New Hawaiian Sling design

[ruppst]

Hi
I would like your comment on this new Hawaiian Sling design. I designed and produce it in limited numbers at this time. I feel it is a revolutionary concept and the best triggerless sling available. You can view more at www.hawaiiansling.net

 

[cdavis]

new sling

Interesting design, I'd like to try it. My past experiance with pistol grip slings was poor,. With all the power on top of the wrist, I could not keep a straight aim when releasing the spear.
Does this design work in spreading out the force evenly above and below the wrist? Compared to a normal sling, pistol grips, give up a little length of rubber,the difference between the wrist extended and upright, plus the attachment in a normal sling is in front of the wrist. Even after balancing off band size and length and cutting the rubber to my arm length, I always thought this was resulted in slightly less power. This design seems to get around that problem. How well does it work?

 

[ruppst]

You have stated the problem precisely that this sling solves. This design is so well balanced to the anatomy that when fully powered you can open the hand holding the handle. The sling nestels into palm of the hand and requires no counter forces to control it. The wrist is in such a locked position that the force is tranfered evenly through It. The elbow and shoulder are in a correct anitomical position for handleing this force as well. Truely this sling is balanced to human anatomy not only of the wrist but to the elbow and shoulder accross the pecks to the large muscles of the powering arm. You can also add heavier strength bands, this balance remains. The only limit to the power one can develop lays with the muscle strength of the larger muscle groups involved and not on any moment on a weaker jiont. Moving the bands foreward also allows for band lenghth and the over under design allows "pretensioning" of the bands so nothing in the anatomy of the "pull" is lost to floppy bands. Power is added at the first inch of pull to your maxium reach. The release is with out kick and shoots quite straight. the design is a natural in aiming as you site down the shaft as if you were using archery. No other sling has gone this far that I know of.
Thank you for seeing what I have worked to accomplish.

 

[fuzz]

It's a very nice intuitive design - good job!

 

[ruppst]

Thanks
I spearfish the Bahamas often, no triggered spear guns are allowed by Bahamian Law. Thats why I spent the time to come up with a better sling.

 

[j.grady]

I was wondering how you pull back the shaft, the space where the shaft sits in the holder looks really narrow, not enough to get your hand around if you use a heavier band, also, how durable is the handle, does it break easily?

 

[ruppst]

Loading Sequence

There is a unique loading sequence. ( If your R. Handed ). First, with the shaft in the sling, you hold the muzzle end and shaft in your L. hand, Then pull about 10" of power into the sling and hold it there with the L. hand. the Right hand then grabs a fist full of the bands and shaft. The L. hand moves to the handle. You then pull full power into the sling. If desired. can increase the power you develop if you grab further up the shaft during the loading sequence. It sounds complex in writing but soon becomes second nature in practice.
I have taken a 1" thick block of this material about 6" in dia. slammed it to concrete as hard as I could. No fracture of the material was noted. The manufacturer of this plastic states an ultimate tensile strength of 3,000 psi. It is very strong!

 

[PILOT]

how are the hydrodynamics on deep dives? it seems to be a bit bulky in the photo, is it possible to hold the shaft loaded (not pulled back) in one hand whilw ascending/descending or does the wing design tend to "stear" you? Also, could you please post some more picks of different angles.

 

[ruppst]

he Sling is easy to swim with. Slide the handle up the shaft near the barb and keep it close to your side.

 

[ruppst]

Note the penitration.

 

[Shadowkiller]

So you shoot it like a bow?

 

[ruppst]

Yes! It has characteristcs like a bow. First the wrist is in a position to support the extra power this sling develops. Note that the hand on the handle is open. It is balanced to the hand and requires no counter force to aim it straight. When released the shaft does not kick but flys straight. Holding it like a bow allows sighting down the shaft for more accuate aiming. It is unique design for a triggerless speargun. It works!

 

[unirdna]

And you even got Kid Rock to demonstrate rofl.

.

I've been following this post since it started, and must say that the design looks great. At a glance, it looks very simple, but after a little more observation, it's clear that a lot of thought went into this.

One question: Was the angle (on the plastic) for the lower band deliberately made [sharp enough] to prevent the whole band from stretching (possibly to make the bottom 'stretch-length' more equal to the top)? I ask because I noticed that the band is still fat (unstretched) near the muzzle (Area C on the photo). If it's not deliberate, and thus more beneficial for the entire band to stretch, could a small amount of lubricant (silicon spray for example) be applied to the plastic and/or band to assure that the band would stretch 'around the corner' - so to speak?

?

Ted

 

[cdavis]

new sling

How large is the hole the shaft fits through? I use a sling with an enlarged hole to minimize transfering vibration from the sling to the shaft. Keeping your fingers open would help cosiderably in reducing the tendency to bobble the sling on release, but I would be concerned if the hole is very small. What is your experiance??

The bands pictured look pretty light. For shooting fish, I use fairly strong bands, capable of shooting through the backbone and body on a 20-30 pound fish . Some divers use much stronger bands. Can you load up this sling with strong enough bands to be equivalent??

 

[ruppst]

I like the bore tight as possible without binding the shaft. Too much slop in the bore will effect accuracy. I make the sling with two bore options. The larger bore works well with the 5/16" shaft and the 7.5 mm shaft. It will work with 7mm shafts but becomes a little sloppy. The smaller bore works well with a 7mm shaft and a 1/4" shaft. Seems most order the larger bore. I hunt with the larger bore most often as I target larger pray. But if I am in an area that is mostly smaller fish or lobster I use the smaller bore. The Larger shafts kind of devistate the smaller pray.
Band stength is a matter of personal ability. This gun gives you option to use a band upto your personal muscle strenth if desired. The 20lb grouper pictured earlier was hit in the gill plate the shaft penitrated above the pallet through the skull out the other gill plate about 6". If you used other slings you know that is exceptional. The heavy power band was used to achieve this.

 

[ruppst]

Unirda
Thanks for your reply. I am happy your interest was held. Keep it simple is a good design goal.
Very good observation. I made several prototypes before settling on this design. Balance with as much power as possible was the goal. Band length and agle of pull in relation to band keepers changed several times to achieve this. The silicone is a good thought. But in this photo Fabio is out of the water, Water will lubricate the band to some extent. I should have a pic under water and observ the friction that you are observing. Limiting band contact in the keeper will avail to that end as well. But at this time this sling is well balanced with no observable kick when the shaft is released developing much more power than other slings I've used.
Thanks for your reply
Ray

 

[ruppst]

Reply to unirda

Unirda
Thanks for your reply. I am happy your interest was held. Keep it simple is a good design goal.
Very good observation. I made several prototypes before settling on this design. Balance with as much power as possible was the goal. Band length and agle of pull in relation to band keepers changed several times to achieve this. The silicone is a good thought. But in this photo Fabio is out of the water, Water will lubricate the band to some extent. I should have a pic under water and observ the friction that you are observing. Limiting band contact in the keeper will avail to that end as well. But at this time this sling is well balanced with no observable kick when the shaft is released developing much more power than other slings I've used.
Thanks for your reply
Ray

 

[ruppst]

The home site is http://www.hawaiiansling.net

 

[kellya]

Looks good do you ship to canada? price of shipping??

 

[ruppst]

Yes I ship internationally. I use US priority Mail, 3 to 4 days delivery usually $10 to $20 shipping depending on your order. I have shipped to Bahamas, Puerto Rico and all over the US. I had one guy e-mail me from American Samoa but it was in the $200.00 range. I guess he decided to wait. Canada should be no problem.
Thanks for your interests
Ray