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new OMER pneumatic!!!

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
popgun pete said:
Some interesting comments here from an "Airbalete" user. http://www.extremespearfishing.com.au/modules.php?name=Forums&file=viewtopic&t=3088
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BTW, the diver Jomas who wrote about his experience with the AIrbalete, which I think was a very fair asessment for a diver not used to using pneumatics, should be notified that the slide ring (microfusion) was changed. They were tapered a bit at the beginning causing the slide ring to get stuck on the tail and this phenomenon happened to me as well, very frustrating. He should email infotech@omersub.it and they will be happy to mail him a replacement from Italy or through his distributor.

About the aim of the gun, a diver who hasn't used a pneumatic gun in ages will take time to get used to the aiming, best done in a swimming pool first if you're a band gun guy. It's just a characteristic of air guns. You have to aim the gun by covering the fish with the gun rather than aiming with the tip of the spear (triangulation issue). As I did he missed several intial shots at fish.
 
spaghetti said:
So Mark what's your take on the One reel compared to other Omer reels? Is it durable? Did you receive any warranty claims for breakage or malfunctions so far?
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I have not but we don't have a whole lot of them out there aside from AIRbalete and ONE speargun owners. The reel although manufactured by Omer has a new brand name and if people, like w/any new product, don't recognize a brand they are skeptical to try it. I think it is considerably beefier than the OMER equivalent Match reels and the line capacity is better. I have not seen or heard of a single issue with it yet here (that doesn't mean it's perfect).
The main feature I like about the ONE's is the size and the drag feature. Many divers underestimate the benefit of quickly releasing the drag during ascent and this is a main feature of the ONE reel. The drag knob turns in the same direction as the spool turns. So setting the drag is counter intuitive at first. But because it does that it means that when the fish runs off and you head to the surface the only requirement of the diver is to hold the reel firmly and blocking the drag knob automatically releases the drag, a more natural reaction than fiddling with it all the way to the surface. I can imagine some people buy this reel and it's not obvious right away and it probably annoys them. The 80 version is ideal for fishing here in the Oceans, a Match 50 sometimes gets spooled in a few seconds by comparison.
 
I would not take the velocities measured in the Luciano Garibbo tests to be definitive as the test method used influences the result. He says so himself on the "analysis of method" page. Comparisons can only be made for guns tested in exactly the same way, here the spears were hauling a line that was marked to produce a frequency signal as it travelled through some type of detector that sent a signal to a computer. That is why time measurements were taken to six figures, one part in a million! (Niko Brummer used a similar method when he was measuring band gun instantaneous spear velocities some years ago.) It is instructive to examine the variation between repeat shots for each gun!

"il trascinamento di questo monofilo riduce le prestazioni di ogni configurazione e la sua influenza è in diretta relazione con la velocità e il peso dell’asta, in pratica durante il tragitto l’asta subisce un rallentamento inversamente proporzionale all’energia cinetica nel momento."
which roughly translates as "the dragging of this monothread reduces the performances of every configuration and its influence is directed in relation with the speed and the weight of the spear, practically during the way the spear endures a slowing down inversely proportional them to the kinetic energy in the moment."
So the marked measuring line is affecting the results due to its extra drag, but the effect is proportionately less on shafts travelling with greater momentum. I do not think that you can compare band gun speeds with pneumatic gun speeds unless you know the testing conditions were the same for both. Pneumatic guns can produce very high velocity shots, they do not give anything away to band guns. It all boils down to the level of propulsive force utilised which involves the loading effort employed and the efficiency of turning that effort into velocity of the spear. If you have plenty of power available (e.g. through incremental loading) then you can throw some efficiency away and still have a very fast shot. Pneumatic guns generally gain their performance through higher efficiency, especially vacuum barrel versions. High performance hydropneumatic guns use the brute force method, not as efficient as pneumatics, but can be manually loaded due to the nature of the hydraulic operating system which can overcome normally impossible to load against chamber pressures.
 
Reactions: Don Paul
I have both reels (match and one), since I am more used to the match reels, I am more bias toward them, most of it is because I've being using horizontal reels for many years, I am more used to the location of things like the drag.

