# Taper By Perforation



## Charles

Yep ... I know ... I should be cleaning up my studio and framing some of my prints. But I am having fun today, so I decided to try something I have been thinking about for some time.

I think we are all impressed by the speed increases possible with tapered bands. I was thinking about that ... and about the prospect of doubling Alliance 105s or 107s for half their length to achieve a tapered effect. But then I got to thinking more about it. The speculation is that by tapering the bands, you have a lighter part of the band toward the pouch, which gets the greatest acceleration.

Now, bear with me a moment. Have you ever watched a plumber or an electrician install lines in a basement? When he (sorry, the vast majority of plumbers and electricians are male) comes to a floor joist, he does NOT notch it to allow the line to pass. Notching a timber weakens it significantly. Rather, he drills a hole through the joist. Test by all sorts of agencies have shown that drilling a hole through the middle does not significantly reduce the strength of a joist. Soooo, says I, why not do the same thing with a slingshot band ...










I used a ball point pen and a ruller to lay out a center line on the bands on my PFS. I made a cross at each 1/4 inch. Then I used my rotary punch and a 4mm bit to cut holes in the lower half of the band. Before the holes were punched, the bands were averaging 167 fps with 3/8 inch steel balls. After the holes were punched, with no other change in the setup, the average jumped to 175 fps. That is a 5% increase ... not too shaby! I have not had enough time to guage the effect on band life, but these results are promising.

What would happen if I used bigger holes? What would happen if I cut out a slot instead of punching holes? Well, these are all things one might try.

Cheers ...... Charles


----------



## NightKnight

Interesting! Keep us updated!


----------



## Papa G

very intresting, look forward to hearing more.


----------



## Ace

Hey Charles where do you get your 107s? I can't seem to find any here on the lower mainland.


----------



## Charles

Ace said:


> Hey Charles where do you get your 107s? I can't seem to find any here on the lower mainland.


Hello Ace. I could not find them on Amazon.ca, nor on Staples.ca. In the end, I ordered them from the US through Amazon.com.

http://www.amazon.com/Alliance-Sterling-Ergonomically-Correct-25075/dp/B0017LR7CU/ref=sr_1_2?ie=UTF8&qid=1315353775&sr=8-2

With shipping and all, it doubled the cost. But I ordered a box of 107s and a box of 105s. I have not yet tried the 107s, as I do not need their length. I believe they are the same material as the 105s, just a bit longer.

I am in Victoria. Where on the lower mainland are you located? Are there any other sling shooters over there? Maybe we could organize a shoot some time.

Cheers ...... Charles


----------



## Ace

I'm in Burnaby the only shooters i know of are me and my friend.


----------



## Dayhiker

Charles, if that doesn't significantly decrease band life then it is a really BRILLIANT idea. Hat's off to ya matey!


----------



## Charles

Dayhiker said:


> Charles, if that doesn't significantly decrease band life then it is a really BRILLIANT idea. Hat's off to ya matey!


Yeah, I suppose ... But if it DOES significantly decrease band life, then am I just a dolt????























Cheers ..... Charles


----------



## e~shot

Looks interesting


----------



## strikewzen

every time you come up with an idea it's always extremely clever, why aren't you building rockets but pfs lol

thank you sir... for your contributions


----------



## Dayhiker

Charles said:


> Charles, if that doesn't significantly decrease band life then it is a really BRILLIANT idea. Hat's off to ya matey!


Yeah, I suppose ... But if it DOES significantly decrease band life, then am I just a dolt????























Cheers ..... Charles
[/quote]

Well, Charles, you've made me think. I am now in the unenviable position of having to decide whether a "brilliant" idea is still brilliant when it has proven itself impractical...
But to answer your question with a question: Did i ever actually say that you were NOT a dolt?


----------



## Charles

Dayhiker said:


> Charles, if that doesn't significantly decrease band life then it is a really BRILLIANT idea. Hat's off to ya matey!


Yeah, I suppose ... But if it DOES significantly decrease band life, then am I just a dolt????























Cheers ..... Charles
[/quote]

Well, Charles, you've made me think. I am now in the unenviable position of having to decide whether a "brilliant" idea is still brilliant when it has proven itself impractical...
But to answer your question with a question: Did i ever actually say that you were NOT a dolt?








[/quote]

Ya got me, big guy!!! My secret is out!






























Cheers ........ Charles


----------



## bj000

i think you are on to something here. i can't see how it will effect the band life too much . don't most rips happen at the pouch end? and usually not from the center of the bands, but at the edges.
i am willing to bet that we will all be doing this in the near future.


----------



## Dayhiker

Go ahead bj00, I'll wait in the car. . . (but I'll be watching)


----------



## Charles

Well, time for the bad news ... I guess I am a dolt after all!

I had punched 12 holes in the lower half of the bands. I decided to slot the last six holes ... I used my punch and a roller cutter to make the slots.










I then tested it out with the Chrony. I made 20 shots with 3/8 inch steel ball, and the average speed was a bit over 181 fps. Recall that the plain bands gave me 167 fps. So I got an increase in speed of 8% ... the holes alone gave me an increase of only 5%. So engineering extrapolation would suggest that if I did away with the bands altogether, I would get an infinite increase in speed!!!!









Now for the bad news. The bands broke on the 21st shot. It is interesting that they broke at one of the original perforations. Given that I had fired about 50 or 60 shots on the perforated bands yesterday, I would suggest that you could count on a band life of no more than 70 shots. Given that my other PFS with Alliance 105 bands now has over 400 shots on it, I would say that this method does significantly decrease band life. It seems that cutting the bands always introduces some weakness. For me, it is not worth the sacrifice in band life for a mere 8% increase in speed.

Cheers ..... Charles


----------



## bj000

i still think there is some tinkering to do here.


