.
yan.v
Rookie
Sounds logical to me, especially if you always use the same string. When someone asks me a certain tension, I want to make sure that they get a tension close to what they asked and not 10% lower.
If you string with a constant pull machine, the tension on the string will be the same as the tension you set your machine at when you clamp the string. I don't see how wanting to replicate that with a crank would be bad if the job is consistent
mikeler
Moderator
I guess I'm being illogical then. ;-) My calibrator pretty much stops losing tension at about the 5 second mark. It "slips" maybe 3 pounds from start to finish during that time. If I calibrate my machine to the 5 second tension, it usually jives well with RacquetTune on most strings. So I'm not listening to Gamma Tech (or the wise Irvin) in this instance and just being a pure crazy stringing rebel!
diredesire
Adjunct Moderator
Agree. The concept of "reference" tension is what should dominate your calibration. If you are calibrating with one specific set of string and are targeting post-lockout tension, you're introducing quite a bit of variability into your system. First off, the LENGTH of the string you use is different than what you string with, so the tension loss will actually be higher in the real-world situation (depending on how you set up your calibrator, of course). Second, all other strings will be "off," and while your reference tension still holds as a reference number, the reference is artificially bad by default. Your reference tension should be calibrated to the lock-out condition, and understanding that you can mimic a constant pull by upping the tension X amount (rule of thumb is 10%, but I encourage people to find their magic number on their own) is the important part. It's the KISS method all over again
Irvin,
As always, thanks for your input. I've learned a lot from your videos. I'm adjusting the tension per Alpha's manual, so I guess adjusting the actual sprig is not the correct terminology. Basically I'm saying when I calibrate, it's pulling 5lbs higher. I am using some Babolat Pro Hurricane I cut out of another racquet as my string in the scale. I was just wondering if it is normal for the machine to read correct at 50lbs and then subsequently be off by 5lbs at another reference tension. Therefore do I then need to recalibrate if I string one racquet at 50 and then the next one at 60? Also, I don't notice any tension drop after I am pulling the string and it locks out. Is it because I'm using previously stretched string? Thanks.
Pure crazy!
It seems to me that the more correct approach would be to calibrate the tensioner in the standard fashion and set it to ~3 lb higher than your goal. But to each his own.
I mostly string poly, and the initial tension drop is less predictable between strings. I thought long and hard about how to work around different tension drops to get the right tension across different string materials, and ended up buying a Wise.
Irvin
Talk Tennis Guru
Sounds logical to me, especially if you always use the same string. When someone asks me a certain tension, I want to make sure that they get a tension close to what they asked and not 10% lower.
If you string with a constant pull machine, the tension on the string will be the same as the tension you set your machine at when you clamp the string. I don't see how wanting to replicate that with a crank would be bad if the job is consistent
So do you think the string stop losing tension after you clamp them? It would be nice if you could find a string that never lost tension but it is not going to happen. Let's go back to the lockout. If you want to give them what they ask for and you're using a lockout why not pull tension get ready to clamp and pull again (just like the CP.) The string has had time to relax and when you pull tension again you have exactly your reference tension.
LOL what you are saying makes sense to many people. Long ago I would have agreed with you 100%. Let's say you have a calibrator and as section of string because the calibrator is in line with the string it means you have to have a shorter section of string. Let's assume you use 1' of string between the calibrator and the tension head (or you can assume any other length.) So your calibrator drops from 63 to 60 in 5 seconds on that 1' section of string. and you have your lockout set to 60 pounds so you assume it is what you want. Now you go to pull 60 lbs of tension on your first main. It goes through the racket and from the racket to the tensioner. Let's assume that is 2' of string. Whatever it is will be long than the shorter section on your tension calibrator. Let's also hope you are using the same string for stringing you have on the calibrator or you going to introduce more error. So is it safe to say the 2' section will have something less than 60 lbs of tension? Come on now be honest.
If you adjust your lockout to lockout when you have exactly 60 pounds it is a no brainer. Pull a string at any length wait 5 seconds and pull again. You have exactly 60 pounds no matter what string you use or how long or short it is.
mikeler
Moderator
That's it. I'm deleting you from my Facebook account! Oh wait, I'm not on FaceBook.
I can get my calibrator to match RacquetTune very closely for my current string of choice with my method. This gives me confidence in my string jobs and since I only string for myself, I'm the only customer that needs to be satisfied.
SwankPeRFection
Hall of Fame
No kidding! I know that. The thing is, I've seen some smaller manufacturers calibrate on the high side in hopes of giving people a closer result in tension with their lockout machines. Do I agree with this? Yes and no. Is this means for someone like you? No. Would it help a novice stringer? Yes.
This goes back to the ******* contest tension thread you trashed by having posts deleted.
SwankPeRFection
Hall of Fame
Mikeler, I find it pointless to try and argue logical points or ideas with Irvin. You and I are on the same page. Irvin in on his own page that's not going to change no matter what.
I think it's safe to say that both of us string a certain way because of what we've seen happen with experience and we've also both probably gotten tired of letting "pro" shop stringers string our sticks with a lockout and getting them back looser than a you know what. But hey, that's OK, if you can't teach an old dog new tricks, simply don't pay them to string your sticks. Do it yourself with perfect repetition and save the money. Then go out and offer a few friends string jobs as a free taste of what quality and attention to detail is. They'll come back and then you charge them a more reasonable price for a better job.
mikeler
Moderator
Irvin has been incredibly helpful to this forum. He is referencing Gamma Tech who certainly knows quite a bit about stringing machines. I believe their method is correct, it is just not the way you and I do it.
diredesire
Adjunct Moderator
Irvin's a pretty good sounding board for stringing theory. I've discussed some interesting points with him in the past, and he's got an interesting perspective that's more right than not. I'm not sure why you decide to lead with an insult...