But that being said, the new one reel with the springs holding the line worked really well, I never got a birds nest (I have got some with the match reel), also like the retractable long lever. I am still not used to the drag but there is nothing wrong with it.

Overhal it is a very high quality reel, does not lock up, also with a lots of volume, for my type of fishing the One105, I prefer using the smaller reel I think the name is One30. It made the gun ligther. I did not have any issues, but here in Alaska the season is short.

I would definitly consider using this reel on other guns.

One of the best things is the new shaft ring, I wish all my shafts were like that, Mark you should make your tecnosport shafts with that feature too ; - )
 
After trying to compare guns measuring the speed of the shaft using camcorder, what was very unreliable and inaccurate, I find this way was much better and easier:

One even could do it from the surface of the water, just submerging the gun in the water.
It is far better to measure energy than the speed.
E = (m*v^2)/2.
Well. using this method one could not measure the actual energy of the shaft but only the part of that energy. For example I measured 5,1 J to be the energy of the shaft and it was actually 9,9 J. But for comparing guns it is not a problem.
 
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I believe that fire arms & other types of riffles (air, gas) power is rated in ft-lbs.
I might be wrong but I think the original concept was how far a one lb lead ball could be moved? (or swung on a pendulum?)
Now the ft-lb rating is equated by measuring the speed of the bullet as it exits the barrel & calculating the weight of the bullet to obtain the rating.
Examples could be a target air pistol @ 6 ft lbs or a full-bore hunting riffle @700 ft lbs.
I think it is a shame that speargun manufacturers dont quote some sort of power rating as this is such an important selling factor to virtually every other type of gun known to man!
So who is going to built an underwater ballistic pendulum?
 
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Hi Pete, you are obviously very well versed in pneumatics and their inner workings, the phenomenon of back pressure you described in an earlier post had never occurred to me as a factor. I also remember Niko Brummers test you mentioned some years ago. In a nutshell his tests demonstrated that thicker shafts, while they produced slower initial speeds had more momentum and maintained their speed and energy over the long run better than thinner shafts ideal for shooting at close distances (obvious physics). This rationalized the need for big heavy multiple band guns with thick shafts for blue water hunting. The 9-11 mm shafts on some of the bigger custom guns out there initially have slower muzzle velocity but they can pound just about any animal with accuracy 30ft away (9 m). However, most divers don't have a need for these cannons.
With the pneumatics on a personal note, I've never been a fan of them in the long sizes for open water hunting compared to my band guns because regardless of the pressure and the performance the shafts are much shorter/lower mass and as a result they lose energy quickly at range.

Anyway, my attention span is limited for these technical tests and I think most people would agree the velocity testing discussion could probably be served better on a separate thread before it kills this one out of boredom but I would be curious to know your thoughts on the misconception that at depth (reachable hunting depths down to say 0-40 meters 130') pneumatics are not as efficient because of the increased pressure acting on the piston tube???
Maybe you will say this will make a stronger case for the dry kit additions like the mamba but I was always under the impression that at these depths the impact on gun performance is fairly negligent. ?

Also for the record the creator or Maori's Mamba kit sent me one to try out (7-8 yrs ago while we still had the Skorpion which I planned to install it in) and after I tried to install it as did the owner of store in Miami after me that does the pneumatic services and repairs also for Mares we both determined it was unpractical for the reasons discussed earlier and would cause excessive premature wear and tear on the guns. My own opinion after trying it is that until a major Mfg comes out with a gun designed for this system it is not something I would recommend to my customers to install in their guns.
 
