# Using a laserpointer to demonstrate what a stabilizer does...



## b0w_bender (Apr 30, 2006)

Hey folks I did a video using my laser pointer to try and show how much of a difference a stabilizer makes. I get a lot of parents asking me if a stabilizer is necessary and I thought it would be nice to be able to pull out my phone and show them what they do and how they work. I know it is real short but people tend not to watch longer videos so I try to keep them as short as possible. I would really appreciate your feedback good bad or indifferent.


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## Warbow (Apr 18, 2006)

What's the YouTube URL? The forum embeds don't work on mobile.


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## b0w_bender (Apr 30, 2006)

Warbow said:


> What's the YouTube URL? The forum embeds don't work on mobile.


here you go
https://www.youtube.com/watch?feature=player_embedded&v=nJHl_DRpg7s


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## Warbow (Apr 18, 2006)

Thanks 

Nice short and sweet demo that effectively shows rather than tells. No need to say high to "YouTube land"* in your intro, though 

I'd be curious to see the laser path during the shot, with and without the stabilizer, preferably with as high a frame rate as you have access to. And, would a higher let off show more torque during the shot, because you can twist more under lighter tension? Also, is this an issue for strong shooters who aren't shaking at anchor?

This brings up the question of what a stabilizer is for. Is it for. Is it for aiming? Or is it for preventing torque during release?


*I think saying hi to "YouTube land" or "Podcastland" and whatnot actually makes video and audio presentations less personal, because it destroys the illusion you are speaking just to the person watching or listening.


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## b0w_bender (Apr 30, 2006)

Warbow said:


> Thanks
> 
> Nice short and sweet demo that effectively shows rather than tells. No need to say high to "YouTube land"* in your intro, though
> 
> ...


Thanks for the feedback, I'll drop the youtube land you make a great point there!

When I did this demo with the kids I had the Laser on a genesis bow it did not matter what the skill level was everyone saw a dramatic increase in their ability to hold spot on. So yes it helps everyone for sure regardless of shooter skill or strength. 

As far as torque during release I'm certain it helps to minimize that too but it is a whole lot harder to demonstrate that. To show torque during the shot may be real problematic. Based on slow motion videos I have watched the string deflecting around the fingers upon release creates some dramatic deflection and I'm thinking it is likely to push the dot a significant distance off the target rather quickly. Like you speculated I think you would really need to have a high speed camera to capture it. Mine is 5 years old before they were able to crank up the frame rates on the retail model cameras so no go for me.


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## UtahIdahoHunter (Mar 27, 2008)

Great video and demonstration. Thanks


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## Mr. Roboto (Jul 13, 2012)

Excellent demonstration.

I have always argued that purpose of the stabilizer is to increase the inertia of the bow where higher the inertia the greater the resistance to change in motion of the bow. The inertia is a function of mass and length squared. This means that the length of the stabilizer has a much greater impact than its weight.

It would be interesting to see the laser test done with a bow without the laser, with a 12" stab, 24" stab, 36" stab, and then go crazy with say a 48 or 60 inch stab that is much greater that what is commercially available. I believe much of today's marketing bling about stabilizers is more about nothing than actually about why the stabilizer does what it does. This video clearly shows its power and purpose.

As for how much does it affect that actual shot? That is a tough one since the arrow is only in contact with the string for about 15ms during the shot. After the 15 ms, the stabilizer does nothing to affect the shot anymore.


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## Last_Bastion (Dec 5, 2013)

Very cool!

Thanks for sharing


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## b0w_bender (Apr 30, 2006)

Mr. Roboto said:


> Excellent demonstration.
> 
> I have always argued that purpose of the stabilizer is to increase the inertia of the bow where higher the inertia the greater the resistance to change in motion of the bow. The inertia is a function of mass and length squared. This means that the length of the stabilizer has a much greater impact than its weight.
> 
> ...


Excellent, response I've had a bunch of people ask about the 12" stabilizer mostly from the hunting crowd so I suppose I should do a video as you described however there is that one variable that is hard to control, the old fart holding the bow. You kind of have to trust that he is doing the same thing on each session.


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## erickatgta (Apr 22, 2013)

real helpful video! thx a lot!


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## R&B (Oct 4, 2006)

NICE!!!

Well Done.

-R&B


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## ButchD (Nov 11, 2006)

I am getting an error message. Tried both links 4 or 5 times. Any suggestions?


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## lksseven (Mar 21, 2010)

Great demo!


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## lksseven (Mar 21, 2010)

Mr. Roboto said:


> Excellent demonstration.
> 
> I have always argued that purpose of the stabilizer is to increase the inertia of the bow where higher the inertia the greater the resistance to change in motion of the bow. The inertia is a function of mass and length squared. This means that the length of the stabilizer has a much greater impact than its weight.
> 
> ...


Hi Pete,
In my experience the stabilizer affects the shot very much, both in terms of aiming stillness (as demonstrated in this video), but also in terms of arrow flight characteristics/impact point at the target, and grouping (if that was your thrust). Most people are amazed when they see the same arrows shot out of the same bow with the only difference being stab/no stab or just changing the weights on the end of the stab.


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## lksseven (Mar 21, 2010)

Could you tell us the laser brand/model?


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## b0w_bender (Apr 30, 2006)

ButchD said:


> I am getting an error message. Tried both links 4 or 5 times. Any suggestions?


Not sure why the link isn't working, try to do a search on Youtube.com for Stabilizer and Laser



lksseven said:


> Could you tell us the laser brand/model?


Honestly I don't know who makes it. There are literally thousands to choose from on ebay I bought is several years ago and I'm pretty sure any of them would work.


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## lksseven (Mar 21, 2010)

b0w_bender said:


> Not sure why the link isn't working, try to do a search on Youtube.com for Stabilizer and Laser
> 
> 
> Honestly I don't know who makes it. There are literally thousands to choose from on ebay I bought is several years ago and I'm pretty sure any of them would work.


Sure. I ask because I tried to find a laser pointer I could use to strap to my string hand to demonstrate how much more stable the aiming picture because with a proper anchor married up to the jaw versus a tentative 'touch' or even hand float anchor. But the only one's I could find required the on button be continually pressed with one's finger or thumb, and I couldn't hold the string and the laser at the same time! Then I just forgot about that notion. I'll cast around for one with a toggle switch, not just a pressure button.


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## Malak77 (Feb 10, 2016)

lksseven said:


> Sure. I ask because I tried to find a laser pointer I could use to strap to my string hand to demonstrate how much more stable the aiming picture because with a proper anchor married up to the jaw versus a tentative 'touch' or even hand float anchor. But the only one's I could find required the on button be continually pressed with one's finger or thumb, and I couldn't hold the string and the laser at the same time! Then I just forgot about that notion. I'll cast around for one with a toggle switch, not just a pressure button.


Just wrap electrical tape around the pointer where the switch is and leave a folded-over flap at the end for easy removal.


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## b0w_bender (Apr 30, 2006)

lksseven said:


> Sure. I ask because I tried to find a laser pointer I could use to strap to my string hand to demonstrate how much more stable the aiming picture because with a proper anchor married up to the jaw versus a tentative 'touch' or even hand float anchor. But the only one's I could find required the on button be continually pressed with one's finger or thumb, and I couldn't hold the string and the laser at the same time! Then I just forgot about that notion. I'll cast around for one with a toggle switch, not just a pressure button.


Ah good point yes mine does have a toggle switch. hmmm, I'll look a little harder.


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## Warbow (Apr 18, 2006)

lksseven said:


> Sure. I ask because I tried to find a laser pointer I could use to strap to my string hand to demonstrate how much more stable the aiming picture because with a proper anchor married up to the jaw versus a tentative 'touch' or even hand float anchor. But the only one's I could find required the on button be continually pressed with one's finger or thumb, and I couldn't hold the string and the laser at the same time! Then I just forgot about that notion. I'll cast around for one with a toggle switch, not just a pressure button.


Does yours have an external membrane switch on a cable? If so it would be pretty easy to swap out the momentary swtich with a latching one.