As far as your "certain way" of stringing, it only shows that you lack the understanding of what "reference" really means. http://en.wikipedia.org/wiki/Accuracy_and_precision
The above article explains accuracy versus precision. What you are mikeler are arguing is accuracy over precision. This is fine. Accuracy is obviously desirable. However, what you should understand is that when a player walks into a pro-shop (lets assume this pro-shop is operated by people who do a good job, and actually care about consistency from job to job), they are actually looking for a string bed stiffness, not a tension. (Besides the point I made above in which you are actually only guaranteeing accuracy based on a limited data set, and it does not apply for 99% of the frames you'll do. If you are offering your services to others, it is irresponsible to your customers to say you're better than a pro-shop. You may be more accurate based on the actual reference tension, simply because you've shifted your cluster of precision, but you're actually doing yourself a disservice, IMO).
Another example: Lets say you lived in state A on the east coast, and your shop A was stringing racquets 10 lbs over what you actually asked for. After 10 years of playing tennis with frames 10 lbs over reference, you moved to the west coast. The west coast stringers string strictly at reference tension. Assume both shops are consistent in their methods, and the string jobs are reproducible.
When you moved, you thought your tension was 50 lbs. You move to the west coast, and suddenly all your 50 lb string jobs are causing balls to fly on you. Who is wrong here? What is wrong here?
The answer is: nothing (sort of). While it is undesirable to have a shop stringing at a tension different from reference, they were providing a consistent, and precise service. When you find a "tension" you like, you've found a string bed stiffness that you have come to expect from your string bed. When you move, you have to find it again. Thus, you choose the reference tension in which the string bed stiffness is reproduced.
As humans, and creatures of "logic" and habit, we want to make sense of the world, and it makes intuitive sense that when we move from machine to machine, stringer to stringer, we should be able to use the same number as on a different machine and a different stringer. It doesn't always work this way (unfortunately).
You mentioned that you should "do it yourself with perfect repetition (and save the money)." Realize, first off, that if someone were to come to you from that pro-shop, they'd probably feel that the strings are a little dead (if they don't already know it's way tighter than the pro-shop's job). Lets say they requested a 65 lb job (due to the pro-shop's "tension loss"). They get tennis elbow, and all their balls are landing really short in the court. The perception of your service will be just as bad (arguably) than the pro shop vs your perception of the work you do. It's all relative, and that's the entire point of having an accurate (not precise!) reference point in which one strings from. When you deviate using a reference tension that is relative to a fake (or perceived) actual tension, you are introducing purposeful inaccuracy to your methods, and it's incorrect. If you understand it's incorrect, that's cool. If you just string for yourself, it's cool.
I'm just saying it's pretty ironic to insult someone saying they can't understand "logic" when you're arguing with someone who is in agreement with an industry member (Irvin --> Gamma tech).
(TL;DR: What makes you assume your notion of what 60 lbs is, is more accurate than someone else's who is allowing their machine (removing human bias) to tension to a set reference? We as consumers can make adjustments, and shouldn't get married to a number and assume our stringers will incorporate some "magic" into their process that works for everyone.)
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Irvin
Talk Tennis Guru
Funny but true stories
^^Two examples of what you're saying. I have a friend that strung with an X2 for over 5 years using the wrong side of the weight to set his tension because the weight was installed wrong and the arrow was on the wrong side. This was done by the previous owner of the X2 that never liked it for some reason so he upgraded. My friend liked his racket strung with poly at 54 lbs while all the friends he strung for complained of the balls were flying on them so he started adding 10 pounds to what ever they asked for and all was well.
Another friend of mine used a drop weight to string his racket at 78 lbs because he "liked them tight," he said. He got tired of stringing so he asked me to string his 90 si racket at 78. After a conversation he insisted on 78 lbs. He could not play with it, the racket had no power. Long story short he never installed the extra weight to string for the higher tensions.
The calibrator that came with my Gamma started sticking at exactly 60 lbs. I found that when I adjusted by stringer I could never get it to pull over 60 and I always calibrated it at 60. Imagine would could have happened if I never tried to see what the stringer did at various tensions like 45, 50, 55, 60, and 65. I now use a digital scale.
You can get the results you want by doing something a different way but that does not make it right. Of course, if it is making you happy it's not wrong either. There is more than one way to get a desired result.
^^Two examples of what you're saying. I have a friend that strung with an X2 for over 5 years using the wrong side of the weight to set his tension because the weight was installed wrong and the arrow was on the wrong side. This was done by the previous owner of the X2 that never liked it for some reason so he upgraded. My friend liked his racket strung with poly at 54 lbs while all the friends he strung for complained of the balls were flying on them so he started adding 10 pounds to what ever they asked for and all was well.
Another friend of mine used a drop weight to string his racket at 78 lbs because he "liked them tight," he said. He got tired of stringing so he asked me to string his 90 si racket at 78. After a conversation he insisted on 78 lbs. He could not play with it, the racket had no power. Long story short he never installed the extra weight to string for the higher tensions.
The calibrator that came with my Gamma started sticking at exactly 60 lbs. I found that when I adjusted by stringer I could never get it to pull over 60 and I always calibrated it at 60. Imagine would could have happened if I never tried to see what the stringer did at various tensions like 45, 50, 55, 60, and 65. I now use a digital scale.
You can get the results you want by doing something a different way but that does not make it right. Of course, if it is making you happy it's not wrong either. There is more than one way to get a desired result.
