Help with Centrix Stringing Machine

[Hornet83]

Hi all

Yesterday I bought a used stringer, it didn't come with a manual and the seller couldn't help me either.

I have a serious doubt and it may sound a bit noobish but on the second picture is the machine pulling 18kg or 24kg of tension?

Thank you.

[Irvin]

Assuming your turntable is on the left you are pulling 18 kg

[Hornet83]

ok thank you Irvin, next week I will get a reel and will try my first stringjob.

cheers

[shamaho]

Looks exactly like the tyger brand, the stickers on the weight (1st pict) should be facing the other way, and yes youd be pulling 18kg

[ART ART]

I know a 2 persons that have that centrix machine, just like your's, one with fixed clamps and another with floating clamps.

I have already try it.
If you can get a calibrator to measure the tension, you will see ... 24

Or,
...Just try it, and compare the stiffness of the stringbed with another machine at the same tension.

I guess that dropweight is heavier than others, used in another machines/brands.

If you and others could measure the weight of the dropweights in they'r machines, we could check it out ... anyone?

[Hornet83]

thank you for your answers

I'm trying to get somewhere without buying a calibrator.

I don't have a precise weight scale, I've weighted the dropweight and it is around 2,2kg, the arm itself is around 0,48kg. I've mesured the lenght o the arm and the diameter of the pulley and by that I know the mass center of the arm. After some simple math I found that just the bar pulls 4,2kg of tension.

the dropweight mesures 7,82cm, and I've mesured the lenght of the scale at 25kg, so the mass center of the weight is that length plus or minus 7,82cm/2 corresponding reading on the right or left side of the weight.

Conclusion is if I try to pull 25kg on the scale, if I read 25kg on the right side the weight I'll be pulling 20,4
kg, if I read 25 on the left side of the weight I will be pulling 26,7
kg.

As I said I don't have a precision weight scale so there is a error on my calculations, if anyone has the time to take a look and find that I've done something wrong please let me know

[ART ART]

That math, shows that the correct reading for this machine is on the right side of the weight. I agree with that.

[Hornet83]

Originally Posted by ART ART

That math, shows that the correct reading for this machine is on the right side of the weight. I agree with that.

From the math the correct reading on the second picture is around 18/19kg.

But if you know this particular machine and you are sure that I should be reading on the right side I will pull 25kg (or 19) and will get the other racquet strung somewhere else and compare them side by side, I think it will be quite noticeble if one racquet has more 6kg than the other.

On a side note, if I make a reading on the right side of the weight the number in the scale is hidden under the weight, if I read on the left side the number is visible, this may also be a clue that I should read on the left? Wish I had a more trustable weight scale to know for sure.

Thank you all
Cheers

[ART ART]

In this 2 machines I know, they use to strung using the right side.
I once strung one or two rackets with the floating clamps version, and the results ware very good as I can remember.

Do the experiment with 2 rackets(same mold), same string and tension, using Centrix and another machine.

Let us know about it...

[Irvin]

Originally Posted by ART ART

That math, shows that the correct reading for this machine is on the right side of the weight. I agree with that.

OP should get a calibrator and test to make sure.

EDIT:

[shamaho]

The image Irvin posted has the instruction: "Until the face closest to the string gripper is indexed with..." that would be the left side of the weight.

Also, I double checked in the instruction manual from Tyger machines (I'd bet they're from the same manufacturer) also states clearly that's the left side of the weight is pointing the desired tension.

HOWEVER... I also did find (subjectively) that the tension coming out of my string jobs felt way more tight than what I was used from my stringer (also using a drop-weight machine), but since I'm a noob, I'll put that down to my poor technique (for the time being)...

Originally Posted by Irvin

OP should get a calibrator and test to make sure.

EDIT:

[Hornet83]

I'm convinced I must do the reading on the left side of the weight.

Thank you all for your help and comments, I will report back once I finish my first stringjob!!

