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Discussion Starter · #1 · (Edited)
Below is a republished notes in reply to rossing6. It was over at NFAA professional forum, for some reason. It was not posted, so I decided to move it to general archery discussion....

Originally Posted by rossing6
I like the theory of what they do from the aspect of getting the arrow off the string sooner (if that is your problem) but I don't like them unless you have two, one above and one below, as if you bare shaft tune your bow without them through paper and then install one you can see for yourself the affect they have on the arrow, it's quite a change in the way the arrow is being pulled down at the nock during the arrow release from the string. As a new archer (way back when) I used one as the shop set me up with way too long a draw length and I had form issues that resulted in string contact with my forearm. Once I learned about what correct draw length and form should be (a starting place anyway) I took them off. I like the cleanest arrow release from the string that I can get. I also found that all launcher blades seem to kick the back of the arrow upwards, resulting in a tear through paper, so at the time when I was using launcher blades, the string tamer yanked the nock down and then the blade kicked it up, definately not clean. No matter how light you tune the blades, they all do it. I put some on a quick tune 3000 and there is just no way to tune it so this doesn't happen, so I dropped both the launcher and the string tamer. But this is me and how I choose to do it, what is most important is that you get your arrow leaving the bow as cleanly as you can where it shoots straight and put your time into correct practice, shoot only good arrows, not high numbers of so-so shots. Good luck and aim hard...relax.


No a pro, but I am a professional design engineer and consider myself an above average archer and I have been a ballistician and also working archery vibration issues for over 20 years. My interest on STS started when my daughters are doing 580 scores during practice on Vegas Faces until they switch the bows. And the hell broke loose.

So I set up highspeed camera on the range to record the mechanical movements on the new bow, this is the first time I have high speed camera on a bow with STS (mounted on the rear stabilizer 5/16 adopter). What I observed is nothing short of facinating.

If you imagine the bow string acting as a whip, when the part of the whip impacts the STS, the string below the impact area and the string above still kept on moving forward well past the STS shock absorber while the string below STS forming a small sinocoidal wavelet, and the string above the STS forms a larger one. And on my daughter's bow, the larger wave's peak (the furthest point reached) is reaching as far as the rest! In this case a few inches above the rest, so luckily the string did not damage the bow.

For readers don't quite grasp the visual aspect of this. Please remember that if the arrow is launched at 360fps, it is the bowstring that is going 360fps to make the arrow going at that speed. So a bow shooting 360fps arrow without the STS is having a 360fps whip cracking at the archer entire bow arm as well as the bow itself. Without the STS, only the timely retrovertion of the limbs and the cams would stop the whip (the fast moving bowstring) from hitting the riser.

So what does this all mean ?

1. So much for the theory that the low mounted STS's would ensure the timely separation of nock and the bowstring.
Since the 5/16" rear stabilizer adopter have been the most popular location to mount the STS, breaking down the whip at that location does nothing to ensure precise separation of the arrow and the bowstring.

2. the STS does break down a holistic energy (in the form of a fast moving bowstring 'whip') into two segments, in my daughter's case, the low mounted STS creates a major segment (the large whip wavelet above the STS), and a minor segment (the smaller wavelet below the STS). So it does contribute to the 'taming' aspect of absorb the residual energy from the bowstring.

Based on this finding, my wife and I started experimenting with Sounders as well as Darton's string stop, instead of rear stabilizer adopter mounted, both of them are cable rod mounted. In other words, the new STS is much closer to the D-loop/nocking-point, and also much closer to the center of the 'whip'. Using same high speed camera, empirically, we found out that the arrow and the bowstring almost always separates within half an inch of travel from the center-mounted STS, because of the Saunders STS or Darton STS. We even tried to have nocks of different tension, different sizes, different arrow weights as well as velocity. And then we tried on Allegiance as well as Monsters. We have not measure the contribution of such precise separation to the accuracy. But I suspect it could only be beneficial.

With the STS mounted closer towards the center of the riser, the resulting wavelets are also much more balanced between the top 'whip' wavelet and the bottom 'whip' wavelet. With the peaks of both waves advanced no more than 3 inches past the STS, a major improvement.