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## b0w_bender (Apr 30, 2006)

I'm pretty sure this is the one I bought
http://www.ebay.com/itm/Astronomy-5...387125?hash=item2a4a5f5135:g:Uj4AAOxyB9RS1ZHJ

Astronomy 5mW Green Laser Pointer II w/ On & Off Switch Up to 7500 Feet!

It has a clicky toggle switch on the back


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## lksseven (Mar 21, 2010)

b0w_bender said:


> I'm pretty sure this is the one I bought
> http://www.ebay.com/itm/Astronomy-5...387125?hash=item2a4a5f5135:g:Uj4AAOxyB9RS1ZHJ
> 
> Astronomy 5mW Green Laser Pointer II w/ On & Off Switch Up to 7500 Feet!
> ...


Awesome! Thank you!


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## grantmac (May 31, 2007)

Typical archers, 75% of the posts are about the equipment and only 25% about the data 

Grant


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## Arcus (Jul 7, 2005)

Thanks for posting. I'm curious about how much of the effect is due to the extra weight, i.e., would you see a similar effect by adding weight to the riser instead of adding a stabilizer.


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## Mr. Roboto (Jul 13, 2012)

lksseven said:


> Hi Pete,
> In my experience the stabilizer affects the shot very much, both in terms of aiming stillness (as demonstrated in this video), but also in terms of arrow flight characteristics/impact point at the target, and grouping (if that was your thrust). Most people are amazed when they see the same arrows shot out of the same bow with the only difference being stab/no stab or just changing the weights on the end of the stab.


This is one of the puzzles that I am trying to get an answer to. I won't question a person that tells me that they are getting better groups with a stabilizer vs without a stabilizer. People tell me that a small 12" stab on a Trad bow will get them 10 more points for indoors. I am not questioning that either.

The excellent video clearly shows that two things are happening. Jitter is significantly improved, and the floating is improved greatly. Both of those in them selves will help improve shooting performance. That is one aspect, and probably the most important aspect.

I have been puzzling at how much that stabilizer has an impact on the actual shot during the 15ms power stroke. I have been watching a lot of high speed video specifically studying the riser's response during the power stroke. There is hardly any movement during those few milli-seconds. The bulk of the movement begins after the arrow is off the string. We know that as the string comes off the fingers there is a lateral force on both the arrow and the limbs. The creates torque. The bow's inertia resists change in motion from the applied torque. So one would think that more inertial from a stab will reduce the torque in the bow. I can understand that. But it gets really complicated in that the plunger is also doing a lot of work to respond to the bending of the arrow and the movement of the bow, so the plunger is doing a lot of work to correct for the torque from the fingers loosing the arrow. There is a lot going on during this time frame. And I am pretty sure that it does have a contribution to the ballistic path of the arrow. But exactly how much? I am thinking its small when compared to the global improvement of bow stability in the holding. 

It would be great if we could see some tests done from shooting machines that can remove the archer out of the equation, and see how different stabilizers and weights affect the shot to shot consistency.

Videos like this really get the thought juices flowing.


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## Vittorio (Jul 17, 2003)

Mr. Roboto said:


> ........
> 
> I have been puzzling at how much that stabilizer has an impact on the actual shot during the 15ms power stroke. I have been watching a lot of high speed video specifically studying the riser's response during the power stroke. There is hardly any movement during those few milli-seconds. The bulk of the movement begins after the arrow is off the string. We know that as the string comes off the fingers there is a lateral force on both the arrow and the limbs. The creates torque. The bow's inertia resists change in motion from the applied torque. So one would think that more inertial from a stab will reduce the torque in the bow. I can understand that. But it gets really complicated in that the plunger is also doing a lot of work to respond to the bending of the arrow and the movement of the bow, so the plunger is doing a lot of work to correct for the torque from the fingers loosing the arrow. There is a lot going on during this time frame. And I am pretty sure that it does have a contribution to the ballistic path of the arrow. But exactly how much? I am thinking its small when compared to the global improvement of bow stability in the holding.
> 
> ...


All things attached to the riser during those few milliseconds were the arrows travels with nock still on the string but with no other contact with any other part may give variation to the path of travel. 

Limbs ability to recover fast to the correct line are usully those more considered by archers (torsional and vertical stability of limbs) but all other parts may influence the result. A stabilizer (or its terminal part=damper) that bends too quickly may influence the path of the nock before it leaves the bow. This is the reason why longer stabilizers have to be stiffer than short stabilizers, and that high weights on their tips need stiffer rods, and that high weights on dampers need stiffer dampers, and that long rods angled down need to be much stiffer than those perpendicular to the riser. But also that heavy sights need stiffer extensions or shorter extensions (sight is also a stabilizer).

High speed video are widely available nowdays , but often people don't know what to really search on them. Moving parts before nock leaves the string are those to be checked in those videos. 

Yes, weight distribution of stabilizers(or weights for BB) and related full bow reaction in relationship to the variations of the pressure point at the release are the most important factor to the stability of the nock path. Button is not, apart from the fact that a stiff button (week arrow) makes the arrow abandoning the contact to the riser faster.

Shooting machines have no practical use in checking anything on a recurve bow if they do not simulate a release by fingers. 

OK, matter should need a couple of books to be analized in full, but as far as inertia is concerned, pls consider a riser with infinite mass. It will not move at release, so will not need stabailizers of any kind. But, in the real world, no one can handle such a mass. So 
you wil need a compromise made by rods and weights here and there to get a similar but not same result. 

P.S.
Today tendency to go to extreme weights, 4 to 5 kg total weigth for BB or close 1Kg on top of long and back rod for compounds is the simplest solution to try to control bad releases or bad designed bows by increase of the total mass, usually forgetting that a good shooting form is the key to the success, in first place. 
Then Sergio Pagni comes, with his old Beiter long rod with limited weigth on tip , almost no back weight, his very old Cascade release, and gets Vegas 2016 Crown ...


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## Mr. Roboto (Jul 13, 2012)

A lot of good points here, thanks.

I have been studying the mathematics of archery for a while here from various published papers, and inertia is largely ignored in the models. They mainly focus on velocity and not trajectory. So now I am working on modeling the archers paradox in the whole bending and vibration of the arrows. The bow's inertia comes into play at that point, along with how the string comes off the fingers, and the plunger and arrow rest. Its very complicated. Its all math, and the reality of the human element is the most difficult thing to model. But good math models can point one in the direction of studying the relative magnitudes of the various components on the bow.

Careful experiments can also show the same things. I have already begun gathering multiple simultaneous accelerometer data on the riser during the shot sequence and measuring the x axis (arrow direction) and y-axis (plunger direction) the torque about the vertical (z) axis of the bow (obtained from multiple y-axis accelerometers). I can see what the bow is doing during the entire time the arrow is attached to the string. I have been doing this while shooting the barbow in my hand. What I find most amazing is how uniform from shot to shot the accelerometer data. Compared to a lot of the people who post here, I am not a good archer. Because I am not a good archer, but the data is very consistent, it gives an indicator that the dynamics of the power shot sequence may be useful without the use of a shooting machine. I also find that shooting a barebow with and with out a 30 inch stab is almost identical. There is a little difference in that there is a slight shift in the frequency and amplitude. But it is small enough that it could also be interpreted as variation with the archer's ability to shoot. Now this is measuring the riser, and not the arrow. One thing for sure is that from the accelerometer data that I have measured so far, with and without a stabilizer didn't show any large change. This gives an indicator that the stabilizer has more of an impact on the holding stability of the bow than in the actual power stroke. Which the laser video clearly shows.

I am not saying that the stab or weights, or dampeners don't have an effect on the dynamics of the arrow flight. Especially since small changes at the riser have large multiplying affects at the arrow nock since it is further away for the bow's CG when attached to the string. But it would be nice to be able to start to quantify the impact of these influences.

This is some really exciting stuff.