strangelove said:
I have both reels (match and one), One of the best things is the new shaft ring, I wish all my shafts were like that, Mark you should make your tecnosport shafts with that feature too ; - )
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Those ring barb is way cool and it's the reason why Omer went through a ton of trouble to patent the barb system. I couldn't implement a system like that very easily on my shaft production because the tolerances are very tight and quite laborious for a small production machine shop. It would be easier to make w/the use or rubber rings etc which Omer saught specifically to avoid and they were right since rubber rots fast and is not as clean as the actual system. An interesting side note, Omer has always placed the barbs on top and no one has ever said Omer's were inaccurate. The bottom placed barb is a feature of the ONE guns, some tests they did made a strong case for placing the barb on the bottom, particularly on long range shots. The reason you only see the bottom barb used w/the Ring Barb system is the same reason Omer and the regular shafts place the barb on top, to avoid it falling in the line of site while aiming. Instead of seeing the benefit of aiming w/o the barb dangling in the way most customers here in the US think it's just an invention to help pull the fish off the shaft easier It is also that. I guess whatever works right...


A few divers and top National level divers that started using the reels have said the same thing to me, the ONE 80 reel (comes stock on ONE 100/105 AIrbalete 100/110) is a bit overkill. The ONE 50 (there is no 30 but the 50 is the size of an Omer Match 30) is enough even on the 110's. But the idea was that the reels these guns come stock on are high end guns designed for experienced divers who might find themselves over a deep drop or reef with a pelagic that would see a need for 80 meters/270' of line.
 
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Yes I can definitely see to trouble of making that ring, it is really high precision, it worked flawless. But I don't have any precision issues with the tecnosport shaft - in fact I like the flopper on the top.

In brazil we are more on the euro style, so all our shafts have the flopper on the top, in fact I have a teak-sea gun in Brazil where the shaft has the flopper on the bottom, that gun is shooting high, I will experiment with that this year, adding an O ring to hold the shaft - This is not going to be the omer o-ring since we can't get that here, but I would think a regular o-ring should work.

The one80 would be the perfect reel for the Cayman 130, killer set up.
 
Hi Mark, the effect of depth on pneumatic performance is real, but possibly over rated as a problem. Any change in ambient pressure changes the pressure differential acting on the piston that will be pushing the spear out. Every 10 metres down adds an extra astrosphere of pressure due to the weight of water above you. As the gun was pumped up at normal atmospheric pressure at the surface and was also loaded there (if you are a freediver) we can just think of one atmosphere being subtracted from the charge pressure in the gun for each 10 metres of descent. So if the gun had 20 atmospheres in it (20 Bar) then at 40 metres of depth it would be shooting as if it only had 16 Bar in it, at 30 metres down it would be 17 Bar. If you plan on shooting deep then you can always add extra air pressure to the gun before you start, all "Sten type" layout pneumatics can be taken up to 30 Bar with their 40 mm diameter air tanks which give a relatively low compression ratio (cocked pressure is naturally higher than the charge pressure). Although the manufacturers do not recommend it, their guns can be taken up to 40 Bar, at least the older Sten models could be, but of course the guns are very difficult to load at that pressure level.

The Mamba type system is less affected by increasing ambient pressure as the pressure only acts on the spear diameter, not the piston diameter, which is the same as the inner barrel diameter. This is because the water cannot penetrate the inner barrel to reach the piston's front face provided the vacuum barrel kit seals keep it out. I wrote about this aspect in the "vacuum-barrels-aka-dry-barrels" thread.

Fitting dry barrel kits to pneumatic guns increases the potential for higher stresses on the gun unless you reduce the charge pressure, which is what most users do, as that keeps the muzzle impacts down to an acceptable level when the piston hits the end of its travel in the gun. The kits prevent the inner barrel from acting as a water pump, hence no back pressure on the piston. My own thoughts are that such kits only became practical with better spears that kept their exterior surfaces. Most of my older pneumatic spearguns had cadmium plated spears, they eventually corrode as the cadmium is used up, nothing too bad, but abrasive to sealing "O" rings sliding on them. Spring stainless steel spears certainly make sliding seals on the spear surface more reliable and saves on having to periodically rub spears down with "wet and dry" paper to maintain their smooth surface.
 