SwankPeRFection
Hall of Fame
I don't think we're arguing about having misinstalled machines or used by people who don't know what they should be seeing from these machines. When I discuss all my points, you should know that I'm not going to throw in the variable of an idiot user. The reason for this is that 9 times out of 10, the OP doesn't indicate that they don't have a properly working machine. Perhaps everyone opening up a basic question thread should post a picture of their machine they're having issues with, but generally speaking, nobody ever starts a thread with "I'm checking the calibration on my machine and it seems to be way off... as in it reads 0. Oh, you mean I have to crank it?" Come on... you sometimes can't account for stupid.
Machines come with instruction books. If they didn't the user should have done enough due dilligence to watch as many videos as necessary or read up as much as possible about stringing and stringing machines before getting involved with it. If they didn't and are making some other mistake and not even mentioning the possibility of that being a problem when they start their post. I guess what I'm saying is that if I can take the time to make sure all my stuff was put together properly and it's functioning properly, everyone else should at least do the same for their own benefit.
As for diredesire's post about people walking into a pro shop asking for stringbed stiffness instead of tension, I'm not sure I agree with that. I've had bad experiences when I went into shops and asked their stringers to get me something at 58lbs. One gave me a loose job and the other gave me one of what I expected to feel from a 58lbs job (i.e. I used to play with the same racquet and strings and strung it at 58 from a reliable stringer and I know what it should feel like). When you give it to me and it feels looser, there's a problem with what you're doing. Eventually, I specifically asked for just one of their stringers to string my stuff no matter what. Each time I got my sticks back, they were exactly how I wanted them and the machine was set to 58 as I asked them to and I visually verified it and watched him complete a job. I then asked the other stringer to do the same while watching them both on the same machine, same racquet model, same string, same tension and that stringer turned out a loose playing racquet. Both me and the two stringers played with both examples and the stringer that was doing a better job could tell immediately that the other racquet was looser, the other stringer could not tell as easily. I then had the good stringer cut out the strings and restring it and it came out exactly as his first one... perfectly playable and at 58 as requested. When I started stringing my own racquets, I took my time doing the work and they all come out exactly the same and they feel exactly like the good stringer's jobs did. Obviously one of those stringers was botching their technique (faster/rushed, not pulling all the slack out, etc.).
As time passed, I eventually started experimenting with looser tensions and settled lower than the 58 original setting I used to play with, but some of that is also due to string type change which caused the racquets not to play as well at the higher tensions with the current setup, nothing out of the ordinary when you're changing strings. But the end results have not changed... each one comes off the machine feeling the same as the other and each one has the same progression of feel change the longer you play with it on court. It's an expected result and that's what I'm after. Very few stringers have been able to give me what I want when I ask them to.... and my requests are NEVER different. If I ask one stringer for 58 on a lockout and another at 58 on a lockout, I expect the same damn results if I'm going to pay them. If they can't do that, it's not worth it to me to pay for such variances between string jobs with I'm keeping everything else the same (string, tension, racquet).
Machines come with instruction books. If they didn't the user should have done enough due dilligence to watch as many videos as necessary or read up as much as possible about stringing and stringing machines before getting involved with it. If they didn't and are making some other mistake and not even mentioning the possibility of that being a problem when they start their post. I guess what I'm saying is that if I can take the time to make sure all my stuff was put together properly and it's functioning properly, everyone else should at least do the same for their own benefit.
As for diredesire's post about people walking into a pro shop asking for stringbed stiffness instead of tension, I'm not sure I agree with that. I've had bad experiences when I went into shops and asked their stringers to get me something at 58lbs. One gave me a loose job and the other gave me one of what I expected to feel from a 58lbs job (i.e. I used to play with the same racquet and strings and strung it at 58 from a reliable stringer and I know what it should feel like). When you give it to me and it feels looser, there's a problem with what you're doing. Eventually, I specifically asked for just one of their stringers to string my stuff no matter what. Each time I got my sticks back, they were exactly how I wanted them and the machine was set to 58 as I asked them to and I visually verified it and watched him complete a job. I then asked the other stringer to do the same while watching them both on the same machine, same racquet model, same string, same tension and that stringer turned out a loose playing racquet. Both me and the two stringers played with both examples and the stringer that was doing a better job could tell immediately that the other racquet was looser, the other stringer could not tell as easily. I then had the good stringer cut out the strings and restring it and it came out exactly as his first one... perfectly playable and at 58 as requested. When I started stringing my own racquets, I took my time doing the work and they all come out exactly the same and they feel exactly like the good stringer's jobs did. Obviously one of those stringers was botching their technique (faster/rushed, not pulling all the slack out, etc.).
As time passed, I eventually started experimenting with looser tensions and settled lower than the 58 original setting I used to play with, but some of that is also due to string type change which caused the racquets not to play as well at the higher tensions with the current setup, nothing out of the ordinary when you're changing strings. But the end results have not changed... each one comes off the machine feeling the same as the other and each one has the same progression of feel change the longer you play with it on court. It's an expected result and that's what I'm after. Very few stringers have been able to give me what I want when I ask them to.... and my requests are NEVER different. If I ask one stringer for 58 on a lockout and another at 58 on a lockout, I expect the same damn results if I'm going to pay them. If they can't do that, it's not worth it to me to pay for such variances between string jobs with I'm keeping everything else the same (string, tension, racquet).
Irvin
Talk Tennis Guru
Let go back to the the OP's initial question because we are way off track.
I really don't understand what the OP is saying. I assume when he pulls 55 it locks out at 60. Hopefully it does not come to rest at 60 and start at an even higher number. Maybe if he waits 10 seconds it reads 55 instead of the initial 60. If he waits a reasonable amount of time and it does drop to 55 is his machine adjusted properly or not? I don't think so, if he sets his machine to 55 and it pulls something higher than 55 it is out of adjustment and needs to be calibrated.