I think the real incentive to mount an STS on the 5/16 rear stabilizer adopter, is to prevent the high speed whip from hitting the archer's wrist. This says that most STS today are meant to resolve liability issues than to improve accuracy. So in reality, it would be practical for speedbows to have two STS's, one mounted on the rear stabilizer adopter to protect the shooter's forearm and wrist. and the other closer to the nocking point to ensure a precise timing on the separation of arrow and the bowstring during the shot.

So what is the problem with my daughter's bow, well, it was out of tune and the upper limb was moving 1/6 of a phase slower than the lower limb. Once the problem was corrected, their Vegas score went up to 590. Nevertheless, we are getting both of them Saunders as well as Darton cable rod mounted STS.
 

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Discussion Starter · #2 ·
Below is the corrected version of the original. I can no longer edit the message above, so I have add this as a post.

String Tamer and String Stop (STS) Findings
Below is a republished notes in reply to rossing6. It was over at NFAA professional forum, for some reason. It was not posted, so I decided to move it to general archery discussion....

Originally Posted by rossing6
I like the theory of what they do from the aspect of getting the arrow off the string sooner (if that is your problem) but I don't like them unless you have two, one above and one below, as if you bare shaft tune your bow without them through paper and then install one you can see for yourself the affect they have on the arrow, it's quite a change in the way the arrow is being pulled down at the nock during the arrow release from the string. As a new archer (way back when) I used one as the shop set me up with way too long a draw length and I had form issues that resulted in string contact with my forearm. Once I learned about what correct draw length and form should be (a starting place anyway) I took them off. I like the cleanest arrow release from the string that I can get. I also found that all launcher blades seem to kick the back of the arrow upwards, resulting in a tear through paper, so at the time when I was using launcher blades, the string tamer yanked the nock down and then the blade kicked it up, definately not clean. No matter how light you tune the blades, they all do it. I put some on a quick tune 3000 and there is just no way to tune it so this doesn't happen, so I dropped both the launcher and the string tamer. But this is me and how I choose to do it, what is most important is that you get your arrow leaving the bow as cleanly as you can where it shoots straight and put your time into correct practice, shoot only good arrows, not high numbers of so-so shots. Good luck and aim hard...relax.


No a pro, but I am a professional design engineer and consider myself more than an above average archer and I have been a ballistician and also working archery vibration issues for over 20 years. My interest on STS started when my daughters are doing 580 scores during practice on Vegas Faces until they switch the bows. And the hell broke loose.

So I set up highspeed camera on the range to record the mechanical movements on the new bow, this is the first time I have high speed camera on a bow with STS (mounted on the rear stabilizer 5/16 adopter). What I observed is nothing short of facinating.

If you imagine the bow string acting as a whip, when the part of the whip impacts the STS, the string below the impact area and the string above still kept on moving forward well past the STS shock absorber while the string below STS forming a small sinocoidal wavelet, and the string above the STS forms a larger one. And on my daughter's bow, the larger wave's peak (the furthest point reached) is reaching as far as the rest! In this case a few inches above the rest, so luckily the string did not damage the bow.

For readers don't quite grasp the visual aspect of this. Please remember that if the arrow is launched at 360fps, it is the bowstring that is going 360fps to make the arrow going at that speed. So a bow shooting 360fps arrow without the STS is having a 360fps whip cracking at the archer entire bow arm as well as the bow itself. Without the STS, only the timely retrovertion of the limbs and the cams would stop the whip (the fast moving bowstring) from hitting the riser.

So what does this all mean ?

1. So much for the theory that the low mounted STS's would ensure the timely separation of nock and the bowstring.
Since the 5/16" rear stabilizer adopter have been the most popular location to mount the STS, breaking down the whip at that location does nothing to ensure precise separation of the arrow and the bowstring.

2. the low-mounted STS does break down a holistic energy (in the form of a fast moving bowstring 'whip') into two segments, in my daughter's case, the low mounted STS creates a major segment (the large whip wavelet above the STS), and a minor segment (the smaller wavelet below the STS). So it does contribute to the 'taming' aspect of absorb the residual energy from the bowstring.

