# Hybrid band



## orion25 (Nov 10, 2021)

Hello friends,

I carefully analyzed the two excellent posts "Catapult Bands Demystified: It's Physics!" And "Tapered Flatbands - Mechanism and Effect". I also did conical strip elongation tests in order to understand their behavior. After some thought, I think that it is possible to improve the efficiency of the bands by making a band with a straight part and a tapered part.

The data shows that the initial impulse is maximum during the first 4 ms, The basic idea is to take advantage of the acceleration impulse of the conical band during the first 4 ms and to accumulate the acceleration of the right band for the remaining 25 ms. If this idea works, it will be possible to reach 81ms with the data available in these posts.
Tape elongation tests show that 50% of the tape length has an elongation rate less than or equal to the overall tape elongation rate.










Not having the data, I reconstructed the graph and applied the idea above.










The difficulty lies in finding the right balance between straight and conical. I modified a 12x7x140 conical strip set to 9.5x9.5x70 + 9.5x7x70 hybrid. As the right part of the hybrid band will stretch more than on a tapered band, I cut 10mm of the straight part to try to find the same force to stretch the tapered part.










Not having a chrony to check the difference in speed, I carried out an impact test in a can of sardines with 6mm beads.
Conical band: 3.3mm deep
Hybrid band: 3.9mm deep

It seems that the energy gain is real. I did an endurance test on a hybrid set to check the life of the tapes. I am currently at 640 shots and everything is ok.

I would like to ask if any volunteers with a chrony to do speed tests with this modification.Thank you in advance for future volunteers.

Have good days;


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## Whytey (Sep 26, 2021)

Very interesting..... pic of the actual cut band?


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## Valery (Jan 2, 2020)

Something similar is offered by the Chinese. Maybe it works. We have to try it.


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## Booral121 (Jan 6, 2019)

Been tried .guys in the UK used and reviewed the Chinese ones .and from what I remember there was no gain in doing it .👌🎯👍


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## orion25 (Nov 10, 2021)

Not easy to see in the photo because the cone is 9x7.


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## orion25 (Nov 10, 2021)

Valery said:


> Something similar is offered by the Chinese. Maybe it works. We have to try it.
> View attachment 358689
> View attachment 358690


Can you send me the link please.


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## Valery (Jan 2, 2020)

orion25 said:


> Can you send me the link please.


Sure, here:


https://slingshooting.com/gmbw-flat-band-cutting-template-high-quality-of-acrylic-boardfully-customizable-as-per-your-requirment/


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## orion25 (Nov 10, 2021)

Valery said:


> Sure, here:
> 
> 
> https://slingshooting.com/gmbw-flat-band-cutting-template-high-quality-of-acrylic-boardfully-customizable-as-per-your-requirment/


Thanks you Valery,


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## 43844 (Jun 1, 2020)

orion25 said:


> Hello friends,
> 
> I carefully analyzed the two excellent posts "Catapult Bands Demystified: It's Physics!" And "Tapered Flatbands - Mechanism and Effect". I also did conical strip elongation tests in order to understand their behavior. After some thought, I think that it is possible to improve the efficiency of the bands by making a band with a straight part and a tapered part.
> 
> ...


You might get a better record if you used balistic gell for the test, using the same brand new bands and climate conditions.

The end result is penetration.


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## madmax96 (Sep 27, 2021)

guys might want to take a look at this, maybe it helps


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## Valery (Jan 2, 2020)

madmax96 said:


> guys might want to take a look at this, maybe it helps


It worked for me!  There is an increase in speed, but so insignificant that the cost does not justify the result.


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## orion25 (Nov 10, 2021)

Hello friends,

Thank you for all those informations. I will continue down this path to see if it improves speed.