The OP is new and is asking what is normal. I assume he just doesn't know or he wouldn't have asked the question.
diredesire
Adjunct Moderator
This is true, and valid, but doesn't disprove the argument. It is all linking back to reference tension, and accuracy and precision. Should the operators have known better/could they have known better with minimal effort? Sure, but the fact is someone was requesting a "tension" that way waaaaaay off the actual tension, and achieved what (s)he was looking for.
Sounds like you're describing to me exactly what I'm describing
A) I made the above points with the assumption that all stringers involved were competent AND consistent (precise). Your experience (mine too) doesn't reflect this assumption. This is NOT part of the discussion when it relates to tension and stringbed stiffness. Human variability is actually an argument in favor of using an actual lockout tension instead of a higher-than-actual-to-compensate-for-string-variance. Lets simplify your situation and say that the reason the "crappy" stringer was different from the other stringer in only crank speed. This can (and generally does) yield lower tensions. Great!
What if that guy was the ONLY stringer, but he was extremely consistent at it? Lets not cloud the point of discussion by adding in the variable of different stringers at the pro shop (I am well aware of this being possible, and I agree with you --> it's not desirable, but it's also not the point).
You said "When you give it to me and it feels looser, there's a problem with what you're doing." This is exactly what I mean by reference tension in relation to string bed stiffness. You asked for 58 lbs. Something felt off about the job. What makes your perception of what 58 lbs is more valid than someone else's? (entertain me here, as this is hypothetical...) What if you had been mis-strung all your life, and you had always used a stringer that strung +10 lbs by no fault of their own. Lets say they had a calibrator that had its spring mis-adjusted. Even though they went through their due diligence, their equipment was off. You had come to some intuitive/"feel" that correlated to 58 lbs. Lets say the crappy stringer was actually stringing you at 58 lbs, but it feels way off. This IS reference tension in relation to stringbed stiffness. The reason you always see me use "reference" in conjunction with "in relation (to)" is because that's the entire point of "reference."
While your anecdote definitely illustrates what a big problem of "big box" stringing is, it doesn't really impact the reasoning behind why one should calibrate to "reality."
"I took my time doing the work and they all come out exactly the same and they feel exactly like the good stringer's jobs did." (I'd like to point out that you subjectively deemed the "good" stringer as good, it's kind of circular logic to say that you're good because you're matching).
I'd go as far as to argue that the "bad" stringer, in this case, is not necessarily bad! If he is precise, and extremely consistent, you just bump your reference tension to adjust. So what if you had to use a different number? You're after the feel, not the tension.
(As an aside/With that said: tennis is a very mental game, and someone having to suddenly "jump" 8 lbs [arbitrary number] can affect someone's game, I happily admit that. From a stringing theory standpoint, consistency is king, IMHO).
Sure, I'll buy it. You want to pay for something that is consistent with your expectations. All I'm saying is that your number that you equate to an expected feeling on a stringbed is actually very arbitrary. NO ONE strings at "reference" tension. There's always deviation from the absolute accuracy point. It's all about precision.
You're right:
Answer below is calibration technique for a NEOS, but in short:
How did you calibrate the fishing scale? Is it guaranteed accurate at the weights you're interested in? Obviously it's nice to have a second calibrator (standard spring plunger calibrator) for a sanity check. Short answer is: Calibrate at a known tension (I like to use 60 lbs) and do spot checks for linearity and reality checks. I don't know the full calibration procedure for the Axis series, but below might help if it's not a simple offset issue.
Short answer though, is no, you should be calibrating at a known point, and things should be pretty darn close to linear from that point.
Answer said:
COPEY
Hall of Fame
"Sounds like you're describing to me exactly what I'm describing."
When I read Swank's reply those were my exact thoughts, but I don't have your patience. I could quote a statement from Swank's last post which represents another interesting (yet ironic) twist, but it would serve little purpose and probably incite more insults...and we certainly don't need any more of that.
Anyway, great post, diredesire!
When I read Swank's reply those were my exact thoughts, but I don't have your patience. I could quote a statement from Swank's last post which represents another interesting (yet ironic) twist, but it would serve little purpose and probably incite more insults...and we certainly don't need any more of that.
Anyway, great post, diredesire!
diredesire
Adjunct Moderator
Like I said, I'm cool with it if you know what you're doing, and understand the difference. Swank actually recommends stringing for others in this thread, so that's a little different, but that's an entirely separate thread. In the end, I assume we're all free to make our own decisions, and I won't think any less of someone if they do something different from me. As long as we're all willing to remain open and hash out why, that's cool. I'm willing to admit it if/when I'm wrong, and I'm willing to learn things from even the newest of stringers.
I'd also note that the difference in the final product is minor, anyways, so I'm not going to lose any sleep over it if people don't take my advice
The main point is: If you (and Swank) somehow lost your ability to string, and were left at the mercy of someone else, it's likely you'd actually have to increase the number you tell someone to string your frames at compared to the number you set on your dials (ta-da! that's the actual concept of reference tension. I spell it out a million different ways, but it's actually a pretty foreign concept to new stringers (IMO)).This is the answer I was seeking. If I calibrate to 50 (for example), does that mean the machine should be calibrated for all tensions within a range of "x" to "y"? As for my calibration tools and technique, I took a 50 lb weight and put it on a digital scale to test it's weight. I confirmed it's 50 on the dot, then tested the weight hanging from the fish scale (plunger spring type). Again it measured 50 lbs. Then I put the scale in the machine and pulled tension. It measured 55lb. So I followed the machine manual for adjusting the tension for the crank. Now it reads 50lbs @ lockout. So I thought, let's try 55lbs. The resulting pull showed closer to 60. So it reads 50 when set to 50...but 60 when set to 55. Does this answer your questions? Thanks for the input and assistance.
