Roller spearguns

  • I challenge anyone to produce video evidence that between two wood spearguns with identical stocks, shafts and bands, the roller speargun has more power ie. more penetration at the same range than the conventional version. By identical band power I mean for example: conventional 2 x 16mm and roller "1" x 16mm.


    My premise is that personal anecdotes are just that, but physics don't lie. If you take a roller speargun powered as described above and turn it on its side, you'll see the same exact configuration as the conventional speargun, with one band stacked on top of the other. More so the bottom anchoring point doesn't always reach quite as far back as the last tab on the shaft, so band stretch is actually less. The pulley being the only differentiating factor, are divers supposed to believe that it somehow magically amplifies the stored energy of the bands?!


    Nor do I believe that the roller's band powering the shaft longer is a factor. The dispersion of the band's energy over the top and bottom of the speargun may or may not result in less recoil. But that's nothing that a conventional speargun with the right mass can't do. Even if it were true, it's by far offset by the tedious loading procedure. But I digress, this is about one claim "more power" so show me the money.

  • I have nothing to contribute to this thread as I have not shot a roller gun as of yet. A friend of mine loves his 85cm roller though!
    I can also visualize a roller gun being a conventional gun put on to its side. Thinner bands too!


    What I can say is that in terms of recoil, an ergonomic handle and bands parallel to the shaft help absorb recoil much better than non-parallel bands. The spearo's hand absorbs the recoil much better this way.


    I'm sure there's some solid science backing up roller guns, so I'm gonna wait for some other people to chime in on the subject.

  • I would like to see the challenge.


    for example 2 roballen of equal size, band and shaft but one roller kit.


    Lucky hunter myths :thumbsup2:

    Un Hombre tiene que creer en algo.......
    Creo que me iré de pesca!!!

  • Dan has thrown the gauntlet or more like the old days (yes I was there) slap the face with a glove and throw it down :laughing:


    I have never used a Roller Gun BUT I spent a day spearfishing with a really good Italian Spearo who essentially did it for a living. He guided people (not me he was on a free day) and today is living on a yacht in the Red Sea "helping/guiding" some ultra rich guy. I mention all of this to indicate - this guy was GOOD and I was impressed at his fishing abilitities.


    He had two Roller Guns and spent some time before and after the day trip showing me his two guns and explaining to me HIS conversion from regular banded gun to Roller Banded Gun. He said, direct quote, he said "I get the SAME power with a shorter more manurable gun as I do with a regular banded gun that is much longer. I love how I can hunt caves & holes with shorter gun but still have the power and range for Blue Water Fish."


    Not MY experience but this seems to be what makes the Roller attractive to more and more folks. I have no intention of switching - I like KISS.

    The post was edited 1 time, last by Oscar ().

  • In all due respect for you Dan and the experience you represent I say the following .You want some one to show you the money...why don't you just try it yourself? That's what I did. The issue for me is not that the power of one is equal to the power of the other. For me and where I hunt mostly, I need a shorter gun without the significant sacrifice of power and effective range of my standard length gun. And I have found the answer in cutting down my barrel and converting to a roller muzzle. I now can maneuver in holes and caves but not miss out on the open water fish. Period. Instead of cerebrally debating the theories of shooting fish, I decided to try it myself and actually get some fish, and I am glad I did. For me it's now knowledge of what works for my circumstance and not merely a theory to be debated over and over and over and over.......again. Just try it. You have the means. Then post YOUR results and experience with it. Perhaps in South Florida's open water your long pipe guns will be a better tool than a shorter roller gun. The point is, unless you actually try it and put the gun through your own personal trial, it will just remain an "idea" and "theory" that you and others are waiting to be convinced by someone else's typed words or posted video.


    I respect traditional thought and the experience of spearos world wide. Regardless of how smart scholars may appear to be, there is no substitute for knowledge gained through the actual trial of personal experience. At that point the knowledge is yours and not merely someone else's opinion. So instead of waiting to be shown the money, go try a roller muzzle, put it through your own set of tests based on what you need, then post the results. No one could argue with what you had to say then unless they they haven't done the same.