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## b0w_bender (Apr 30, 2006)

Mr. Roboto said:


> A lot of good points here, thanks.
> 
> I have been studying the mathematics of archery for a while here from various published papers, and inertia is largely ignored in the models. They mainly focus on velocity and not trajectory. So now I am working on modeling the archers paradox in the whole bending and vibration of the arrows. The bow's inertia comes into play at that point, along with how the string comes off the fingers, and the plunger and arrow rest. Its very complicated. Its all math, and the reality of the human element is the most difficult thing to model. But good math models can point one in the direction of studying the relative magnitudes of the various components on the bow.
> 
> ...


I"m thinking you and JoeT will get along like gangbusters 
I would tend to doubt that a stabilizer would have any affect on the arrow directly, which appears to be what your data is saying. I think what people are curious about is if the stabilizer is helping to hold the riser more stable for those few milliseconds that the arrow is in contact with it during the power stroke. Now although I don't have the slow mo camera to prove I strongly suspect it does and Vitero seems to be on board with that too. At the very least I'm 100% certain it doesn't hurt the arrow flight. It clearly helps with the aiming process particularly if your sight is on a longer extension bar.


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## Warbow (Apr 18, 2006)

@MrRoboto

What is the sampling rate of the accelerometers? Is there any chance that their resolution is too low for the frequencies involved?


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## Mr. Roboto (Jul 13, 2012)

I borrowed a 600 fps camera from work to do some high speed video to see if it can catch anything interesting between a bow with and without a stab. Bottom line, 600 fps is not fast enough to catch tiny movements. But it does show a lot of movement in the riser that begins immediately after the arrow leaves the string. I have been looking for a camera (that I can afford) that is much much faster than that for while now. I was hoping that 600 fps along with the accelerometer data would show some clear changes. So I am back to the drawing board on that one.

Yeah, Joel was a lot of fun to shoot with when he used to do field shoots up here. I am hoping he will do Darrington again this year.


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## Mr. Roboto (Jul 13, 2012)

Warbow said:


> @MrRoboto
> 
> What is the sampling rate of the accelerometers? Is there any chance that their resolution is too low for the frequencies involved?


I was sampling at 10,000 Hz


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## Warbow (Apr 18, 2006)

Mr. Roboto said:


> I was sampling at 10,000 Hz


Well that is definitely higher resolution than a 30 fps video of laser deflection :-D How accurately can you predict grouping by the accelerometer data? I'm really curious about the bow deflection during shoot, but I lack the equipment and expertise to run these kind of tests myself.


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## Bergloch (Dec 19, 2014)

Excellent, clever video, Bowbender. You've proved once again that a picture is indeed worth a thousand words. Nice work!


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## batsonbe (Nov 29, 2012)

awesome video and concise, I like it!


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## lksseven (Mar 21, 2010)

Not sure whether or not this falls under the category of "who you gonna believe, my math or your lyin' eyes" ... but my anecdotal observation is that if you shoot bareshafts out of a bow set up barebow (sans stabilizer), and then shoot bareshafts out of that bow with a stabilizer and 15oz of weight on the front, the effect on arrow flight and impact point in the target is dramatic, and cannot be more than minutely accounted for from an explanation that the aiming is better. I would suggest, too, that a BIG variable is the tension of 'hold' that is being applied to the bowgrip by the bowhand of the archer. A neutral inert hold makes the stabilizer much more impactful than will a hamfisted Schwarzenegger-esque squeeze.


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## b0w_bender (Apr 30, 2006)

lksseven said:


> Not sure whether or not this falls under the category of "who you gonna believe, my math or your lyin' eyes" ... but my anecdotal observation is that if you shoot bareshafts out of a bow set up barebow (sans stabilizer), and then shoot bareshafts out of that bow with a stabilizer and 15oz of weight on the front, the effect on arrow flight and impact point in the target is dramatic, and cannot be more than minutely accounted for from an explanation that the aiming is better. I would suggest, too, that a BIG variable is the tension of 'hold' that is being applied to the bowgrip by the bowhand of the archer. A neutral inert hold makes the stabilizer much more impactful than will a hamfisted Schwarzenegger-esque squeeze.


Good post, I doubt anyone would be surprised that a stabilizer has an affect on the point of impact of an arrow. Not only would I expect the stabilizer to delay or slow the motion of the riser at the point of release I would also expect it to make that motion marginally more consistent and lower in amplitude. The issue is trying to visually demonstrate it. Mr Robato is throwing math and equations at it you mentioned anecdotal evidence and most folks including me are talking intuitively but setting up a decent slow mo camera is what I think most archers would love to have. 

By the way aside from the human element I think your bare shaft experiment is a reasonably sound test. Of course you knowing the bow does or doesn't have a stabilizer may affect the results but given enough people shooting a decent number of shots you could show some continuity of results and that would be significant. Especially if each participant was not aware of the others results. I think using a sight in that experiment and require grouping would help isolate the human element too. Now translate the offset arrow impact in to good or bad becomes another issue. So you can demonstrate that the impacts are different. So what, why is that an issue? Assuming the groups that were shot without the stabilizer were always larger one might be tempted to conclude that the stabilizer makes the bow more accurate. However given the fact that the shooter knows there is no stabilizer would of course skew the results. Humans cannot be depended upon to be non-biased. So you would need to have a shooting machine that accurately represented an average grip pressure and accurately simulate a finger release. If you made the finger release variable then you could setup an experiment that demonstrated the difference in point of impact from a variance in finger release would be measurably smaller using a stabilizer than that from a bow without a stabilizer. Well that is my hypothesis anyway. Now if you could conclusively prove that then I think most of us would be less than surprised. So personally I think it is more than enough for me to advocate using a stabilizer because the ten second video is pretty obvious there is a huge benefit in the aiming alone. In other words ya sure we believe there is a benefit in the stability of the bow during the power stroke but the aiming benefit alone is overwhelming enough that you should use a stabilizer.


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## kshet26 (Dec 20, 2010)

If you're looking for high frame rate cameras and arent afraid of technical camera gear, you can always rent a Phantom for a couple of grand. The one I've used can do 10k fps.


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## b0w_bender (Apr 30, 2006)

kshet26 said:


> rent a Phantom for a couple of grand.


That right there is funny I don't care who you are!


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## Warbow (Apr 18, 2006)

kshet26 said:


> If you're looking for high frame rate cameras and arent afraid of technical camera gear, you can always rent a Phantom for a couple of grand. The one I've used can do 10k fps.


_10,000_ fps? Finally, a way to make my firm seen rock solid. 

I wonder how the Slow Mo Guys afford their cameras? Do YouTube bidders really pay that much?


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## Mr. Roboto (Jul 13, 2012)

I am not saying anyone is a liar. The video clearly shows the laser dot is more stable with the stab and without the stab. Countless archers shoot with stabs for both recurve and compound. Even barebow people put on stabs and swear they get 10 points when doing so. Empirical results have shown that. I am not contesting that, nor will I even try to contest it.

My point is trying to clearly understand exactly why it does what it does. I am not trying to say it doesn't do anything.

As for my accelerometer data. It was taken at the riser. So far, my tests have shown that there is very little difference in the measurements from shooting with or without the stab. This is acceleration at the riser. It was not measuring the affect of the arrow flight. Lets just say that I was very surprised to get the results that I did. I was expecting to see a significant obvious difference in the tests where it would be easier to model the influence of the stabilizer. When people see big changes in shooting results when using or not using a stabilizer, one would naturally think that one can quantify and measure the differences in the bow.

I just hope no one is thinking that I am calling them a liar just because I am trying to understand the precise physics as to why the stabilizer does what it does.


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## skycolt (Jan 17, 2016)

That's nice.


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## b0w_bender (Apr 30, 2006)

Mr. Roboto said:


> I just hope no one is thinking that I am calling them a liar just because I am trying to understand the precise physics as to why the stabilizer does what it does.


Data doesn't lie. 
that is the cool thing about science right, you design your testing and experimentation to either prove or disprove a hypothesis. It may be that you aren't measuring the right thing or that your equipment isn't measuring as accurately as you need. We both know that you can use mathematical formulas to describe the amount of stabilization you get based on weight and length. We know it does something. Reporting what you measure isn't calling anyone out it is simply what you found. I think it is great that you are noodling it in such detail. 