Irvin
Talk Tennis Guru
There was a post started by 'sstchur' some time ago where he had a problem like the one you described. 'Gamma Tech' (Bret) at the time sent him a detailed procedure for adjusting his GAMMA lockout maybe he still has it or maybe you get a copy from the new 'Gamma Tech.' I know it is not your machine but may the process is you see it will help you figure out how it is done. It would be best if you could get a procedure from Alpha. Give them a call maybe they have one for your machine.
If you're interested here is the thread:
http://tt.tennis-warehouse.com/showthread.php?t=398829
If you can't get it here is what I am guess is the problem. Maybe you can figure it out from here. If not give us a shout back and we will try to help. The lockout occurs when the gripper is pulled up high enough so a catch slips off a lever that engages the brake. Maybe the whole gripper assembly is off its own correct angle to start with and as you go up it tension it has to go higher and higher to slip off. You could easily check by lowering tension and see if it goes lower.
Good luck I am sure there is a way to fix it. If you run into problems let us know.
If you're interested here is the thread:
http://tt.tennis-warehouse.com/showthread.php?t=398829
If you can't get it here is what I am guess is the problem. Maybe you can figure it out from here. If not give us a shout back and we will try to help. The lockout occurs when the gripper is pulled up high enough so a catch slips off a lever that engages the brake. Maybe the whole gripper assembly is off its own correct angle to start with and as you go up it tension it has to go higher and higher to slip off. You could easily check by lowering tension and see if it goes lower.
Good luck I am sure there is a way to fix it. If you run into problems let us know.
GlenK
Professional
I use the slow pull button on everything except gut. If you play with it, try slow pull, then fast pull the next job and see if you feel a difference. I swear it feels a bit more crisp for me using the "fast" setting.
SwankPeRFection
Hall of Fame
I actually string for others as well and what I do is consult the client before I string for them. They usually come in and say that they've had something strung at a certain weight and they like it there with their specific string, racquet, etc. I ask them if they remember what it was strung on and I also ask them where they got it strung at. If I know the place that did it, I usually know the types of jobs they get there and can correct accordingly. Then I do one string job for them to the closest educated tension as I know they'll be happy with. So far, I've been able to be off by no more than 2-4 lbs (4 at the most) and most times I'm dead on. The client gets full disclosure of what the racquet was strung at AFTER they come back from a playtest of a couple of sessions. That way, they don't have a placebo affect in their heads of (oh, my stuff was strung at a different tension). When they come back, they indicate what it felt like in reference to what they're used to. I'd say most of the time, they're happy because it felt the same. I then tell them what it was strung at and explain why... I belive they should understand why it was done that way so that if they ever go somewhere else, they can keep in mind that for a lockout they should has for x and for other types of machines they should ask for x. In the end they're very happy and come back because they like the super clean work and they like the OEM fit and finish of my grip jobs as well. Did I mention how much I hate it when you pay someone for a grip or overgrip install and the job looks like crap? Heck, you see it on tour all the time too... some people don't care what the finishing tape looks like, etc. When I grip your racquet, you get an OEM finish... because that's how I grip my racquets and I think it shows quality workmanship. People usually look at my sticks and like what they see... they always say, hey, can you install my grips as cleanly as you do your? Sure...
Now, to some other points for the other guys here. Yes, in a pro's hands, machines should be calibrated to exactly what you need and most times, that pro can change the calibration to fit them. However, what I've noticed is that on some machines that are "popular" for the novice home user, the manufacturers have built in some leeway in terms of tension exactness so that the noobs can get the results they expect from something they haven't even read the manual to use. Think of this as the stringer's grading curve if you will. I've seen quite a few machines that are tight when they're fresh out of the box due to stiff springs that eventually loosen up to the exact setting after about 3-5 string jobs. Chances are good that if you had recalibrated this machine to be exact out of the box, you'd now be loose after only a few jobs and have to redo the work. Would it benefit a pro who's done this for years and calibrates his stuff each week (depending on volume)? Sure. Would it benefit the noob who just bought his machine for home stringing and won't calibrate it for months and strings a few times a month? Even more so I believe.
That's the principal I was trying to get you guys to understand. As long as we can see eye to eye on that, we're all good.
SwankPeRFection
Hall of Fame
If this is a new machine I'm willing to bet that it's either a stiff spring issue or a spring issue period. This is why I don't like lockouts. In order for it to be dead on, it must have a perfectly leanear spring rate and generally speaking... most stuff made for something as non-critical as a stringer, isn't going to be this precise. I would play around with your calibration settings and check your reference tesions in 5 increments after each set.
Calibrate to 50 and pull 50. If it locks out, then pull 55, 60, 65, 70 and see if the difference in measured tension is the same at all those pulls without calibrating at each point. If it's still off by 5 at each one, then take the 60 pull and calibrate for 60. Once it locks out at 60 for a 60 pull, go back and pull 50, 55 and 65, 70 and see where you're at. What you're trying to figure out is what's throwing this off and my bet is that it's a tension spring issue (because it's too new or just a poorly tempered one). The bottom line is, if you can get the pulled tension to be within +/-2 to 3 lbs of what you set the machine to, go with that for a few stringjobs and then recheck the machine afterwards. Give it some time to work the newness out of it and see if things don't settle down more. If they don't, then you have a low quality part somewhere... or wore a low quality machine, but I have a feeling that if you call the manufactuere, they'll probably give you a story of "Well, if it's off by +/-5lbs, that's within norm on a manual lockout... if you want something more precise, get a digital one instead." It woudn't be the first time I've seen this happen.