This is true for muzzle loaded pneumatic spearguns as the insertion stroke of the spear is generally limited by the arm reach of the diver and the length of his body to hold the grip handle against his foot. Loading and cocking of the pneumatic speargun occurs in the same motion. That means such guns usually shoot shorter spears than band guns of equivalent power, while the latter also have the advantage of being cocked from the rear end which increases the safety of the user. However it is not true for muzzle loaded, lever operated hydraulic (hydropneumatic) spearguns. These guns separate spear loading and cocking into two separate tasks, just as a band gun does. The guns have been made up to 150 cm spear propulsion length, which places them amongst the most powerful spearguns ever made for their size. You do not have to use all the power, just limit the number of lever strokes per shot. Working the lever is the equivalent of progressively drawing back all the bands simultaneously on a multi-band rubber gun, but it is not about pumping the gun up to operating pressure as the guns start off at 100 Bar. They need to have the higher initial charge pressure because the inner barrel diameter is small, usually 9 mm or 10 mm.
 
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The correct answer is 18.6 Bar, provided there is a true vacuum in the inner barrel. The 16 Bar will be acting on the spear cross-sectional area while the 20 Bar will be acting over the annular area represented by the cross-sectional area of the piston less the cross-sectional area of the spear. The cross-sectional area of the 6.5 mm diameter spear is 33.18 sq. mm., the cross-sectional area of the 11 mm barrel piston is 95.03 sq. mm. That means the "annular piston" area is 61.85 sq. mm. If you calculate the pressure times the cross-sectional area for each element the propulsive force for a dry barrel gun compared to a wet barrel gun at that depth produces an advantage of 16.3 %, which equals 2.60 Bar. The other thing to remember is that there are some muzzle friction penalties with the dry barrel system that are not present with the wet barrel gun, but not enough to offset the ambient pressure shielding advantage of the dry barrel gun. Also dynamically created back pressures in the inner barrel are eliminated with the dry barrel as restricted water outflow in a wet barrel gun creates a pressure that opposes the force driving the piston. For the "Airbalete", if the muzzle ports are effective in minimising the resistance to the water exiting that gun's inner barrel, then the back pressure may be nearly zero. The mass and volume of water to be accelerated is relatively small inside an inner barrel if the spear to inner barrel clearance is kept small, hence the use of 11 mm barrels in guns like the "Cyrano" and "Airbalete".

P.S. 19.6 Bar would be double counting the effect of the vacuum in the inner barrel, so your original figure was correct.

After discussions with Tromic I realised that I should have used the absolute pressures, not gauge pressures. The value of 18.6 Bar then works out as 19.25 Bar relative to the ambient pressure at that depth; Tromic correctly indicated earlier that the number should be larger. Gauge pressure shows air pressure relative to 1 atmosphere at the surface, so you have to add one atmosphere to a gauge reading to obtain the absolute pressure. This is necessary because we are now talking about a vacuum in the gun (less than one atmosphere in the inner barrel). Here I have assumed that the inner barrel pressure forwards of the piston is zero. To use the gauge pressures, rather than the absolute pressures, I should have used -1.0, not zero for the inner barrel pressure. The advantage figure thus changes from 16.3% (see above) to 20.3% which equals 3.25 Bar, not the 2.60 Bar that I previously indicated.
 
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Reactions: Mark Laboccetta
Tromic's calculation method is certainly the simplest way to evaluate the ambient pressure shielding effect of the dry barrel, but I wanted to calculate the respective cross-sectional areas for another reason and that was to estimate the mass of seawater in the inner barrel of a wet barrel gun. If we take the 6.5 mm diameter spear and 11 mm diameter inner barrel example then the volume of water contained in the inner barrel will be 6,185 cubic millimetres for every 10 cm of inner barrel length (from annular cross-section 61.85 x length 100). The density of seawater is around 1025 kg/m3, so the weight or mass of a 10 cm long annular column of seawater for this spear and barrel combination is 6.34 grams. For a speargun with a 64 cm long inner barrel (Airbalete 90's piston travel) that works out to 40.58 grams of seawater (6.4 x 6.34). That mass of water compares with 267 grams for the spear (there is also the mass of the sliding piston to consider, but I am ignoring that here), however the annular column of water being pushed by the piston reduces as it progressively exits the inner barrel at the muzzle openings. The mass of water to be accelerated in the inner barrel is greatest when the piston first starts moving, while the mass of the spear being accelerated stays constant. With zero back pressure in the inner barrel accelerating this mass of water is all that you would have to worry about, which is the best result that the "Airbalete" could achieve. The water represents about 13% of the mass to be propelled initially in the gun (neglecting the mass of the piston), the mass of water reducing linearly to zero when the piston nose passes the end of the inner barrel just before it slams into the muzzle shock absorber.
 