I know when I mentioned that you "can't trust a human to be non-biased", I'm fully aware of the irony of me showing a laser beam held by a human. OK so there is a slight bit of hypocrisy there but at least its an easy experiment that anyone can duplicate. I'm kind of surprised I didn't get at least a couple of good natured pokes over that one.


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## Ms.Speedmaster (Dec 10, 2010)

Arcus said:


> Thanks for posting. I'm curious about how much of the effect is due to the extra weight, i.e., would you see a similar effect by adding weight to the riser instead of adding a stabilizer.


I would imagine it would be a different effect, due to the stability that the rod is giving in the same way that a high wire tight rope walker uses a long stabilizing rod on the horizontal. If that tight rope walker just put sand bags around his ankles, it would provide a different response. Probably more grounded than without, but nothing to offer balance?

It's like there's two different factors. Weight, as we weight our BB risers, provides less bounce. Whereas the rod provides more balance. 

Idk, I'm just thinking out loud.

I'm following the thread with interest and plan on experimenting with my barebow.


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## Ms.Speedmaster (Dec 10, 2010)

One more thing I will say, nothing has improved my score more than just letting go of the bow. And I believe that the rod makes it more forgiving for those who haven't completely let go. The rod obviously reduces torque, as seen in the video. 

Today, watching BB compound guys with rods, in the same category as me with my weighted recurve, it made me more determined to do better with my rig. Yesterday, I shot an NFAA 254. Today a 271. The only difference was... I was more intentional in not manipulating the bow. My bow hand thumb was almost hitch hiking. 

Gonna order me a laser to play. 

Good stuff.


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## lksseven (Mar 21, 2010)

Ms.Speedmaster said:


> One more thing I will say, nothing has improved my score more than just letting go of the bow. And I believe that the rod makes it more forgiving for those who haven't completely let go. The rod obviously reduces torque, as seen in the video.
> 
> Today, watching BB compound guys with rods, in the same category as me with my weighted recurve, it made me more determined to do better with my rig. Yesterday, I shot an NFAA 254. Today a 271. The only difference was... I was more intentional in not manipulating the bow. My bow hand thumb was almost hitch hiking.
> 
> ...


Lynda,

Like a good waiter, you want that thumb to be close by, but not intruding ...

So, here's two pics, one with stab (30", 15oz on front, 20yd) and the next pic without the stab on the bow. It didn't surprise me that the 'no stab' group was higher, but it did surprise me that the group wasn't removed sideways as well (I guess you'll have to take my word for it that my bowhand was letting the bow do what it wanted to do). I've have other bow setups that would have shown a marked difference horizontally as well as vertically. So now I don't know what I know or don't know! Except I do know that the sight is mucho easier to hold on the spot with the stabilizer.

With Stab ..








without Stab ..


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## grantmac (May 31, 2007)

Except I do know that the sight is mucho easier to hold on the spot with the stabilizer][/QUOTE]


This is the reason I advocate so strongly for adding a stab before sight with new archers. A sight without one is very unsteady.

Grant


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## Ms.Speedmaster (Dec 10, 2010)

lksseven said:


> Lynda,
> 
> Like a good waiter, you want that thumb to be close by, but not intruding ...


Oh, believe me I know. Coach Lee was very specific about this in December. In fact, it was explained that there should be a little pinch at the base of the thumb, which surprised me, but an OR archer can get away with that. Not wanting to derail, but that ain't gonna work for this BB archer.

My laser should be here by the end of the week. Looking forward to experimenting. 

We will tinker with OR, BB and compound... because, we are finding some interesting results with weight adjustments. Just a couple of days ago, one of my staff was given a bow by Moxie, and he just threw a sight and rod on it to shoot. He was nailing X's right out of the gate. Whereas he had not been as successful with his Hoyt, which had about 3 tons of weight on it. Slight exaggeration, but you get the picture.

b0w_bender - thank you for posting this. This will keep the science side of X10 Archery busy for a while.


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## b-a-maniak (Apr 19, 2014)

Nicely done! Excellent contribution.


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## Mr. Roboto (Jul 13, 2012)

Okay, for you data junkies.

The image below shows the acceleration of the riser in he direction of the arrow. The accelerometer was bolted parallel to the arrow at the same elevation as he plunger. There are three shots shown here. The data acquisition was 10,000 samples per second, and the trigger was set to 2g's with a 10% pre-trigger (this lets you see the vibration before the rigger). The shots were about #45 OTF. There was NO Stabilizer on this bow for these shots. The initiation of the shot started at 0.040 seconds. A about 0.057 seconds, the string was at the brace height position, and this is the beginning of the shock we feel and see in the bow. The arrow is already off the sting at this point in time.








The next image shows three shots with a 30 inch stabilizer attached to the bow. Not a lot of earth shattering differences.








Nice to see from an accelerometer point of view my releases appear to be consistent.


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## Warbow (Apr 18, 2006)

Mr. Roboto said:


> Okay, for you data junkies.
> 
> The image below shows the acceleration of the riser in he direction of the arrow. The accelerometer was bolted parallel to the arrow at the same elevation as he plunger. There are three shots shown here. The data acquisition was 10,000 samples per second, and the trigger was set to 2g's with a 10% pre-trigger (this lets you see the vibration before the rigger). The shots were about #45 OTF. There was NO Stabilizer on this bow for these shots. The initiation of the shot started at 0.040 seconds. A about 0.057 seconds, the string was at the brace height position, and this is the beginning of the shock we feel and see in the bow. The arrow is already off the sting at this point in time.
> View attachment 3809410
> ...


Wow, that is surprisingly consistent shot to shot...


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## Mr. Roboto (Jul 13, 2012)

Now this is where one starts to notice differences.

Here is the data for one of the y-axis accelerometers. This one was placed parallel to the plunger - perpendicular to the arrow. Z-axis points up. This was bolted to the riser in the same plane as the arrow and the x-axis accelerometer. Again, three different shots are shows here, with the same 2g trigger. Again at about 0.057 seconds (approximately 0.017 seconds after the initiation of the launch) the string is at the original brace height position, and the arrow is already gone (i.e. no longer attached to the string).

These shots were done with no stabilizer








The next image shows three consecutive shots done with a 30 inch stabilizer. Here we can start to see lateral differences in the acceleration amplitudes (the dreaded torque)








The primary frequencies hasn't change, so the stabilizer doesn't appear to affect the vibration frequency of the bow during the power stroke. But when we look at the amplitude of the vibration, there is an obvious change between 0.050 an 0.055 seconds. This is about 10 to 15 ms after this initiation of the launch. Or about the last third of the time the arrow is connected to the string.

When looking at the previous post's x-axis data, the stab does not appear to have any influence on the riser in the direction of the arrow during he power stroke. Which is what would be expected if the bow was balanced so that it wasn't going through that hyper spin that seems to be popular these days. But there is some measureable differences in the lateral direction during the last 1/3 of the power stroke, where it appears that the stabilizer contributed to reducing the amplitude of lateral vibration at the riser. Though the arrow isn't in contact with the riser/plunger at this point, it is still connected to the string. Thus lateral motion in the riser does have a corresponding lateral motion through the limbs and to the string.

Fun stuff, right?


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## theminoritydude (Feb 11, 2013)

I'm not as interested in the length of the stabilizer, as I am in the position of the center of mass of the bow. I think that will give you some pretty interesting numbers.


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## theminoritydude (Feb 11, 2013)

Having said that, do note that chances for the high frequencies demonstrated to have any non-negligible effects on the score, is very remote.


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## Vittorio (Jul 17, 2003)

Mr. Roboto said:


> ..........
> When looking at the previous post's x-axis data, the stab does not appear to have any influence on the riser in the direction of the arrow during he power stroke. Which is what would be expected if the bow was balanced so that it wasn't going through that hyper spin that seems to be popular these days. But there is some measureable differences in the lateral direction during the last 1/3 of the power stroke, where it appears that the stabilizer contributed to reducing the amplitude of lateral vibration at the riser. Though the arrow isn't in contact with the riser/plunger at this point, it is still connected to the string. Thus lateral motion in the riser does have a corresponding lateral motion through the limbs and to the string.
> 
> Fun stuff, right?