The machine was purchased used from another member here who no longer plays. According to him, about 50 racquets were done by him. I strung a racquet for the first time last night. Set 50 as my tension and racquet tune said I was fairly close as it read 48 after I was done. I'll try again with another racquet say at 55 next time and see how it comes out. Thanks guys!
diredesire
Adjunct Moderator
Consulting (and educating) your clients is good. I wouldn't approach it the same way, but asking the right questions (as you appear to be doing) and explaining the differences is great. What you're doing is exactly what I'm talking about, though. You're setting a customer's expectations and adjusting the actual tension, because of what their reference is. You're adjusting string bed stiffness!
I'm going to skip the grip comments, because they're not really relevant to the discussion. I appreciate attention to detail, though.
Now, to some other points for the other guys here. Yes, in a pro's hands, machines should be calibrated to exactly what you need and most times, that pro can change the calibration to fit them. However, what I've noticed is that on some machines that are "popular" for the novice home user, the manufacturers have built in some leeway in terms of tension exactness so that the noobs can get the results they expect from something they haven't even read the manual to use. Think of this as the stringer's grading curve if you will. I've seen quite a few machines that are tight when they're fresh out of the box due to stiff springs that eventually loosen up to the exact setting after about 3-5 string jobs. Chances are good that if you had recalibrated this machine to be exact out of the box, you'd now be loose after only a few jobs and have to redo the work. Would it benefit a pro who's done this for years and calibrates his stuff each week (depending on volume)? Sure. Would it benefit the noob who just bought his machine for home stringing and won't calibrate it for months and strings a few times a month? Even more so I believe.
That's the principal I was trying to get you guys to understand. As long as we can see eye to eye on that, we're all good.
I'm going to be a little blunt here, but... can you name an example? It seems to be a lot of hand-wavy posturing here. I'd like to hear more about the mechanisms with "built in" leeway. What does this even mean?
The machine is actually pulling higher until it "breaks in?" Even if you really DO have anectodal reports of this, I have to urge a "newb" as you put it to largely ignore this unless it has been shown by design, or by measurements. You mentioned a pro can "change the calibration to fit them." I'm not sure what you're referring to, but if you're saying pro level stringers are making piece-wise adjustments and bumping tension, I have to strongly disagree.
Anyways, you've thrown in some interesting terminology ("Stringer's grading curve"), but I'm not convinced any of this is true beyond an opinion. I will be happy to agree that it is possible that springs can fatigue and change over time, but I will disagree that they are designed to not be linear. That's the entire purpose of calibration to begin with (obviously we're talking about cranks, and maybe low-end electrics that actually use springs as a reference). It's many more times likely that an inexperienced user will have very wildly varying crank rates and will prematurely activate a lockout condition without strings properly elongating. This is operator error, and my comments assume competent operators (this isn't something I can control).
As far as recalibrating a machine straight out of the box... --> They are calibrated at factory. Why would you ever want to? If a machine is off (or as you say, designed to be off to account for relaxation/break in), I'd first question your calibrating equipment before questioning the factory. Most home stringers use wildly cheap/inaccurate/spring reference devices to calibrate... well, other spring reference devices. We aren't using load cells/strain gauges, so our calibration techniques are at best sanity checks and confirmations.
I hope you don't feel like I'm singling you out/picking on you, but you have strong opinions, and no data to back it up. I'm not asking you to do a science experiment to prove me wrong, but assuming a stringing machine is non-critical, and that a proven lockout mechanism is under-designed is an insult to the engineers. Furthermore, if it was under-designed, there would have been a significant change to the design over the years. The fact that manufacturing efforts/R&D is actually cheaper in terms of mass production now than it was, say, 30 years ago only reinforces that fact. You make a bold claim, I just ask that you prove some reasoning behind it.
As far as linearity, again, this is much more likely to be affected by the operator rather than the lockout mechanism itself.
As for OP: I'd contact Mark at Alpha, he will likely get you sorted out much more completely than we're able to in this (now way derailed) thread. Personal apologies for contributing to the majority of this derail
Edit: His e-mail is mark (at) alphasports.com
Don't hesitate to contact him, he's truly a delight to work with.
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SwankPeRFection
Hall of Fame
I second the "talk to Mark at Alpha" suggestion. Whatever you do, don't talk to Greg. lol His blood sugar levels seem to be low every time he answers the phone. :lol:
Anyway, to address some desire's points above, no machine is perfect from the factory. I like Alpha, but it's certainly no perfect manufacturer. That being said, I wouldn't hessitate to buy aother Alpha before a Gamma or other cost effective machine. With that understood, anything from spring harshness or smoothness of the lockout mechanism can cause something to pull at a tighter tension until it wears in. Seeing as this machine has had 50 or so racquets done on it, I'm pretty sure it's well broken in, so the tension variances you're seeing is either a bad scale you're using or something the machine is doing.
A lockout's mechanism is very similar to a trigger/sear mechanism on a gun. The two engaging surfaces which are designed to slip on each other until one slips off the other to trigger some kind of reaction needs a certain amount of roughness to maintain the correct tension needed to disengage it. If you smoother it out, it takes less lbs to drag the two surfaces on each other, the converse is true that if the two surfaces are rough, more lbs is needed to trigger the mechanism open. That being said, these metal pieces are mass produced and while they are close, they aren't perfect. Whatever small variance there is in these parts are usually offset by tightening the calibration nuts on the spring guage/adjuster. Couple this with two springs never beeing created equal due to poor qc or other factors and this is why calibration is needed. Whenever dealing with mechanical components, it's never an exact science. These variables is usually why I prefer a drop weight or digital stringer instead. Granted the digital one needs calibration also, but it doesn't have things like changing spring rates, etc. to deal with over time).
