Super Bands

[gitano]

I am looking for the best bands 16-20mm range. I have heard that big static pull forces don't always mean higher shaft speeds. This makes sense because I have put tons of weight on winch cables and when they snap they barely move themselves(just enough to be scary). The elasticity is the most important part. If a rubber is slow to recoil back to its original resting static position it will not accelerate the shaft to greater speeds no matter what size.

The question remains, who makes the greatest accelerating compounds of rubber? Is there any real scientific data for elastic recoil capabilaties?

 

[Hawkeye31]

Rubber compounds

Ive never used anything but the standard issue store bought rubbers, but others seem to have done some serious testing. Look at the freediver.net website under the FAQ sction if this link dont work. Ive heard good things about Mean Green.
http://www.freediver.net/freedivelist/faqstuff/faq_bands.html

Later
Adam

 

[Iyadiver]

I think short of a radar gun or ballistic chronograph, there is no way to tell 100% how "good" a rubber is compared to the others.

Cheapest test method I think will be a ballistic putty penetration test or any material with consistent density and hardness, unlike wood. I used to test my air gun pellet using a telephone book when I do not yet own a chronograph, it does tell something but make sure the angle of penetration is similiar between shots.
Maybe try to use a medium to low density polyurethane (spelling ) foam as test material ? Higher rubber rebound speed means more shaft speed and thus more penetration.

 

[gitano]

thanks

Thanks for the input.

Iya, I used to do the same thing with telephone books and pellet guns. I think that target patterns and ballistics gels/putties will be sales pitches in the future for spear guns. There are already competitions in Italy for immeresed target shooting and biathlon. You can find it in www.apneamagazine.com under the "tiro sub" page. It is very interesting stuff and you see the likeness to its land based brethen. (sorry everything is in Italian but I can send some translation if you like)

Hawkeye, I have read this article previously and find it very interesting. The problem is that one thing was not accounted for, the friction and hydrodynamics of water. These tests need to be performed in water because a small band can accelerate more quickly with reduced friction. The variable between high friction and low friction is greater for small bands than it is for larger bands? I was also very disapointed that the names of the products were not released. They should have at least discovered the names of the rubber manufacturer and left the euro end assembler out of print.(dunlop, michelin, goodyear, dupont, etc.. not beauchat, cressi, omer, sporasub,etc...)

Thanks to you both.

 

[fuzz]

Here's some interesting literature for you Gitano.

 

[w3ac]

different rubber for different guns

Hey guys,
Thought I would chime in as usual. Interesting test results Fuzz. I currently use 3 Mean Green (I don't know what batch) on my 55" Wong. Overkill? Maybe, but when you gotta knock some Ulua senseless or those damn Mu and Uku don't want to approach, the extra power is welcome. You can always uncock one or two bands for shooting in holes. One thing I noticed about the mean green is that it is a very stiff, hard rubber. It is not soft like amber, nor is it stretchy like Kent black rubber. More similar to white rubber but a lot stiffer. The draw takes some getting used to and I have had to lengthen my bands from 19, 20, and 21 inches in black to 24, 25, 26 Mean Green. The stuff is explosive and once the trigger is pulled, the shaft is gone. If you want speed, I think the mean green is the way to go. For penetration I would stick with a high mod. black band. These seem to have better penetration to me.

For my 66" blue water gun, I stick with 5, 5/8 black. I tried extra long mean green and nearly soiled my wetsuit trying to load them. The black works fine as far as range and penetration go. Speed is not really a problem because 5 bands are being used. Just my own experiences.

Brad :martial

 

[gitano]

ballistics

Brad, I have been reading a book about ballistics and I think that I have discovered the explanation for what you had described, penetration vs speed. If you use a quick elastic that is difficult to load and thus compensated by using longer rubbers, the effective duration of power is shortened. This would explain a high speed release with less penetration. What is the absolute biggest dia. for "mean green". Don't worry about loading(I trained a gorillia to swim and he loads my guns for me), I have a system that seems to be working just fine, even for a cripple like me.

Fuzz, Thanks that data looks promising to say the least.

I would give karma to you both but it seems that I have to spread it around first

Gabriel

 

[Iyadiver]

you know what, until today I can not comprehend that Mori rubber test in full.....:head . Anyone can help out ??

Gitano, I agree that unless the test is conducted in water, result can't be very accurate. I too been wondering if 5 x 9/16 is better than 4 x 5/8 set up.