Yes,fun, but exactly what had to be expected, and thanks for the detailed measure of it. 

The stabilizing system should also contribute to the stability of the riser during the travel of the nock attached to the string , and of course here we go to the distribution of the weight in the stab system and the mass (lateral inertia) of the stabilized riser at the release. Adding just a long rod to the riser makes thing better for aiming and longitudinal stability, but not so much in lateral /torsional stability. There the short side rods and their balnce come into effect. Or, in BB how you adjust the weights (not on front, only)


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## kshet26 (Dec 20, 2010)

This seems to support the observed behavior of barebow archers needing stiffer arrows than Oly. It looks like this is due to nock offset/shaft rotation.

Curious as to why the g's increase in the x-axis long after the arrow is gone. Could this be due to string oscillation resolving from side-to-side to front-to-back?


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## theminoritydude (Feb 11, 2013)

kshet26 said:


> This seems to support the observed behavior of barebow archers needing stiffer arrows than Oly. It looks like this is due to nock offset/shaft rotation.
> 
> Curious as to why the g's increase in the x-axis long after the arrow is gone. Could this be due to string oscillation resolving from side-to-side to front-to-back?


The readings are a result of acceleration/deceleration, not the force experienced by the accelerometer, which is now part of the riser. There are two main energy sinks in the system, 1) The arrow and 2) The bow's collective dampening system.

With the larger of the two sinks having done its job and left the system, at around the same time, the limbs abruptly coming to a stop, all residual energy not used will be bounced around the bow, causing the spike you see.

If the data was obtained with a heavier arrow, the magnitude of the spike will be correspondingly smaller.


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## b0w_bender (Apr 30, 2006)

Mr. Roboto said:


> Now this is where one starts to notice differences.
> 
> Here is the data for one of the y-axis accelerometers. This one was placed parallel to the plunger - perpendicular to the arrow. Z-axis points up. This was bolted to the riser in the same plane as the arrow and the x-axis accelerometer. Again, three different shots are shows here, with the same 2g trigger. Again at about 0.057 seconds (approximately 0.017 seconds after the initiation of the launch) the string is at the original brace height position, and the arrow is already gone (i.e. no longer attached to the string).
> 
> ...


Mr. Roboto Dude, I could kiss you! OK perhaps that is a bit strong, I suppose a hug would be more appropriate. :hug: Your results are intuitively what I would have expected so that gives me a bit of a warm and fuzzy. The motion of the limbs would generate a force inline with the stabilizer so my thought was that a stabilizer wouldn't be doing much along that vector. Anyone who has watched a slow motion finger release can see the significant amount of horizontal (torque) motion and because of the finger release, it is most likely to be the motion that is most inconsistent. This is where I too would have expected to see a stabilizer having the greatest affect and you have shown it does. You have demonstrated that rather well. Now there are a ton of additional experiments that I would love to do if I had your equipment but you have just completed the primary one. I'm going to be making another video with 3 or 4 different stabilizers including a stand-in for a broomstick. I would love to be able to explain this lateral motion affect, can I use the perpendicular graph in my next video? Lastly with a compound having parallel limbs and a mechanical release I'm thinking there is also a shorter time interval for the power stroke would you think a stabilizer is doing even less? I'm guessing that your equipment would have a real hard time seeing a significant difference with a modern compound during the power stroke, what do you think?


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## Ms.Speedmaster (Dec 10, 2010)

Mr. Roboto said:


> Fun stuff, right?


YES!! Geek overload. 

Would it be possible for you to do the same experiment with and without compact weight added, no rod, to see change in motion in both directions? Say around 20oz added to the lower part of the riser? I guess technically, to get the data I'm looking for, there shouldn't be a sight on there either. 

Also, may I share/use your data charts to show others? With full credit, of course.


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## grantmac (May 31, 2007)

I'd like to see highs peed motion capture during a shot with various stabilization. Of particular interest would be during the aiming phase since in my mind that is where the main benefit of stabilization occurs.

Grant


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## Warbow (Apr 18, 2006)

So, the accelerometer data is very cool and the resemblance between shots is amazing. But it occurs to me that the difference in angle at the bow between an x and a miss is so slight that it not only can't be seen at this level of zoom on the graphs, but that it might well be below the resolution of the accelerometers. :dontknow:


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## kshet26 (Dec 20, 2010)

Warbow said:


> So, the accelerometer data is very cool and the resemblance between shots is amazing. But it occurs to me that the difference in angle at the bow between an x and a miss is so slight that it not only can't be seen at this level of zoom on the graphs, but that it might well be below the resolution of the accelerometers. :dontknow:


Correct. It's also below what will be discernible in high-speed film. Fraction of a fraction of a degree.

Edit: I'd also add that accelerometers, as their name suggests, can only report on acceleration, not speed. You'd need a way to measure absolute positioning.


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## Mr. Roboto (Jul 13, 2012)

The accelerometers that I am using are piezoelectric. They are analog so resolution comes down to the accuracy of the data acquisition board. The one that I am using is a 24 bit DAQ. With these accelerometers I should be able to resolve down to 5.9e-6 g's or or about 57 micrometers/s/s or about 0.002 inch/s/s. Sampling rate was 10,000 hz. I can sample up to about 57 kHz, but chose 10kHz since other papers have reported that the dominant energy frequencies are less than 200 Hz.

It is true that acceleration and displacement are not the same, and double integrating acceleration in the time domain is essentially useless. Needs to be done in the frequency domain if that is even doable for this data. That is a bit of work to do and it is on my list of things to do.

So how small of a change in acceleration relates to a change in the arrow position? Well that is still to be determined. But this data does show where some changes are occurring, and where changes are not occurring.

I am not good enough of an archer to be able to hold a bow steady enough to correlate accelerometer data with how the arrow hits the target down range. But I can establish trends.

As for video to measure displacement. That depends on the camera. There are cameras that can do over a million frames per second. But the frame rate doesn't need to be that high. The real issue is the video resolution. If the camera can do 1080 dpi at 10,000 fps, and the camera was focused down to the entire field of view was just 1 inch, then the camera can resolve 0.001 inch displacements at 10,000 frames per second. At that point one can get direct correlation between acceleromter data and displacement data. If you have 2 accelerometers placed 1 inch part then within that zone one can then get an angular resolution of 0.057 degrees. If the archer has a 28 inch draw and a 9 inch brace height, then the projected angular uncertainty at the string due to rotation of the riser will be in the range of 0.028 inch to 0.009 inch. So using video can be either really good or still not good enough depending on accuracy needed.

But is precise data really needed? If one can quantify relative changes with accelerometers, and correlate relative changes at the target, then one can directly relate one to the other, and their relative contributions to the overall shot process.


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## theminoritydude (Feb 11, 2013)

Roboto, I believe your data while accurate, is not meaningful, unless a larger picture of the state of the bow is painted. Other than the linear positions of the bow during the stroke, more accelerometers should be placed to take measurements from other points, so when the data is put together, would give you the angular movement of the bow, which is a better gauge of what the performance of your stabilization system is doing.


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## Mr. Roboto (Jul 13, 2012)

Look and you will find, knock and the door will be opened, and ask and you shall receive.

Here is angular acceleration data. Here is the angular acceleration about the vertical (z-axis). I placed two accelerometers 2.4 inches apart, and centered around the plunger. By taking the difference between the two accelerometers, dividing out the distance between them, one can get an estimate of the angular acceleration. As you can see, there isn't a lot of difference between the with and the without stab test cases.


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## theminoritydude (Feb 11, 2013)

Do you also have the groups of the arrows from the two different configurations?


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## theminoritydude (Feb 11, 2013)

I would like to bring your attention to the data points in the range between 0.05 - 0.055. Just before separation.
What is your evaluation of the data?


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## equilibrium (Oct 31, 2006)

Phewwww...after reading all that. Now I know why I shoot well....there's nothing in my head. I think, I've been demoted to using crayolas...again.