Have good days;


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## orion25 (Nov 10, 2021)

Hello friends,

After seeing the video, I think the 2 solutions are different. The solution of the video is equivalent to the solution of a tube assembly with loop. It seems that the parts before and after the cone are of equal length and the cone is relatively short, for me the cone serves as a transition between the wide strip and the narrow strip. In summary this solution and a wide straight strip, a short cone and a narrow straight strip.

The solution I suggest is a straight strip followed by a tapered strip. I am currently testing a strip of 10x10x90 and 10x7x75 active length 165mm, extension 800mm, overall rate of elongation 4.8, equivalent to a conical strip of 13x7x165. The hybrid band has a stronger impact than the conical belt but I think that we still have to optimize the straight / cone ratio to have the full potential of this solution.

This solution may not work as expected on paper and the gain obtained may be negligible.

Have good weekend


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## High Desert Flipper (Aug 29, 2020)

The "sharpened tapers" seem to be a similar idea. I got a few templates and tested them. I found they were indeed a bit more efdicient, but efdect I got was slightly rwdyced draw weight with similar speed from same dimension of taper when comparing steaight to sharpened tapers.

Since that time I have gotten a few more templates with more aggressive sharpened tapers. They arent a quantum leap that increases speed by 20%, but they are a bit more efficient and I like them.









Sharpened tapers, maybe something different from the hype.


I know I write long posts so I will try to break this up into a few less onerous chunks. I was curious to try "sharpened" vs regular tapers so collected a bunch of data. I will put summarized data for most tests up on this thread. I collected and am part way through analyzing a good pile of...




www.slingshotforum.com


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## orion25 (Nov 10, 2021)

Hello friends,

Here is the impact comparison between a conical band and an optimized hybrid strip made from the conical band. See explanation above. I think it is possible to further optimize the hybrid band but the result is already satisfactory and seems to confirm this solution.  










Have good days;


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## orion25 (Nov 10, 2021)

High Desert Flipper said:


> The "sharpened tapers" seem to be a similar idea. I got a few templates and tested them. I found they were indeed a bit more efdicient, but efdect I got was slightly rwdyced draw weight with similar speed from same dimension of taper when comparing steaight to sharpened tapers.
> 
> Since that time I have gotten a few more templates with more aggressive sharpened tapers. They arent a quantum leap that increases speed by 20%, but they are a bit more efficient and I like them.
> 
> ...


 Thank you for your answers,

But the two solutions are different. I said :

"The data shows that the initial impulse is maximum during the first 4 ms, The basic idea is to take advantage of the acceleration impulse of the conical band during the first 4 ms and to accumulate the acceleration of the right band for the remaining 25 ms. If this idea works, it will be possible to reach 81ms with the data available in these posts."

"After watching the video, I think the 2 solutions are different. The solution of the video is equivalent to the solution of a tube assembly with loop. It seems that the parts before and after the cone are of equal length and the cone is relatively short, for me the cone serves as a transition between the wide band and the narrow band. In summary this solution is a wide straight band, a short cone and a narrow straight band."

See first post.


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## High Desert Flipper (Aug 29, 2020)

I can never pass on the opoirtunity to play. I will likely make some straight, sharpened, and compare them to the hybrid taper you descibed here. It should be a lot of fun to test them on the chrony. I am tied up for a bit but stay tuned...


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## orion25 (Nov 10, 2021)

High Desert Flipper said:


> I can never pass on the opoirtunity to play. I will likely make some straight, sharpened, and compare them to the hybrid taper you descibed here. It should be a lot of fun to test them on the chrony. I am tied up for a bit but stay tuned...


OK no problem, I have time. For information, I shortened the tape described above by 5mm before testing on the can of sardines, so my hybrid band is Precise 0.45, 10x10x85 + 10x7x75, active length 160mm, extension 800, stretch rate 5, ammo 6mm steel, distance reach 8.40m,.

following the quick calculations made and the little cumulative experience, I think the right solution is about 50/50 cone / straight. I estimate the speed gain at around 12% but without a Chrony it's difficult to verify.