Anyway, to address some desire's points above, no machine is perfect from the factory. I like Alpha, but it's certainly no perfect manufacturer. That being said, I wouldn't hessitate to buy aother Alpha before a Gamma or other cost effective machine. With that understood, anything from spring harshness or smoothness of the lockout mechanism can cause something to pull at a tighter tension until it wears in. Seeing as this machine has had 50 or so racquets done on it, I'm pretty sure it's well broken in, so the tension variances you're seeing is either a bad scale you're using or something the machine is doing.
A lockout's mechanism is very similar to a trigger/sear mechanism on a gun. The two engaging surfaces which are designed to slip on each other until one slips off the other to trigger some kind of reaction needs a certain amount of roughness to maintain the correct tension needed to disengage it. If you smoother it out, it takes less lbs to drag the two surfaces on each other, the converse is true that if the two surfaces are rough, more lbs is needed to trigger the mechanism open. That being said, these metal pieces are mass produced and while they are close, they aren't perfect. Whatever small variance there is in these parts are usually offset by tightening the calibration nuts on the spring guage/adjuster. Couple this with two springs never beeing created equal due to poor qc or other factors and this is why calibration is needed. Whenever dealing with mechanical components, it's never an exact science. These variables is usually why I prefer a drop weight or digital stringer instead. Granted the digital one needs calibration also, but it doesn't have things like changing spring rates, etc. to deal with over time).
i know for sure that my combo 910 (say what you want about eagnas...) would pull higher tension when then tensioner was further out on the bar/track than when it was closer to the frame at lockout.
don't know why, maybe the "eagnas" effect but it's essentially the same mechanism as the higher end machines, design-wise.
i learned the sweet spot and was able to string "accurately" but when calibrating (checking) i could always reproduce this phenomenon.
don't know why, maybe the "eagnas" effect but it's essentially the same mechanism as the higher end machines, design-wise.
i learned the sweet spot and was able to string "accurately" but when calibrating (checking) i could always reproduce this phenomenon.
yan.v
Rookie
Yes, the string keeps elongating even when clamped. The difference is, if someone asks you 50lbs and you calibrated your machine for initial reading, the tension will be close to 45 when you're done. If you calibrated your machine for the reading after ~5-10 seconds, your tension will be closer to 50lbs when you're done. The only argument that makes sense against this method is if you use different strings with different tension loss.
Pulling the string twice would yield better results, but it also takes way more time.
Irvin
Talk Tennis Guru
Pardon me but I don't buy that logic
Very many people see it that way but it is not correct. If the string kept getting longer I would have loops of string on the outside of my frame. It does not get long it changes. A string when you pull it resists change and will only stretch out when enough force is applied. Depending on how much force is applied and the amount of resistance to change I will have tension in the string. The more the stretch, the more the resistance, and the more the tension. When you clamp the string the stretch does not change (in a perfect world) but the resistance to the stretch goes down as the string relaxes its resistance and therefore the tension drops.
Now let's look at a calibrator. When I got my gamma machine a calibrator came with it with two looks of string on each end. Now the spring inside the calibrator is never going to change or it would not be worth having. Just think you use it one and it reads 60 next time 58 next time 56. Not good so the only thing that is relaxing is the strings on each end of the calibrator. So you have two lengths of doubled over string with a 6" section if the middle with something that does not stretch (in only measure the force applied.) So you let the string settle for a given amount of time and that is where you calibrate your stringer when set to 60 pounds.
Now you tension a string in a racket with a single string. Because the string is not doubled over it will stretch more after lockout. And that single string is longer. Because the string is longer it will stretch more after lockout. So when you set your machine to 60 lbs if pull more than 60 pounds and your don't know how much more. And because your string is losing more tension for the reasons stated above you have no idea of what your tension is.
EDIT: And unless the string your are stringing is the same as the string tied to the end of you're adding more variables into the equation. It only makes sense to me to control the pulling force and the only way you can identify that is to adjust the lockout for the force on the lockout's dial when it locks.
Very many people see it that way but it is not correct. If the string kept getting longer I would have loops of string on the outside of my frame. It does not get long it changes. A string when you pull it resists change and will only stretch out when enough force is applied. Depending on how much force is applied and the amount of resistance to change I will have tension in the string. The more the stretch, the more the resistance, and the more the tension. When you clamp the string the stretch does not change (in a perfect world) but the resistance to the stretch goes down as the string relaxes its resistance and therefore the tension drops.
Now let's look at a calibrator. When I got my gamma machine a calibrator came with it with two looks of string on each end. Now the spring inside the calibrator is never going to change or it would not be worth having. Just think you use it one and it reads 60 next time 58 next time 56. Not good so the only thing that is relaxing is the strings on each end of the calibrator. So you have two lengths of doubled over string with a 6" section if the middle with something that does not stretch (in only measure the force applied.) So you let the string settle for a given amount of time and that is where you calibrate your stringer when set to 60 pounds.
Now you tension a string in a racket with a single string. Because the string is not doubled over it will stretch more after lockout. And that single string is longer. Because the string is longer it will stretch more after lockout. So when you set your machine to 60 lbs if pull more than 60 pounds and your don't know how much more. And because your string is losing more tension for the reasons stated above you have no idea of what your tension is.
EDIT: And unless the string your are stringing is the same as the string tied to the end of you're adding more variables into the equation. It only makes sense to me to control the pulling force and the only way you can identify that is to adjust the lockout for the force on the lockout's dial when it locks.