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## Mr. Roboto (Jul 13, 2012)

theminoritydude said:


> Do you also have the groups of the arrows from the two different configurations?


I don't have any shot group data. They were shot against a blank bale.

I would like to do this with someone shooting at a target down range so we can see how the riser data compares with actual grouping. But I can't be the archer for those experiments. Like I said, I am not very good. We would need to recruit someone that is an accomplished archer, and set up the tests on their equipment.

But yes, that is a necessary step.


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## Mr. Roboto (Jul 13, 2012)

theminoritydude said:


> I would like to bring your attention to the data points in the range between 0.05 - 0.055. Just before separation.
> What is your evaluation of the data?


I agree, there is a change there, and it is with the last third of the arrow travel before breaking loose of the string. Hard to say why that is different, but it is. Magnitude isn't that big of a change.

What I would like to do is sync video with accelerometer data so we can visualize how accelerometer data correlates with arrow trajectory.

I don't have answers to all these questions, I am just collecting data right now and will post what I learn along the way, along with my interpretation (if any) of the data. If my interpretations are, wrong, then I am open to correction. This is a journey.


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## Mr. Roboto (Jul 13, 2012)

equilibrium said:


> Phewwww...after reading all that. Now I know why I shoot well....there's nothing in my head. I think, I've been demoted to using crayolas...again.


This is why Dan always tells me to quite thinking about shooting and just shoot the arrow with various colorful adjectives.


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## Warbow (Apr 18, 2006)

Hmm, can you put accelerometers on your draw hand? Not sure what it would tell you, but, heck, if you are looking for data to track...

I now you have to try to form some hypotheses to test...


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## grantmac (May 31, 2007)

Mr. Roboto said:


> I agree, there is a change there, and it is with the last third of the arrow travel before breaking loose of the string. Hard to say why that is different, but it is. Magnitude isn't that big of a change.
> 
> What I would like to do is sync video with accelerometer data so we can visualize how accelerometer data correlates with arrow trajectory.
> 
> I don't have answers to all these questions, I am just collecting data right now and will post what I learn along the way, along with my interpretation (if any) of the data. If my interpretations are, wrong, then I am open to correction. This is a journey.


Last third of the nock travel should be when the stab has had the most effect to my thinking. 

Could you not mount the accelerometer to the end of the stab to get more precise measurements? 
In much the same way three lazers and three relatively simple cameras could have the resolution to produce useful data for visual comparison. 

Grant


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## b0w_bender (Apr 30, 2006)

equilibrium said:


> Phewwww...after reading all that. Now I know why I shoot well....there's nothing in my head. I think, I've been demoted to using crayolas...again.


Now that right there is funny! and you are also making a good point do we need any more proof of stabilization? 

Actually that was kind of the point of the original video was to make it obvious to the crayola crowd exactly what a stabilizer does. You know, people ask us _"are stabilizers really that important or how much of a difference does a stabilizer really make?"_, so I was trying to make it as obvious as possible that yes they make a difference. The next obvious question is, "well if it does that for aiming what does it do for the stabilizing of the riser during shot execution?". The resulting dialog is a good indication that perhaps it isn't as easy to answer as the aiming improvement question was to answer. Or I should say it isn't as easy to demonstrate the affect.

I'm an intuitive thinker so it was easy for me to extrapolate that the dramatic and obvious difference we see in aiming has to also translate to the motion of the riser during shot execution. I didn't need anymore data than that to confirm the stabilizers value. However I understand when others want or feel compelled to dig a bit deeper in the hopes of demonstrating the same sort of affect during the shot.

I think the overall similarities in the accelerameter data seems to have obscured the picture. We expected to see a huge difference like we did in the video. It cannot be as dramatic as the laser pointer video simply because we are measuring at the riser. With the laser pointer we are measuring the acceleration of the riser by using a weightless, perfectly straight bar of light sticking out of the front of the bow. Because this bar of light is bolted to the riser any riser movement is translated across it's entire length. Given it is 20 yards long and perfectly straight it amplifies the affect to a point where it is obvious to everyone what is happening. With the accelerameters the difference in the risers deflection is there it's just a lot harder to recognize. It isn't an intuitive demonstration that everyone can simply accept.

Lets zoom in a little to that part where the arrow looses it's connection with the string. Several people have mentioned it as being between .05 and .55. This eliminates all that other noise that is going on and obscuring the differences between the two measurements.

This is the the graphs along the Y axis I think it is real obvious the oscillations are slower and and less pronounced with the stabilizer

*without Stab . . . . . . With Stab *






. . . . .









This is the angular data we see the same thing the oscillations are more spread apart and significantly smaller with the stabilizer

*without Stab . . . . . . With Stab* 






. . . . .








Do you still need more data to believe that there is a measurable difference between the two?


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## Luke Cool (Oct 16, 2015)

Good video, but just adding weight does the same thing.
The more weight you add and the farther it is from the center of mass, the greater the effect you saw in the video.
This is simple physics. Look at a pendulum. 
If you add weight to it, it slows down. 
If you move the weight farther from the pivot point, it slows down more drastically.
On a compound bow, you get the same effect when you add weight, but especially if you move this weight a distance from the vertical center.
This video shows what happens when aiming. Someone in this thread ask "what does the stabilizer do while the bow is accelerating the arrow?"
That's easy to answer, it stabilizes the bow.

As the bow is accelerating the arrow, if the rest or D-Loop is misaligned, the cable rod (and the knock) will jump in the direction of the misalignment. This is called “launch torque”. The bow does this because the arrow pushes on the bow just as hard as the bow pushes the arrow. If the draw force’s thrust vector is perfectly centered behind the arrow, there will be no launch torque. A launch through a poorly adjusted rest causes a quick twisting movement, and a launch from a poorly adjusted D-loop causes a quick unequal movement in the limbs (one will jump back more than the other). The back end of the arrow will be pushed in that direction as it leaves the string. During a release, on a correctly adjusted bow, the bow will jump straight back. 

Most of the horizontal weight on a compound bow is close to the center of mass. A long stabilizer fixes this problem by putting a weight, and shock dampening material, in front and a ways away from the center of mass. It not only improves horizontal torque resistance by making quick twisting movements a great deal more difficult, it dampens the shock of the jump caused by the acceleration. In short, a stabilizer helps prevent torque caused by things like how the bow is held and imperfections in the "D-Loop and rest" alignment, and it gives the arrow a more solid stable base to launch from.

A balancing system- On a right handed bow, the right side of the bow weighs a lot more than the left side. A balancing weight system adjusts the center of mass of the bow to where the bow stays upright in your hand naturally. Having to twist your hold to keep the bow upright applies unwanted torque to an arrow’s release. Just like the stabilizer, the more weight you add and the farther it is from the center of mass, the more forgiving your bow will become. Also, during the launch, the bow will begin to tilt in the direction that it is heaviest. A balancing system prevents this effect. For hunting, the ideal system adds as little weight as possible to achieve a good balance. If you did a good job balancing the bow, the rest adjustment will be very close to the center line of the bow.


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## Luke Cool (Oct 16, 2015)

And someone said that the arrow takes 15ms to launch. It's good guess, but it's a ways off.
The launch time depends on the bow, its settings, and the weight of the arrow.


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## Mr. Roboto (Jul 13, 2012)

That is a compound, totally different beast. Arrow speed, and time to launch, is a function of bow type, draw weight, and the mass of the arrow. 15 ms is more for a recurve in the #45 draw weight range. 

But the above video is an interesting one. A recurve that takes 15ms to launch an arrow, and the above compounds take less than 1ms, which bow will benefit more from a stabilizer during the power stroke?


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## Luke Cool (Oct 16, 2015)

Mr. Roboto said:


> That is a compound, totally different beast. Which bow will benefit more from a stabilizer during the power stroke?


A stabilizer performs the same function on both bows. But the compound bow would benefit more, because the power stroke is longer and stronger.
Some of the less powerful youth compound bows don't even have a pervision for a stabilizer because there is almost no benefit to having one.
You can argue that the arrow spends more time in the recurve, but I still think I'm right.


