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View Full Version : How hard do you pull on knot?


SpinningForehand
04-20-2008, 08:41 PM
I pull with as much pressure as i can for about 5 seconds usually. Is tihis too much or not enough or okay? Also, how close does the tension bar have to be to being horizontal. Sometimes, it is from 5 to 15 degrees off i think.

YULitle
04-20-2008, 08:51 PM
You pull until all the slack is gone, if you pull right. It isn't about how hard.
http://www.youtube.com/watch?v=IWx3iVPZl_c

Difference of over 5 degrees (depending on the reference tension) are more than a pound. Here's a chart

Based on 60lbs reference tension, these degrees off of paralle (either way) result in these tensions.

5 Deg = ~59.5 lbs.
10 Deg = ~59 lbs.
15 Deg = ~58 lbs.
20 Deg = ~56 lbs.
25 Deg = ~54 lbs.
30 Deg = ~51 lbs.
35 Deg = ~49 lbs.
40 Deg = ~46 lbs.
45 Deg = ~42 lbs.
50 Deg = ~38.5 lbs.
....
90 Deg = ~0.0 lbs.

And a graph. :D
http://farm3.static.flickr.com/2022/2430569738_6b1af6a937.jpg?v=0

vwfye
04-20-2008, 09:33 PM
i tie my cross start knot... pull the first string and recinch the knot. then i repull the 1st string. i'm sure it is overly redundant, but i've been doing it that way so long, i don't even think about it.

ARNICOLINI
04-21-2008, 09:25 AM
I use YULitle's method of cinching up the knots with a starting clamp.

Thanks YULitle!!

As far as the bar being horizontal, here is what I do to help me. I put the stringer on the table that I use as a stand. With the weight very low I position the arm so that when it's horizontal it is about 4 inches away from a wall or desk etc. I then put a torpedo level under the arm and holding it level put a mark on the wall or desk. I have also found that a piece of paper with a fold in the middle (horizontally) will also work. And position that mark or middle of the fold at level. Now when I tension the string I am not guessing at what is horizontal but have a real visual reference to look at. If I am more than a 1/2 inch off I adjust and re drop.

I found myself always wondering where level was and how far off I was when it was a little off. I needed to take the guess work out of it so I could know I have a consistent string job. I was trying out all new strings and I am a relatively new stringer so i wanted to reduce the variables.

Anyway if my description does not make sense let me know and I will take a photo and post.

Mansewerz
04-21-2008, 03:11 PM
I use YULitle's method of cinching up the knots with a starting clamp.

Thanks YULitle!!

As far as the bar being horizontal, here is what I do to help me. I put the stringer on the table that I use as a stand. With the weight very low I position the arm so that when it's horizontal it is about 4 inches away from a wall or desk etc. I then put a torpedo level under the arm and holding it level put a mark on the wall or desk. I have also found that a piece of paper with a fold in the middle (horizontally) will also work. And position that mark or middle of the fold at level. Now when I tension the string I am not guessing at what is horizontal but have a real visual reference to look at. If I am more than a 1/2 inch off I adjust and re drop.

I found myself always wondering where level was and how far off I was when it was a little off. I needed to take the guess work out of it so I could know I have a consistent string job. I was trying out all new strings and I am a relatively new stringer so i wanted to reduce the variables.

Anyway if my description does not make sense let me know and I will take a photo and post.

Photo and post please. I think you could also find a level surface, and then glue a tiny level to the bar/weight mechanism, and presto!

ARNICOLINI
04-22-2008, 08:16 AM
Well I would not want to glue anything to the horizontal bar as that will change the balance. And the balance is what it all work correctly.

I have to string up my racket tonight and I will post some pics tomorrow of what I described above.

ARNICOLINI
04-22-2008, 04:42 PM
Mansewerz,

Here are some photos of what I was describing

http://img212.imageshack.us/img212/7278/1010580ff0.jpg
http://img170.imageshack.us/img170/9080/1010582ek5.jpg
http://img170.imageshack.us/img170/5168/1010584nk6.jpg
http://img409.imageshack.us/img409/4235/1010586ct8.jpg

I just folded the paper in half a couple times to give me some reference lines. I penciled in the middle 3 so you could see it better on camera.

Only takes a minute to level and hang the paper and takes all the guess work out of being level.

stringwalla
04-22-2008, 05:54 PM
Using pliers, I pull upward until the machine comes off the floor (just kidding).

Novice stringers put way too much concern into these details. It really depends on the strings characteristics. Thin guage and or soft multi-filament(Technifibre 17g, Kevlar) strings tend to tighten nicely at low tension. On the other hand, thick and or stiff strings need a little more pull(Hurricane, Prince Nylon)

Just pull until you don't see space in the loop and then pull slightly more to be sure. Be careful with Rip Control and other strings with a fibrous core. They will snap if you go too far-

TenniseaWilliams
04-22-2008, 06:26 PM
...
I just folded the paper in half a couple times to give me some reference lines. I penciled in the middle 3 so you could see it better on camera.

Only takes a minute to level and hang the paper and takes all the guess work out of being level.

Nifty, much more presentable then my top of the Corona label on the shelf trick.


Difference of over 5 degrees (depending on the reference tension) are more than a pound. Here's a chart

Based on 60lbs reference tension, these degrees off of paralle (either way) result in these tensions.

5 Deg = ~59.5 lbs.
10 Deg = ~59 lbs.



YULitle, this is way cool data. Isn't this specific to a certain machine though? Am digging through textbooks trying to figure out why it wouldn't be dependent on the rod length/weight ratio. And does anybody know how the ms200 eco gets away without the bar angle restriction? It does work...

YULitle
04-22-2008, 08:35 PM
Am digging through textbooks trying to figure out why it wouldn't be dependent on the rod length/weight ratio. And does anybody know how the ms200 eco gets away without the bar angle restriction? It does work...

The same amount of bar drops every time and in the same position. The overall weight does not change, but the gravitational force is applied further away from the fulcrum, giving more toque, and thus more tension.

RE: Laserfibre: I, too, would like to know how they get around it.

ARNICOLINI
04-23-2008, 05:03 AM
Nifty, much more presentable then my top of the Corona label on the shelf trick.

See my problem would be I would want to really be neat and constantly relabel the shelf. And I certainly could not take the label off of a full one, then I would never know later what was in the bottle. :)

My only problem with that would be I am already at about an hour to string. I only really string for myself and not often enough to get too much faster. I also am in no hurry, I think my fastest ever was 45 minutes so I am no speed demon. Drinking would only slow me down. :)