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Irvin
Talk Tennis Guru
I think you're correct. But I also think debate on techniques is good for any one who is interested in the subject or joining. IMHO, out of the debate many people will form their own opinions as to which way is best for them.
Also I resent being call an ex-spurt. Isn't that a has been drip under pressure? LOL
It varies by the type of string. If you're stringing a soft poly on your X-2, you'll probably get the bar level and watch it slowly drop down for a few seconds, requiring further adjustment before the bar stays level. That doesn't happen nearly as dramatically with synthetic gut or multifilament strings.
With a crank, you can wait a few seconds (longer for string that relaxes more) and pull a second time. Or you can pull a higher tension once assuming the string will relax down to your target tension.
Irvin
Talk Tennis Guru
A crank never adjust for anything once it locks out.
Take your drop weight you tension a string for 10 second to get to 60 lbs of tension. That means your stringer is pulling for 10 seconds and the stringer continues to stretch and as it continues to stretch the arm falls.
Once you are done and the string is clamped it does not matter how the string was stretched. What is important is a consistent time and force force. If one time your drop weight reaches horizontal in 5 seconds and another time it reaches horizontal in 10 seconds the string will be stretched more or less depending on how long the string was stretched. different times mean different lengths. Different lengths mean different tension from one string to the next.
In a lockout I can pull the string wait 10 seconds and pull the string again wight the exact same force. If the time and force are the same the stretch is the same string after string.
We are talking about very small differences here and when all is said and done it does not matter if you have small differences on different string as the string bed stiffness is really all that matters. It may take a very experienced player with exceptional feel to tell the differences.
Take your drop weight you tension a string for 10 second to get to 60 lbs of tension. That means your stringer is pulling for 10 seconds and the stringer continues to stretch and as it continues to stretch the arm falls.
Once you are done and the string is clamped it does not matter how the string was stretched. What is important is a consistent time and force force. If one time your drop weight reaches horizontal in 5 seconds and another time it reaches horizontal in 10 seconds the string will be stretched more or less depending on how long the string was stretched. different times mean different lengths. Different lengths mean different tension from one string to the next.
In a lockout I can pull the string wait 10 seconds and pull the string again wight the exact same force. If the time and force are the same the stretch is the same string after string.
We are talking about very small differences here and when all is said and done it does not matter if you have small differences on different string as the string bed stiffness is really all that matters. It may take a very experienced player with exceptional feel to tell the differences.
diredesire
Adjunct Moderator
In order to match the stringbed stiffness of, say, a CP machine.
Out of context, though, if your "target tension" was really 60 lb, and you pulled at 65 to hit your "target tension," your desired stringbed stiffness was achieved at 65. You should just string at 65 because that's what you want.
Reference tension. If you bounce back and forth between stringers/machines, it's good to know the rule of thumb to get what you want, but saying "target tension" can be misleading.
This is close, but not completely true, since different parts of the racquet have different lengths of string. The tension won't be the same, but...
...you nailed it here.
I agree, and I try to provide context to my customers. Many of them have a history of getting their racquets restrung on a lockout machine and all they know is that 58lb feels right.
For the way I intended to use the terms, target tension is where the string settles to after it's pulled by the tension head. For a constant pull machine, target and reference tension should be the same. I hope I'm not confusing anyone, but when I'm thinking about lockouts, it's easiest for me to differentiate between reference tension and the actual tension that I can expect in each string when it's clamped.
diredesire
Adjunct Moderator
The only problem I have with this is that by the time the player is actually hitting with the frame, the tension has dropped, and that's the actual string bed stiffness they have grown to expect when they drop off a frame with a stringer, and pick it up at a later time (sometimes days!). This could be a ~10% drop in tension, could be more, could be less. I think it's more realistic to refer to it as a desired string bed stiffness target rather than a tension.
Irvin
Talk Tennis Guru
Now you are getting more into the benefits of a self centering turntable. The 6004 does have a self centering turn table. This means the distance from the top and bottom of the racket and the pivot point on the turntable is always the same and the racket rotates around the pivot. Because the starting location of the tensioner is fixed (always against the stop) the distance from the tensioner to the pivot point is always the same. The increased distance for the longest string to the shortest string is 1/2 the length of the string in the racket.
Therefore if I take a mid size racket that is 13" top to bottom (head only outside measurement) and 10" wide there is a difference of 3" The distance to from the pivot point to the outside of the string is therefore 5" to 6.5" or the longest string is 1.5 inches longer than the shortest if I measure it from the gripper to the far end of the racket. The difference gradually changes from the center of the racket out on all strings.
Now let's take a look at a non-self centering turntable. And to even make things worse let's string up a Prince racket with O ports. The USRSA published a tip on how to mount these rackets so the turntable pivot point is located closer to the head of the racket. When you pull cross strings on and O Port if the port is above the turn table's pivot point the string wants to rest in the top portion of the O Port and that is not good so you use something to get the string in the bottom of the port (boomerang, sharpie cap, S hook, brake, or whatever.) By moving the pivot point to the top of the racket the problem occurs on fewer cross because once you get past the pivot point the string come to rest in the bottom portion of the O Port. Let's say you mount the racket it the pivot point is 2" closer to the head. Now looking at a racket 13" from head to throat the pivot point is 4.5" from the head and 8.5" from the throat. That four inch difference means you will have a tension on adjacent string because one is 4" farther from the tensioner.
But these again are small differences. All I am saying is very small differences. But all the little things add up to big things after a while.
Let's look at gravity on a drop weight. If I string at sea level on a pole or sea level on the equator it doesn't matter much because we are talking about minutes differences. But if I am using a drop weight with a 5 lb weight I have to have some lever advantage to string at 60 lbs. 12 times - That means the small difference in weight is now 12 times greater.
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