15 replies to this topic

[ZDP-189]

shot in the foot showed that stationary-store rubber bands could be chained to make slingshot bandsets. I found this exciting because it would greatly simplify buying bands and offered a potential improvement over the flatbands I was using. I thought I'd share the experience with you here.

With flatband sets that I was familiar with as a reference, I tried to create band chain bandsets similar in terms of draw length and draw weight.

Test Bands:

• Small Chain 1" bands; chain and pouch mass 1oz; construction formula 7,7,7,7,7,7,7,8,8,9,9; 4" long drawn to 2.5' at 12 lbs
• Heavy Chain 1" bands; chain and pouch mass 1.5oz; construction formula 11,11,11,11,11,13,13,13,14,14,14,14; 8" long drawn to 2' at 21lbs
• Loose Chain 2.75" bands; chain and pouch mass 1.25oz; construction formula 7,7,7,8,8,9,9; 6" long drawn to 2' at 15lbs

Reference Bands:

• Thera-band Silver; band and pouch mass 0.75oz; construction formula 2.5" tapered to 2"; 8" long drawn to 2' at 15lbs
• Thera-band Gold; band and pouch mass 1.5 oz; construction formula double strips of 30mm wide bands (Hunter bands); 6.5" long drawn to 2' at 20lbs

Ease of Construction:
Creating the bandsets took more time and effort than cutting exercise bands, particularly the small 1" rubber bands.

Testing:
No quantitative testing was performed. Instead, I shot at a target at approximately 15' with two types of ammunition at different ends of the weight scale that I typically use.

Ammunition

• Heavyweight - 15g 0.5oz lead sinker
• Lightweight - 6mm copper BB

I shot each bandset on two frames; my shop catty and The Shootist.

Results:
I found the stationary rubber bandsets I had created to be highly inaccurate and slower compared than flatbands. There seemed no point in continuing with qualitative testing in a bench set-up.

Projectile Velocity:
Ignoring different but similar pouches and elastic material, I found the stationary rubber bandsets are similar to but at least as heavy as flatbands. I think this is because elastic used to hold the bands together is not used to pull the shot. Secondly, stationary rubber bands are almost twice as thick as even Thera-band gold. I believe that cross-sectional perimeter/area is a factor in determining the speed of a bandset. Although stationary rubber bands' surface area is increased by their increased number, it does not make up for their greater thickness.

Cross-sectional perimeter/area:

• Stationary rubber band: 2.7x
• Thera-band Gold: 2.8x

Accuracy:
Accuracy of stationary rubber bands suffered greatly. Groupings were substantially larger and there were several fliers that deviated by 20 deg or more. The shorter bands were worse in this regards. I believe this was because the contracted bands were stiff and prevented free and unhindered release of the projectile.

Heavy Chain


Small Chain


Durability:
I found the band life of stationary rubber bands to be shorter. This is possibly due to the use of natural latex, variation in thickness and their strand structure, whereas flatbands have fewer places where a tear may be initiated.

Safety:
Wear would have been apparent on inspection. Although the bands did not fail during use, the staggering lack of accuracy was worrisome. In addition, I managed to hit my hand square on the web with a half ounce sinker at full draw on the 2 3/4" bandset. This was a first for me. Low forks were likely a factor. In one instance the bands came off the fork despite being securely attached. There was no injury involved.

Conclusion:
I concluded that the stationary rubber bandsets that I had created offered me no advantage over flatbands in my style of shooting and I have no plans to use them in the future.

Please note that I don't doubt shot in the foot's own findings and positive experience with band chains. What suits one person may not suit another. I make no claim that this testing was done in a scientifically rigorous manner nor would the same performance necessarily apply to better designed bandsets with different bands. If members would like to try these bandsets, let me know and I will send them to you.

Further Research:
I have seen thin elastic line used in beadmaking. This would seem to solve many of the technical issues identified in these experiments and warrants testing. Shock cord elastic may also be suitable, depending on materials, quality, thickness and bandset construction.

[ZDP-189]

I even managed to smack myself with a half ounce sinker at full draw on the loose bands.



The two central hits were from today. The other wounds currently healing are unconnected.

[shot in the foot]

when i do mine i start at 6 at the pouch and to 9 at the fork, my bands seem a bit bigger than the ones you used, i try it with smaller bands before but i was off target, i seem to hit the target with the set up i do, but like you say it works for some but not others, the bands i use are pure latex, for target shooting i start at 4 at the pouch and 7 at the fork, jeff

[ZDP-189]

The longer and larger the band the more it would be like a flat band. Maybe larger bands would be better.

[Brooklyn00003]

ZDP-189, on 27 March 2010 - 11:53 AM, said:

The longer and larger the band the more it would be like a flat band. Maybe larger bands would be better.

Yes, I believe too that your bands are just tight and close to each other ,they sure need some free moving space in order to perform better.I have tried these with postal bands but they broke allways then I stopped trying. Great test you have performed we got useful information out of it Thank you and keep it up .

:Jaydee

[SnodyKnives]

shot in the foot, on 27 March 2010 - 11:40 AM, said:

when i do mine i start at 6 at the pouch and to 9 at the fork, my bands seem a bit bigger than the ones you used, i try it with smaller bands before but i was off target, i seem to hit the target with the set up i do, but like you say it works for some but not others, the bands i use are pure latex, for target shooting i start at 4 at the pouch and 7 at the fork, jeff

Thats Slick....

[shot in the foot]

SnodyKnives, on 28 March 2010 - 10:38 AM, said:

shot in the foot, on 27 March 2010 - 11:40 AM, said:

when i do mine i start at 6 at the pouch and to 9 at the fork, my bands seem a bit bigger than the ones you used, i try it with smaller bands before but i was off target, i seem to hit the target with the set up i do, but like you say it works for some but not others, the bands i use are pure latex, for target shooting i start at 4 at the pouch and 7 at the fork, jeff

Thats Slick....

Cheers Ive just see your videos, there great, love the music as well, jeff

[ZDP-189]

This is about the worst it got. I think the photo was taken on April 30. It's almost back to normal now, but the two wound sites are still visable and I've a strange lump in the web of my thumb.

[Redgrange7]

Ewww. That is absolutely nasty.

[Redgrange7]

I just got this thought after my last post. Wouldn't you want to stop after getting hit the first or second time as opposed to waiting for your hand to develop huge, red bumps? How did you manage to hit yourself that many times, anyway?

[ZDP-189]

There was only one hit. I got hit by an oval sinker on the 27th which left two holes as it tumbled and the bruises developed getting darker then lighter then spreading until they looked their worst on the 30th. The other wounds on my hands are most recently from opening a beer bottle on a wall, and several legacy scars from working in the shop and basically a lifelong childhood. If Peter Pan had been for real he'd have been a mess of scars, replaced joints and pinned bones.

[smitty]

Ouch !!!

[ZDP-189]

Another flop:



Ladies' headbands (some 250 of them). Despite great elongation of over 6.5x and excellent snap back, they aren't strong enough and constantly beak, losing a few on every draw. The sad part is that they are made from tubes and if I had one of those uncut tubes I am sure it would work well.

[Brooklyn00003]

At least that slingshots looks great.Is that the one made from jeans?Just a funny thought what if you would use ladies thongs as the last sheet?That would be somethink isn't it?

[ZDP-189]

Yes, it's denim. I did a tutorial on how to make it. Here's a link to discussion of the material and the slingshot and more pics.