I think you have to cut the conical strip straight strip from the middle of its length and shorten it in 5mm increments checking the speed obtained at each increment.

The principle is that the straight part of the belt produces the same force on the remaining conical part as before the modification to hybrid belt. Normally we will accumulate the acceleration of 4 ms of the conical band and the acceleration of the straight band over the rest of the time. All this is only theoretical, based on simplified calculations and on intuition as much to say about few things. I don't think this solution is faster than a very tapered conical strip but it may be worth testing as well. 

I am at your disposal if you need any other information. For my part, I did an endurance test of my hybrid group with a goal of 1000 shots minimum. thank you in advance for your help.


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## orion25 (Nov 10, 2021)

Hello friends,

Tape break after 560 shots. A cut formed at the edge of the handcuff. To note this is the second case . I resume an endurance test without handcuffs. To be continued.

Have good days;


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## orion25 (Nov 10, 2021)

After breaking the first hybrid tape in the endurance test, I tested several setups from a 12.5x7x160 taper tape? I cut one side of this strip to get the hybrid strips below:

hybrid band 11x7 7030 (tapered/straight en %)
hybrid band 10x7 5050
hybrid band 9x7 4060

the first two bands do not give a good result on the puncture test, the third band perforates the box without difficulty. The pulling force of the 9x7 4060 hybrid band is 7.05 lbs, elongation rate 4,97.

The speed measurements are carried out by the sound method with AUDACITY over a firing distance of 8.4m with a recorder in the middle of the trajectory on three shoots.

T1 = 92 m/s
T2 = 91 m/s
T3 = 95 m/s

Even if the measurement method is not perfect, it seems to confirm the potential of the hybrid band in 4060. I am doing the endurance test of this band, I will give the result as soon as possible. 

Next goal, check other mixed tapered / straight in order to find the best configuration.


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## orion25 (Nov 10, 2021)

The tape broke 200 shots at the ligature. As mentioned in a Post on this forum, it seems like speed kills the tapes.
Manufacturing of a new slower band:
Feature: PRECISE Hybrid Belt 0.45 8x6 4060 -> Ba = 160 -> Al = 760 -> Ta = 4.75 → Ft = 4.47 lb -> 2.03 kg -> V = 233 Fps


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## orion25 (Nov 10, 2021)

Hello friends,

Following an error in the speed calculation which did not include the sound return time to the recorder, here are the speeds measured for the 8x6 4060 tape with 1/4 steel.










Good day;


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## orion25 (Nov 10, 2021)

Here is the tape speed reading after 460 shots. The speed dropped by 8 m / s.










The tape set broke at 730 hits. I will try the following setup: 9x7 4060 in PRECISE 0.65 with a stretch ratio of 4.5.


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## Valery (Jan 2, 2020)

I dusted off the chronograph for fun.  
Precise 0.45, 20x10 taper, 1/4 steel ball,
Average speed of 92 m/s (301.8 fps). 
Finally convinced that the usual cones work fine.


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## Whytey (Sep 26, 2021)

Valery said:


> I dusted off the chronograph for fun.
> Precise 0.45, 20x10 taper, 1/4 steel ball,
> Average speed of 92 m/s (301.8 fps).
> Finally convinced that the usual cones work fine.


Is cones just another name for tapered bands?
Apologies from a greenish newbie.


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## orion25 (Nov 10, 2021)

Valery said:


> I dusted off the chronograph for fun.
> Precise 0.45, 20x10 taper, 1/4 steel ball,
> Average speed of 92 m/s (301.8 fps).
> Finally convinced that the usual cones work fine.


You have reason, the cones are the best solution for the moment which does not prevent us from looking for another solution.

Can you tell me the other parameters during your test, tape length, your elongation, stretch rate, tensile strength, ... in order to better compare the results.