    I was headed out the door to shoot fish when I saw this thread. Now I'm definitely going to shoot some fish.

    HUI KOA KAI O HAMAKUA
    MAHALO KE AKUA
    E MALAMA I KE KAI

  • In all due respect for you Fan and the experience you represent I say the following .You want some one to show you the money...why don't you just try it yourself? That's what I did. The issue for me is not that the power of one is equal to the power of the other. For me and where I hunt mostly, I need a shorter gun without the significant sacrifice of power and effective range of my standard length gun. And I have found the answer in cutting down my barrel and converting to a roller muzzle. I now can maneuver in holes and caves but not miss out on the open water fish. Period. Instead of cerebrally debating the theories of shooting fish, I decided to try it myself and actually get some fish, and I am glad I did. For me it's now knowledge of what works for my circumstance and not merely a theory to be debated over and over and over and over.......again. Just try it. You have the means. Then post YOUR results and experience with it. Perhaps in South Florida's open water your long pipe guns will be a better tool than a shorter roller gun. The point is, unless you actually try it and put the gun through your own personal trial, it will just remain an "idea" and "theory" that you and others are waiting to be convinced by someone else's typed words or posted video.


    I respect traditional thought and the experience of spearos world wide. Regardless of how smart scholars may appear to be, there is no substitute for knowledge gained through the actual trial of personal experience. At that point the knowledge is yours and not merely someone else's opinion. So instead of waiting to be shown the money, go try a roller muzzle, put it through your own set of tests based on what you need, then post the results. No one could argue with what you had to say then unless they they haven't done the same.


    I was headed out the door to shoot fish when I saw this thread. Now I'm definitely going to shoot some fish.



    He did and he hated it, that's where all this is coming from lol

    Scupper Pro Gives You Wings!

  • Makoa, I'm surprised you were under the impression that I never used a roller speargun. I gave you some good advice on building one (based on my experience) in another thread.


    Please note I didn't post negative comments about roller spearguns in other's threads because I didn't want to be rude and/or derail them. Even though I felt just as compelled to do so as roller fans are to post in my thread. This thread is just my conclusions about the roller speargun, focusing on the facts not personal interpretation, which I think may be of interest to others.

  • Yes, you gave me some great advice. Your technical mind is why I respect your opinion. I didn't know however that you had experimented with roller guns yourself. My bad. I have tried to express MY findings based on what I needed the roller gun to accomplish and I am well pleased with what I've discovered. The facts for me become another's opinion which is why I suggest to those that are interested to just try it out. It may or may not be what they are looking for in the conversion. There is no ONE perfect gun that does it all but I guess we are always trying to create one.


    I hate the typed words because you never know the tone of the writer. Please know that the tone of this and all my posts are meant to be respectful and never "in your face" disagreeable. "Live Aloha!" Thanks for the clarification.


    Makoa

    HUI KOA KAI O HAMAKUA
    MAHALO KE AKUA
    E MALAMA I KE KAI

  • Awww shit. I guess I have to cancel my roller gun order. It's for the better. My wife would kill me if I got another gun.
    Great info here. Thanks.


    Actually a Roller Gun might be good for hunting Pargos and Groupers holed up in your Reefs and still powerful enough for open water/long shots. You never know unless you try it Hank. Your wife will never know, do what I do, be home when it arrives and hide it with all the other guns. Besides she is busy making new Hanks and Miss Hanks to notice the gun pile got a little larger :laughing:


    Regardless - great to read various opinions done in a respectful manner. :)

  • From my understanding of the physics, all of the advantages of a roller gun come from where the top band stops applying force.


    On a classic configuration the bands no longer produce force once they have reached their relaxed size. On a gun with 100 cm from band hole to mech this is somewhere between 20 and 30 cm from the band holes. From this point forward the spear is no longer accelerating.


    On a roller gun the band pulls all the way to the tip of the gun. This provides two advantages. First, if comparable bands are used in both guns then the shaft from the roller gun will leave the speargun at a higher velocity. Assuming the mass of the spears is the same this will give it more kinetic energy/momentum and will lead to better penetration (also assuming the tips of the spears are identical).