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## Luke Cool (Oct 16, 2015)

Mr. Roboto said:


> That is a compound, totally different beast. Arrow speed, and time to launch, is a function of bow type, draw weight, and the mass of the arrow. 15 ms is more for a recurve in the #45 draw weight range.
> But the above video is an interesting one. A recurve that takes 15ms to launch an arrow, and the above compounds take less than 1ms, which bow will benefit more from a stabilizer during the power stroke?


In the post you were referring to, I said "The launch time depends on the bow, its settings, and the weight of the arrow."
You said "Arrow speed, and time to launch, is a function of bow type, draw weight, and the mass of the arrow."
The two compound bows you saw in the video were the same type of bow, yet have different launch times.
Traditional bows (of the same weight) will have competitively similar launch times. 
But, because of its cam configuration, one compound bow's launch time might be drastically different from another.
If you would have left the word "type" out of your post, I concur with you statement.
Arrow speed, and time to launch, is a function of the bow, its draw weight, and the mass of the arrow.


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## Luke Cool (Oct 16, 2015)

I also used the word "sittings" because there are adjustments that you can make to a compound bow that will change the launch time. 
Settings, like the back wall, string position, draw length, draw weight, and the let-off can be adjusted on some compound bows.
Just saying "draw weight" comes up a bit short. I can tell that you are of a "Traditional bow" mind set.


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## adamstephens (Mar 5, 2012)

Vittorio said:


> Yes,fun, but exactly what had to be expected, and thanks for the detailed measure of it.
> 
> The stabilizing system should also contribute to the stability of the riser during the travel of the nock attached to the string , and of course here we go to the distribution of the weight in the stab system and the mass (lateral inertia) of the stabilized riser at the release. Adding just a long rod to the riser makes thing better for aiming and longitudinal stability, but not so much in lateral /torsional stability. There the short side rods and their balnce come into effect. Or, in BB how you adjust the weights (not on front, only)


Vittorio

How do you adjust weights for BB?

Adam


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## b0w_bender (Apr 30, 2006)

Luke Cool said:


> A stabilizer performs the same function on both bows. But the compound bow would benefit more, because the power stroke is longer and stronger.
> Some of the less powerful youth compound bows don't even have a pervision for a stabilizer because there is almost no benefit to having one.
> You can argue that the arrow spends more time in the recurve, but I still think I'm right.


I disagree I think that a recurve would benefit far more because the arrow is attached to the bow\bowstring string for a lot longer time. A stable platform becomes a lot more important if it has a longer time to affect the shot. Also when shooting a recurve because of the finger release you get a lot of lateral motion introduced into the bow\bowstring. A compound with a release is typically driving the force directly inline with the nock or as close as the archer can get it. So the arrow travels in a much more liner motion. You yourself agreed that the launch time is much earlier with a compound. So the arrow is in contact with the bow\bowstring for a lot less time with a compound. In fact that was the whole point of the video you posted, Their point is: a bow that releases the arrow faster is likely to be more accurate because you reduce the time the bows movement can affect the arrow. Anyway, I believe Mr. Robato's point was that he was using a recurve because it should be easier to see and record the benefit a stabilizer has precisely because of the longer duration in the power stroke. 

Because there is a lot of JOAD folks and Olympic style coaches on this forum you'll find that most of the participants only have a minor interest in compounds. I suspect that is another reason why Mr. Robato was using a recurve to test the motion of the riser during the shot execution. It's also why everyone else just assumed he was talking about a recurve in his posts.


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## Luke Cool (Oct 16, 2015)

b0w_bender said:


> I disagree I think that a recurve would benefit far more because the arrow is attached to the bow\bowstring string for a lot longer time. A stable platform becomes a lot more important if it has a longer time to affect the shot. Also when shooting a recurve because of the finger release you get a lot of lateral motion introduced into the bow\bowstring. A compound with a release is typically driving the force directly inline with the nock or as close as the archer can get it. So the arrow travels in a much more liner motion. You yourself agreed that the launch time is much earlier with a compound. So the arrow is in contact with the bow\bowstring for a lot less time with a compound. In fact that was the whole point of the video you posted, Their point is: a bow that releases the arrow faster is likely to be more accurate because you reduce the time the bows movement can affect the arrow. Anyway, I believe Mr. Robato's point was that he was using a recurve because it should be easier to see and record the benefit a stabilizer has precisely because of the longer duration in the power stroke.
> 
> Because there is a lot of JOAD folks and Olympic style coaches on this forum you'll find that most of the participants only have a minor interest in compounds. I suspect that is another reason why Mr. Robato was using a recurve to test the motion of the riser during the shot execution. It's also why everyone else just assumed he was talking about a recurve in his posts.


You missed two things. The bow shown in the video was an old compound bow with a 50% let-off, he even stated so,, not a recurve. The other point you missed is "bow weight". On two similar bows at the same draw poundage, the lighter one of the two will benefit the most by adding a stabilizer. The same can be said about launch time and draw poundage if you isolate them as the only variable, but on brace height, this is not universally true. I believe, at a certain point, the draw poundage gets to a level to where the forces overwhelm launch time and bow weight. An aggressive cam will keep a compound bow at 70 pounds during almost half of its draw cycle. That is a lot of energy, way over twice what a 70 pound recurve is capable of. 

There so many variables at play here that I do not believe ether one of us is completely right or wrong. He ask "Which bow will benefit more from a stabilizer during the power stroke?"
We will all agree that "bow weight, launch time and draw poundage" are important factors, but I do not believe that there is a universally perfect answer.

Side note; The energy vs speed thing will graph as a curve, it is not linier. My car at 250 HP will go 140mph. A Bugatti Veyron at 1200 HP will go 252mph.


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## Luke Cool (Oct 16, 2015)

A stabilizers job is to tame energy during the aim and launch of an arrow, and favorably adjust the bow’s weight distribution.
Mostly, only recurves that use sights even have previsions to mount a stabilizer.
That being said, on the recurves that can use one, it appears that they are used mostly for there aim stabilization and weight distribution properties.
The majority of recurves do not have stabilizers, most compound bows do.


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## Halfcawkt (Dec 27, 2015)

I have often wandered what the measurable difference would be. Thank you for your well illustrated demo, sir. I truly found it very helpful to understand to what extent it aided the shooter.


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## b0w_bender (Apr 30, 2006)

Luke Cool said:


> he even stated so,, not a recurve.


"He" is me, I assure you I didn't miss it, I'm pretty sure I know what I was holding. I chose a compound because there are more compound shooters and it's always best if a video relates to the masses. However talking compounds in this forum tends not to be very fertile soil and so until you started your post, the focus and testing was related to recurve shooting. Since I shoot everything I'm game to talk about anything. 

If you want me to stipulate that both bows are the same weight fine in my above scenario they are the same weight. Please address the lateral movement and the inconsistencies of forces you get from a finger release vs the consistent inline forces you see with a mechanical release. Also please address the limb motion of a parallel limbed compound with that of a recurve, which one jumps in your hand more? If you still think that the riser of a compounds shot with a mechanical release is more prone to inconsistent movement during the shot cycle then I think you have some confirmation bias going on there.

Honestly I'm not completely convinced that stabilizers are significantly relevant during the shot cycle with any bow. I say that because inaccuracy comes from inconsistencies. So yes a bow does bounce and flex during the shot cycle but if the forces are the same every time that bouncing and flexing will also be the same from shot to shot. That means if a stabilizer does have an affect then it would be to minimize the affects of force variances. We see incredible consistency during the power stroke particularly with a mechanical release. I think where most archers struggle is in the aiming and alignment and not in those few milliseconds of the power stroke. This is why I think the aiming benefits you get from a stabilizer far out weighs anything the stabilizer is doing during the power-stroke. 

if you were to use a shooting machine to test the accuracy of a bow with and without a stabilizer I suspect the scores would *NOT* be statistically different. (It would be a good test) If a shooting machine can shoot as well with and without a stabilizer it would be because there is very little variance in the system. It's only the variances from shot to shot that a stabilizer could possibly help with. I think we can agree that a compound of any type shot with a mechanical release has far less variances than does a recurve shot with a finger release? So since you can't possibly be arguing that a compound has less consistency, I believe what you are saying is that based on the additional energy being applied to the arrow from a compound any variances that are applied become amplified. They would need to be as numerous and amplified to a greater level than the variances we see in shooting a recurve with fingers. ( I doubt it but...) We would probably need a shooting machine that is capable of introducing measurable variances to prove that point. 