Thanks you in advance;


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## orion25 (Nov 10, 2021)

Following the test, the 9x7 band is 9m / s slower than the 8x6 band, more rubber does not mean more speed!










a 7x5 tape is 5m / s slower than the 8x6 tape, it seems that the 8x6 4060 is the best option at the moment. Next test with unbranded 0.35 latex.


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## orion25 (Nov 10, 2021)

Whytey said:


> Is cones just another name for tapered bands?
> Apologies from a greenish newbie.


Yes it is the same shape of band.


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## Valery (Jan 2, 2020)

Whytey said:


> Is cones just another name for tapered bands?


Yes. 


orion25 said:


> Can you tell me the other parameters during your test, tape length, your elongation, stretch rate, tensile strength, ... in order to better compare the results


I should add that the working length of the band is 6.5 inches, the extension is 32 inches (fivefold extension), I do not measure the stretching force, I have two parameters - "comfortable" and "uncomfortable"  
I don't count the number of shots before the tapes break either.


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## orion25 (Nov 10, 2021)

Valery said:


> Oui.
> 
> Je dois ajouter que la longueur de travail de la bande est de 6,5 pouces, l'extension est de 32 pouces (extension quintuple), je ne mesure pas la force d'étirement, j'ai deux paramètres - "confortable" et "inconfortable"
> Je ne compte pas non plus le nombre de plans avant la rupture des bandes.
> ...


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## orion25 (Nov 10, 2021)

Valery said:


> I dusted off the chronograph for fun.
> Precise 0.45, 20x10 taper, 1/4 steel ball,
> Average speed of 92 m/s (301.8 fps).
> Finally convinced that the usual cones work fine.


How far do you measure the speed?


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## Valery (Jan 2, 2020)

orion25 said:


> How far do you measure the speed?


On the way out of the slingshot. 
I hold the slingshot about 20 inches from the chronograph.


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## orion25 (Nov 10, 2021)

Valery said:


> On the way out of the slingshot.
> I hold the slingshot about 20 inches from the chronograph.


Thanks for the info , my speeds are not directly comparable because they are measured by the sound method over a distance of 8.4m. It is therefore the average of the initial speed with the speed at 8.4m provided that the loss of speed is linear over the distance, and moreover, they integrate the acceleration phase in the slingshot.
For the moment this serves as a reference to compare my different configurations and I will correct the formula to bring it as close as possible to a stopwatch measurement at 4.2m. I can also evaluate the initial speed with an Airsoft software that I use to trace the trajectory for the definition of my optical sight.


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## Valery (Jan 2, 2020)

orion25 said:


> It is therefore the average of the initial speed with the speed at 8.4m provided that the loss of speed is linear over the distance, and moreover, they integrate the acceleration phase in the slingshot.


Am I correct in assuming that it measures the time between the tape clicking and the click of the hit on the target? Would it make sense to place paper sheets at the beginning and end of the course? There would be about an equal amount of sound wave when the sheets are punched through.
And the velocity drop of the projectile over the distance can be considered linear. For a rifle, it is assumed that for each meter of distance, the velocity drops by 1 m/s. I think the same would be true for a slingshot.


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## orion25 (Nov 10, 2021)

Valery said:


> Am I correct in assuming that it measures the time between the tape clicking and the click of the hit on the target? Would it make sense to place paper sheets at the beginning and end of the course? There would be about an equal amount of sound wave when the sheets are punched through.
> And the velocity drop of the projectile over the distance can be considered linear. For a rifle, it is assumed that for each meter of distance, the velocity drops by 1 m/s. I think the same would be true for a slingshot.


Thank you for your propositions. I checked, the speed loss for a 6 mm ball of 0.9 gr is 0.61 m / s per meter. I integrate this parameter in the formula as well as the acceleration time. With these corrections the initial speed values are comparable with the values of a chrono. Here are the updated values.










In the near future, I will be making comparisons of the hybrid band with the straight and tapered and see if I should continue in that direction.


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