Based on this finding, my wife and I started experimenting with Sounders as well as Darton's string stop, instead of rear stabilizer adopter mounted, both of them are cable rod mounted. In other words, the new STS is much closer to the D-loop/nocking-point, and also much closer to the center of the 'whip'. Using same high speed camera, empirically, we found out that the arrow and the bowstring almost always separates within half an inch of travel from the center-mounted STS, because of the center location of the Saunders STS or Darton STS. We even tried to have nocks of different tension, different sizes, different arrow weights as well as velocity. And then we tried on Allegiance as well as Monsters. We have not measure the contribution of such precise separation to the accuracy. But I suspect it could only be beneficial.

With the STS mounted closer towards the center of the riser, the resulting wavelets are also much more balanced between the top 'whip' wavelet and the bottom 'whip' wavelet. With the peaks of both waves advanced no more than 3 inches past the STS, a major improvement.

I think the real incentive to mount an STS on the 5/16 rear stabilizer adopter, is to prevent the high speed 'whip' from hitting the archer's wrist. This says that most STS today are meant to resolve liability issues than to improve accuracy. So in reality, it would be practical for speedbows to have two STS's, one mounted on the rear stabilizer adopter to protect the shooter's forearm and wrist. and the other closer to the nocking point to ensure a precise timing on the separation of arrow and the bowstring during the shot.

So what is the problem with my daughter's bow? well, it was out of tune and the upper limb was moving 1/6 of a phase slower than the lower limb. Once the problem was corrected, their Vegas score went up to 590. Nevertheless, we are getting both of them Saunders as well as Darton cable rod mounted STS.
 

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This is very true! and also why I keep mine off the string about 1/8" one more note on the decibel meter they are very close to a little louder with the sts installed, but it sounds quieter because the length of the noise wave is cut down to a 3rd.
Great report poppiewelli!
 

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Discussion Starter · #4 ·
Thanks, Richard,

Honored to have a real archery legend providing such a feedback.
 

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makes sense.... Was there any lateral movement of the loop and nock created by the wave effect. In other words as the lower portion of the string contacted the sts did it pull down on the nock position?
 

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Discussion Starter · #6 ·
makes sense.... Was there any lateral movement of the loop and nock created by the wave effect. In other words as the lower portion of the string contacted the sts did it pull down on the nock position?
The movement of the nock/D-loop (hereafter referred to as the nocking point) is mechanically random, ie it is not totally random but the path can not be easily predicted.

To summarize the test results, if the STS is mounted at the rear stabilizer adopter, ie the low-mount position, the footage suggests that nocking point tends to move higher. I have not collected the data, but the nocking point movement can be easily gathered by going over all the footages of the highspeed videos and a statistics can be tabulated.

One issue we have to consider is that because my wife and I already suspected the timing of the two binary cams was an issue on my daughter's bow, so we can not categorically say that the whipping effect is the cause of the nocking point moving vertically higher. That is why we can only describe the whipping effect with the STS, but unless we can guarantee the timing of the upper and lower energy release to be 100% in synch, it would not be prudent to predict the nocking point movement solely by observing the highspeed videos.

As far as lateral movement is concerned, there is something interesting in the test with a 2007 Allegiance. When we place the Allegiance on its side on an archery shooting bench, which I modified from a bench rest setup for long range rifle ballistic tests, the setup is such that the riser is completely clamped down and will not move during the release and the draw is completely level and aligned with the bow, and the release is completely mechanical done with a lanyard (read no human interaction nor human factor involved whatsoever). During the test, without the STS, the 'shot's with 30" Victory arrows actually caused the bowstring 'whip' to hit the cable guide. Again, it has nothing to do with the bow nor the arrow, and have everything to do with the movement of the whip being mechanically random.
 

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Thanks. Good report. I've never had access to high speed video equipment, but playing it over in my mind I saw just this effect. This just confirms that I'm not a loon. :lol: OK, I guess I could still be a bit loony.
 

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Discussion Starter · #9 ·
Sorry, read my wife's notes wrong. the original message should have said the "...lower limb is 1/6 phase slower...", not the upper limb.
 

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Sorry, read my wife's notes wrong. the original message should have said the "...lower limb is 1/6 phase slower...", not the upper limb.
Are your daughters shooting recurve or compound? Just curious, becaue I think it would make a huge difference. Have you tried the same video on your Bowtech or Matthews? Thanks again for the info!
 