----------



## NightKnight

Oh, well. It was a great idea!


----------



## Dayhiker

I still think it was brilliant, Charles. Thanks for trying and sharing. You're a mensch.


----------



## NaturalFork

Wow. This is cool. The bands look great too.


----------



## The Gopher

i think anything that pushes a band to it's maximum performace will have a shorter life. Flatbands are better performarers than tubes and also have a shorter life, perforated flatbands have better performance than non-perforated and also have a shorter life. I also think it was brilliant! Same thing with bow building too (all wood bows). An all wood flight bow is capable of sending an arrow several hundred yards, but a gaurantee you that it won't last as long as a well built (maybe overbuilt) stable hunting bow.


----------



## Charles

Thanks for the kind comments, everyone. It was a fun and interesting experiment to try. Gopher, I am afraid you are right ... when we push for maximum speed, we seem to significantly shorten the life of the band or tube, no matter how we go about it.

Well, I have a few more things to try, but I think I am going to abandon the perforation approach to increasing speed. If anyone else wants to play with it, then I yield the floor.

Cheers ....... Charles


----------



## bj000

tapered bands with holes would be something. if i ever have enough theraband to throw away,. then i will try it out..i gotta look into these elastics everyone uses.


----------



## Jacktrevally

Intelligent idea Charles.

This got me thinking all day how I could taper a pre-cut straight strip of elastic without cutting them to a taper. I gather that you are using flat elastic bands loops like the Alliance which have a staight uniform cut when the loop are cut open?

Don't know if this might work but, let me try to get a schematic.


----------



## Jacktrevally

http://postimage.org/image/1ppm82zac/

The idea behind this is to get a sleeker profile near the pouch, like the tapered bands larger at the tip and slimmer at the pouch.

If you have a straight pre-cut you can try the above. I haven't tried it because I don't have any flats on hands and I'm still thinking how to get a chrony through local custom.

Idea behind is to fold the bands at the pouch amd hold it in place with a piece of 2040 tubing! The blue elastic I used in the schematic is just to show how the tubing can hold the fold.

According to me this will work, but to how much % speed gain? I don't know but the bandset can be easily done and you get a folded (double thickness) at the pouch which will give you a bit more bandlife.

Just my views.

Cheers,

Kevin.


----------



## Charles

Jacktrevally said:


> Intelligent idea Charles.
> 
> This got me thinking all day how I could taper a pre-cut straight strip of elastic without cutting them to a taper. I gather that you are using flat elastic bands loops like the Alliance which have a staight uniform cut when the loop are cut open?
> 
> Don't know if this might work but, let me try to get a schematic.


Yep ... exactly right. I was using Alliance 105s, which when cut yield a strip about 10 inches long. The same bands, unperforated, have lasted over 400 shots so far, and seem to be just fine.

Cheers .... Charles


----------



## Charles

Jacktrevally said:


> http://postimage.org/image/1ppm82zac/
> 
> The idea behind this os to get a sleeker profile near the pouch, like the tapered bands larger at the tip and slimmer at the pouch.
> 
> If you have a straight precut you can try the above. I haven't tried it because I don't have any flats on hands ansd I'm still thinking how to get a chrony through local custom.
> 
> Idea behind is to fold the bands at the pouch amd hold it in place with a piece of 2040 tubing! The blue elastic I used is just to show jow the tubing can hold the fold.
> 
> According to me this will work, but to how much % speed gain? I don't know but it is easily done and you get a folded (double thickness) at the pouch which will give you a bit more bandlife.
> 
> Just my view.
> 
> Cheers,
> 
> Kevin.


Certainly this idea is worth a try.

But I think the main increase in speed from tapering is due to the reduction in mass toward the pouch. The pouch end has to be accelerated over the greatest distance. So if we reduce the mass of the part that has to be accelerated the most, we should increase the speed. Of course air resistance plays some role, but in this situation, I believe it is minimal compared to the role of mass.

There is another problem with your approach. I have been using short sections cut from tube for pouch ties. In my experience, the flat band opens within 1/8 to 1/4 of an inch beyond the tubing ring. So placing a single tube ring along the band will not keep it folded. To keep the band folded, one would have to place a large number of such rings along the band, thereby adding significantly to the mass where one least wants it.

Now, all of the above is just idle speculation on my part ... I do not mean to be critical of your suggestion, nor of you for raising it ... I am just sort of brainstorming here. Experimentation is the only real test.

Cheers ..... Charles


----------



## Jacktrevally

You are right.

I thought a tubing holding it at the pouch and a couple of inches up would be sufficient to keep it folded.

Now you raised the post of the mass issue, this got me thinking again. I thought the decrease in air resistance would havean effect as the tapered part near the pouch is the part of the band that travel most on the release.


----------



## dgui

Charles, you are a deep thinker and this seems to be a Light Bulb moment.


----------



## Ry-shot

good idea !


----------



## Guest

Really quite brilliant. Way to think out of the box.


----------



## quarterinmynose

Fascinating, truly I a great thought, success or not.


----------



## jazz

Hi Charles,

I like this idea very much, true creativity at work, thank you.

cheers,

jazz


----------



## Charles

Thanks again for the kind comments, everyone.

I was pleased that this idea helped me to get over 30 fpe using Alliance 107s in the Power Rangers competition. But band life was very short when trying to get that amount of power out of perforated bands.

I have been thinking that the more severe the taper, the shorter the band life. The less severe the taper, the longer the band life. Many folks use slight tapers on their flat bands to get a little extra speed, without too much of a compromise on band life.

When doing perforations, smaller holes correspond to less severe tapers. So, one thing to try is using smaller holes in the bands to see if one can get some reasonable increase in speed without such a huge sacrifice in band life.

There is always something else to try ....

Cheers ...... Charles


----------