Here is another interesting thought who would score better an archer with a compound and no stabilizer or a recurve shooter with stabilizer?


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## BrokenLimbs (Nov 25, 2008)

Interesting video. Exactly what I had suspected when I saw this thread.

Stabs are all about "pin float management" to me. And as eyes "age" (and other things lol) a stabilizer probably becomes more relevant too. (Primarily because of pin float in combination with the reading glasses/fuzzy pin thing etc.)
(And of course if someone is "over-bowed" a stab would presumably compensate in some ways. But drawing too much poundage is a bad thing in the first place! ~ So don't add a stab to try and get away with being "over-bowed.")

I also suspect that some "problem bows" (excessive riser/roller torque effecting the shot etc.) might really benefit from an effective (long & most weight at the end) stabilizer. ~ I can't help but wonder whether using one might have compensated for problems that developed with my 2008 Admiral. (The thought never occurred to me back then.) Prior to this past fall, I had never used/benefited or believed in adding a stabilizer on my hunting bows. I recently added one to my Chill-R. (Hunting/shot opportunities are seldom over 40 yards here in the northeast, so I never saw any benefits prior to struggling with pin fuzziness.) Regardless, the addition of this stabilizer last fall got me wondering what the effects of adding one to that "problem bow" might have been.


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## Kaylish (Dec 22, 2015)

tagged for further reading


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## Luke Cool (Oct 16, 2015)

b0w_bender said:


> "
> 
> If you want me to stipulate that both bows are the same weight fine in my above scenario they are the same weight. Please address the lateral movement and the inconsistencies of forces you get from a finger release vs the consistent inline forces you see with a mechanical release. Also please address the limb motion of a parallel limbed compound with that of a recurve, which one jumps in your hand more? If you still think that the riser of a compounds shot with a mechanical release is more prone to inconsistent movement during the shot cycle then I think you have some confirmation bias going on there.
> 
> ...


Honestly I'm completely convinced that stabilizers are relevant during the shot cycle with any bow that has a significant amount of power.
A friend bought a PSE Rally "bear bow". At lower power, it was fine at 50 pounds. At 60 pounds, with a 360 grain arrow, it sounded almost as bad as a dry fire. 
A stabilizer and string stop fix the problem. I read some reviews, and left unfixed, it would destroy the string. 
On a speed bow, the string will last longer if a good shock dampening stabilizer is installed.
Do stabilizers help during the shot cycle? They provide a more forgiving base to lunch from in two ways.
1) The less effort it takes to hold the bow upright and steady, the less torque that will be introduced to the handle.
2) If the shock dampening fetcher is so unimportant, why is it so popular? It is used purely on the shot cycle.
Noise is one reason, you can find the other reason by using a dead blow hammer. 
A bow reshapes and deforms as the stresses on it change during the draw and release. The "dead blow" effect minimizes this influence on the release.
And the shock dampening fetcher and its weight being a distance from the center line does make a significant difference on slightly detuned powerful bows. 
On a well tuned bow, a stabilizer will not make a significant difference at the closer ranges.
And on a low powered bow, a stabilizer will have little to no relevance during shot cycle. 

Who would score better, an archer with a compound and no stabilizer, or a recurve shooter with stabilizer?
If he has a sight, probably the recurve shooter with stabilizer. But we are back to the same game, the answer is not so cut and dried.
The mechanical release vs hand release would be another variable, because some recurve shooters do use a mechanical release.


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## kshet26 (Dec 20, 2010)

There clearly is evidence that that stabilizers have an effect during the shot cycle based on examples where the same shooter with the same bow will need a weaker arrow when shooting barebow. Watching the Joe Thornton video I saw this. 

It's clear to me that the rotation of the bow induced by a finger release is resisted by the addition of a long stabilizer. As was mentioned before, the resolution in measurement probably isn't high enough to appreciate that even a lateral movement of 2mm of the nock between a stabilized bow and a non-stabilized bow can mean the difference between an arrow in the gold and an arrow in the blue at 70 mm.

I think of stabs like fletchings. They won't prevent you from missing the target if you aim poorly... they just smooth out inconsistencies. A bareshaft and a barebow can both shoot X's at 70m.


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## Ms.Speedmaster (Dec 10, 2010)

adamstephens said:


> Vittorio
> 
> How do you adjust weights for BB?
> 
> Adam


Not wanting to answer for Vittorio, but there are many options with riser inserts, external mounted weights, weighted riser covers... 

We're about to embark on a BB weight science project at X10 Archery, using my Gillo. 
The laser pointer just arrived.


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## b0w_bender (Apr 30, 2006)

Luke Cool said:


> Honestly I'm completely convinced that stabilizers are relevant during the shot cycle with any bow that has a significant amount of power.
> A friend bought a PSE Rally "bear bow". At lower power, it was fine at 50 pounds. At 60 pounds, with a 360 grain arrow, it sounded almost as bad as a dry fire.
> A stabilizer and string stop fix the problem. I read some reviews, and left unfixed, it would destroy the string.
> On a speed bow, the string will last longer if a good shock dampening stabilizer is installed.
> ...


Yup I agree the stabilizer does help with vibration dampening with or without a rubber absorbing doodad. I agree, Yes those have value in both comfort and feel. But the majority of vibration is post shot so not an accuracy concern. Also as a point of clarity stabilizers may help during the power stroke I just would like to see the evidence because I'm not convinced. Without question the improvement with aiming is overwhelmingly better and really it's enough to convince anyone not interested in shooting in the barebow\trad divisions to bolt one on. I just wonder if the aiming and comfort, reduced vibration and balance we get with a stabilizer is explaining the better scores and the stabilization within the 5 to 15 millisecond power stroke is of minimal value. 



Luke Cool said:


> because some recurve shooters do use a mechanical release.


Only if they don't know what they are doing. There are no recurve only divisions that allow for mechanical releases so if you shoot a release you would be competing against compounds. I've only seen one person in my 30 years of shooting and coaching seriously using a release with a recurve. After I explained the competitive concerns he switched to fingers on the recurve and bought a compound for his release.


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## Luke Cool (Oct 16, 2015)

b0w_bender said:


> Yup I agree the stabilizer does help with vibration dampening with or without a rubber absorbing doodad. I agree, Yes those have value in both comfort and feel. But the majority of vibration is post shot so not an accuracy concern. Also as a point of clarity stabilizers may help during the power stroke I just would like to see the evidence because I'm not convinced. Without question the improvement with aiming is overwhelmingly better and really it's enough to convince anyone not interested in shooting in the barebow\trad divisions to bolt one on. I just wonder if the aiming and comfort, reduced vibration and balance we get with a stabilizer is explaining the better scores and the stabilization within the 5 to 15 millisecond power stroke is of minimal value.


I have no proof other than my own keen instinct and experience. 



b0w_bender said:


> Only if they don't know what they are doing. There are no recurve only divisions that allow for mechanical releases so if you shoot a release you would be competing against compounds. I've only seen one person in my 30 years of shooting and coaching seriously using a release with a recurve. After I explained the competitive concerns he switched to fingers on the recurve and bought a compound for his release.


You are the expert on recurve bows, not me. In a comment about a YouTube video, I said there is no way to regulate the power of the draw on a recurve. A gentleman corrected me and said that they make clicker releases that click at a specific weight. I've never seen one, but it sounds reasonable. If releases are made that are specificly designed for use on a recurve, I assumed recurve releases have somewhat of a following. When I shot recurve bows many years ago, I doubt releases even existed.


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