Cheers

[ART ART]

Originally Posted by shamaho

...

HOWEVER... I also did find (subjectively) that the tension coming out of my string jobs felt way more tight than what I was used from my stringer (also using a drop-weight machine), ...

That's the point here...

Hornet83: give us feedback about it...

[Irvin]

Originally Posted by ART ART

That's the point here...

Hornet83: give us feedback about it...

I knew a guy who strung for six years reading the wrong side of the scale and said he always added weight because they were not tight enough for him. He was reading the wrong side of the weight. I knew another stringer that strung for 15 years and never got the tension he wanted. He started having me string his rackets. I borrowed his drop weight one time and found the weight was way off. He never added the 'other weight' that came with his machine.

Best to do a check to see if the tension you are pulling is what you think it is.

[ART ART]

Agree with you Irvin, the best way here is to use a calibrator or identical device.

[Hornet83]

there was a bit of string that came with the machine (head competition), I didn't tought it would be enough to complete a racquet and was just trying to learn.



There was a few things that I learn about this machine and I would like to share with you:

I found a problem with the clamps, the base was sliping all over the place when pulling tension, I disassemble them and sandpaper the rails and the bases of the clamps and then clean with alcohol, now they grip with minimum effort for tightening.

There was also a bit of looseness on the clamps on the telescopic posts, I found that I can counter that by clamping the string first and move the clamp base in the direction of the tensioner before tightening the clamp base and release the tensioner. (sorry I can't explain better, english is not my first language)

The string was just enough to complete, I tensioned 20kg on the left side of the weight, on the other side the reading was around 26kg. After 2:30h working around the problems and starting all over I'm very happy with my buy, doing everything the same way I will get very consistent stringjobs.

I can definitly conclude that the reading must be done on the left side of the weight, I have an equal racquet that was strung around 3 weeks ago with 25kg and it is much tighter than this one. Hope to get a reel this week and string this racquet again

Thank you all once again
Cheers

[Irvin]

Originally Posted by Hornet83

...There was also a bit of looseness on the clamps on the telescopic posts, I found that I can counter that by clamping the string first and move the clamp base in the direction of the tensioner before tightening the clamp base and release the tensioner. (sorry I can't explain better, english is not my first language)...

I know exactly what you mean. There is one small problem with doing that. If there is too much looseness you could increase tension doing this. Make sure you do not push the base too much toward the tension that when you tighten the base the clamp pulls the string more in the direction away from the tensioner.

[shamaho]

Originally Posted by Irvin

I know exactly what you mean. There is one small problem with doing that. If there is too much looseness you could increase tension doing this. Make sure you do not push the base too much toward the tension that when you tighten the base the clamp pulls the string more in the direction away from the tensioner.

Irvin, could you please ellaborate on this issue? I did not understand the issue but it may be the reason for my higher tension from my stringjobs.

Thanks in advance.

[shamaho]

Originally Posted by Irvin

I know exactly what you mean. There is one small problem with doing that. If there is too much looseness you could increase tension doing this. Make sure you do not push the base too much toward the tension that when you tighten the base the clamp pulls the string more in the direction away from the tensioner.

Telescopic posts? What parts are those?

[Irvin]

Originally Posted by shamaho

Irvin, could you please ellaborate on this issue? I did not understand the issue but it may be the reason for my higher tension from my stringjobs.

Thanks in advance.

Swivel clamps have a post that slides up and down on the clamp (telescopic.)

The clamps have some play in them and when you you tension clamp your string and release tension the tension in the string wants to bend the clamp away from the tensioner. On the next pull that drawback is normally pulled out so it is not a problem but on the clast pull these is no way to get it out except to remove the play before your clamp by pressing the base toward the tensioner.

Because there is ply you have the ability to press the base past the point where all the play is eliminated. Then when you tighten the base it pulls the clamp straight again pulling a higher tension on the string.