    The second advantage of the longer band stretch is the recoil. One way to look at recoil is wight the impulse momentum theorem. F = (Change in Momentum/Change in time). Because the spear is accelerated over a larger period of time the felt force is smaller. This is why guns rigged with 3/4" bands are described as "punchy" or "snappy" The band produces a large amount of force in a very short time. Guns with short thinner bands are often described as having a much smoother recoil.


    Personally I think rollers have their purpose but are not necessarily for everything/everyone. They make sense for blue water where you aren't taking a lot of shots and reloading a bunch and the shorter length is helpful for maneuverability. They are also good for holes as mentioned. Perhaps their best use is in really dirty water shooting big fish. When you can't see more than a few feet having a 120 just isn't practical but you still need the power to penetrate a large fish like a striped bass. For SFL with clear water and constantly hoping in and out of boats I don't want to deal with the reloading process so I don't use them.


    Just my .02

  • I agree with wishihadgills, that is the idea behind a roller. I think comparing two spearguns,one roller and one single band is a better comparison. If they are of the same length, same spear, band thickness, etc the roller should theoretically be better, if you shorten the roller by the relaxed normal speargun's band's length then they should be equal. Comparing a multi band speargun of the same length with the same band thickness is not a good/fair comparison.


    I have a roller, two multi bands (one with 2 and one with 3) and 3 single band guns, unfortunately none could be correctly compared to each other. I can say though that the roller has less recoil, the roller and the multi band guns are equally a pain to load when in a hurry. They can both be fully loaded half loaded depending on the distance of the fish. Also, my multi band guns have thinner bands then the euro (single band) and than my roller (if not they would be horrible to load). I believe each type has its pros and cons, neither can be declared better. I enjoy them all, in different situations.


    It's like comparing a Hummer and a Lamborghini, both powerful cars just not in the same way. On a racetrack I would use the Lambo but on the sand the Hummer, the other way around would suck :)

  • Xan, yes the roller's band accelerates the shaft right up to the muzzle. But the force with which it does so is the force of two single bands over the distance equal to the stock/barrel length. The two band conventional speargun accelerates the shaft over 2/3 that distance, but it does so with the force of 4 single bands. Combined with the fact that the bottom anchoring point on the roller doesn't utilize the full stock length for band stretch, will result in a conventional speargun actually having more power. Some of that power will be dissipated through recoil if the gun doesn't have the right mass, shaft/bands configuration, and other details like elevated bands and handle. But if these details are addressed correctly the roller over under band contraction should pose no significant advantage in terms of recoil over the conventional setup.


    For grossetti and others who may be having difficulty visualizing why a "single" band roller is the same as a two band conventional speargun, I made this animation highlighting the bands with a red line. Clearer than this I can't make it. There still has been no proof of the claim that a roller has more power than an identical size conventional speargun. Only anecdotal observations echoing one another with a single recurring theme; no relation whatsoever to physics.


  • Xan,


    I disagree on the roller sending the shaft with higher velocity to the point that gun builders like koah who make rollers now are adding an additional standard circular band to increase acceleration because on rollers he shaft is actually leaving the gun slower..

    Relax & Go Spearfishing

  • Chase: I wasn't analyzing a particular brand of roller gun. I was simply explaining from a physics point of view why a roller gun "can" produce more power than a conventional gun of the same length.


    When it comes down to it there is only one way to produce higher velocity more force for longer time. If it does not move the shaft faster then it won't have more power and nobody would be claiming that. There is no magic.


    There are two tests that can be done pretty easily. One is check the velocities with a chronograph to see if they move the shaft faster. The next is hook a force gauge on the bands at full stretch to figure out how much force they produce. A fishing scale will be accurate enough for this to work.

  • I respect your opinion Xan. I know you have credentials to back up your theories. I was simply saying that most wood gun builders that I talked to particularly @ the expo said the shaft leaves the gun rather slowly, so they put on an extra circular band to help accelerate the shaft from the gun to increase velocity. A standard roller gun with one band as Dan said is "waiting for the shaft to leave the gun"...

    Relax & Go Spearfishing

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