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On a 101st I used to own I found that I got a better tune when using the factory short stop in conjunction with a lower mounted STS. So I agree with what was said about using 2 of them. I know that I also get less vibration with any STS as compared to not using one.
 

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Could you post the High Speed Videos ?? I'd love to see those.
 

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Could you post the High Speed Videos ?? I'd love to see those.
yeap what he said, would like to see videos

maybe i should take the one off my indoor rig
 

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Discussion Starter · #14 ·
Are your daughters shooting recurve or compound? Just curious, becaue I think it would make a huge difference. Have you tried the same video on your Bowtech or Matthews? Thanks again for the info!
My daughters are shooting compound bows, wife and I just don't want to disclose the name of the model and manufacturer because it may come across as product bashing. We did tried on Allegiance and Monster. The result is pretty repeatable.
 

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Discussion Starter · #15 ·
yeap what he said, would like to see videos

maybe i should take the one off my indoor rig
Youtube won't let me upload it. so I am trying to get a proxy version without too much blur. Perhaps I should post some snapshots of the videos first.
 

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While all this may be true.....even if the cycles are different......if they are consistent, it should not affect accuracy......the one thing I noticed with most of the upper mount suppressors, in the footage I have seen, is that the nocking point/loop reaction is far LESS consistent , and the momentum of the loop will usually cause it to "walk" around the string.....it also creates a situation where a long loop, especialy with a tight nock, can and often does create inconsistent "collision" issues.
Traditional D loops and blade type launchers tend not to play really well together.....the loop under will usually have better results, as they are easier to get consistent down pressure for the launcher......but rests like drop aways and containment rets generally work better with a traditional D loop. Only a theory, but those rests tend to give more upward support, with less give (especially containment type rests).
I watched a bunch of of footage trying to determine how much nock movement was due to arrow flex, and how much was string/cam induced or "tune" induced, release types also make a huge difference.
All interesting stuff.........watch the double suppressor systems from the rear.....and pay attention to whether or not you are missing X's up and down, or left and right.
I alwaysl ove hearing other peoples theories , and findings, sometimes they match, and sometimes not.....but different perspectives always are great to help you think differently/learn......thanks for the post.
 

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Discussion Starter · #17 ·
Besides Darton and Saunders, Martin's 2011 bows also have cable guard mounted STS, Martin calls it the SOS. So that makes three reputable companies making these center mounted STS now.
 

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Thanks for the report. Speculating this might be happening I looked into putting a Saunders guard rod mounted STS on my bow. Afterward I decided I would try making one that would somewhat mimic those seen on Bear's upper end bows of late so I designed and built an upper STS for my bow, mounting it so the distance from nock point to each STS contact point was as close to equal as possible. It did reduce shot noise a little (either lower amplitude or shorter duration - I don't know which). About the same timeframe I was experimenting with differences in FOC and overall weight/mass. While it's hard to say how much the upper STS affected nock travel I have observed both of my arrows (460gr and 555gr with FOC 17% and18% respectively) are leaving the bow almost perfectly straight away and grouping quite well - as well or better than before these changes. This all said, I believe the observations from everyone here are valid.
 

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Discussion Starter · #19 ·
Thanks for the report. Speculating this might be happening I looked into putting a Saunders guard rod mounted STS on my bow. Afterward I decided I would try making one that would somewhat mimic those seen on Bear's upper end bows of late so I designed and built an upper STS for my bow, mounting it so the distance from nock point to each STS contact point was as close to equal as possible. It did reduce shot noise a little (either lower amplitude or shorter duration - I don't know which). About the same timeframe I was experimenting with differences in FOC and overall weight/mass. While it's hard to say how much the upper STS affected nock travel I have observed both of my arrows (460gr and 555gr with FOC 17% and18% respectively) are leaving the bow almost perfectly straight away and grouping quite well - as well or better than before these changes. This all said, I believe the observations from everyone here are valid.
Due to the retraction motion of the limbs and the cam's, The compound bowstring at the end of its travel seems not moving at a straight path, like alwayslookin pointed out earlier, which I am not totally in agreement with all he said, but the string does 'walk' left and/or right once it passes the idle point (the point where you start to draw the bow).

I suspect that on the finger shooting bow, the bowstring always wonders in a sinocoidal fashion while moving forward.
 
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