Reactions: devondave
popgun pete said:
...
The other thing to remember is that there are some muzzle friction penalties with the dry barrel system that are not present with the wet barrel gun, but not enough to offset the ambient pressure shielding advantage of the dry barrel gun.
...
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Pete, thank you for your answer. I agree with almost everything you said. Just to remember there is no muzzle friction in the version of tomba where the tubing is at the shaft (the latest tomba, for 7 mm shaft). There is only some additional drag caused by the tubing and the plastic shield in front of it. In any case the vacuum barrel system is better than the wet barrel system, especially at depth.
Regards, Tomislav
 
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Thanks for the strait forward clarification. This is useful information. 40 meters is a bit of an exageration, at least for 99% freedivers. Adding 1-2atm of pressure to compensate for the difference seems like an easy fix.


Clear. So considering most reduce the pressure of a dry-barrel gun compared to not doing so in a wet barrel gun there isn't much of a net gain anywhere from what I can tell.
 
The bigger picture is that, at least here in America, 25/1 is the approx. ratio of band guns to airguns sold. We routinely get calls from 1st time buyers asking if they have to re-pump it after every shot, and or if they didn't call us they pumped it w/o reading the manual assuming it came w/o air (new guns come with air) and damage followed. Or they tried it out of the water first...boom goes the piston + oil everywhere. I returned a call of a surgeon last week who bought an AIRbalete and had no idea how to use it who also wondered if he had to put air in it after each shot, 1st pneumatic. The knowledge and the experience level of this market (speaking USA) would not be conducive to more technical pneumatics as the AIrbalete appears to be fairly complex for most divers new to them. The users of dry barrel modified air guns are a fairly small fanatical and technical bunch (mostly in Europe) who will exercise more caution and watch the wear and tear of the o-rings and sand in the seals as they understand the innards of the guns very well and are comfortably taking them apart and servicing them. The average weekend warrior will not. The reality of the market and the small gains described here would not make it worthwhile for any serious company to adopt into their production w/o running the serious risk of post purchase customer service nightmares. The AIRbalete is even lower maintenance than standard pneumatics thanks to the absence of oil.

I realized following your great breakdown you considered a 6.5mm shaft rather than the 6.75mm shaft which is stock on a 90 AIRbalete. At depths of 15-30 meters I should point out most divers would use a 7mm shaft in which case the volume of water in the piston tube would be reduced even further all else being equal. Using the 90cm AIrbalete as an example one should keep in mind that realistically it would be used in less than 15 meters (it’s a short gun), where the pressure effecting the piston tube water column would be less significant (I think negligeable) as you described. Either way even at great depths as mentioned earlier a few pump strokes would make up the difference.
 
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Mark, I only used the numbers that Tromic provided, the basic intention was to put an order of magnitude on the various effects rather than divers simply guessing them to be big, small or insignificant. I realised the shooting depths used were too great, but again it showed the magnitude of the ambient pressure effect on pneumatic speargun performance and that it is nothing really to worry about.

What you say is correct, I wish I had a dollar for each person who has asked me whether I have to pump up my pneumatic gun for each shot. Unfortunately many divers figure that they do not have to read instruction books, even though the important information is in only a few paragraphs at most. The companies should put a brief list of bullet points on a removable sticker on the guns, that way divers could see the information at a glance, especially as they consider whether to pull it off or not. Another educational tool would be a DVD with each gun, or maybe something to view at the dive shop. Anything would be better than the mix of fact and rumour that circulates in the absence of real information.

Basically it is all about marketing the pneumatic speargun properly. It should not be left to people reading forums to find the information (the same old questions are asked ad infinitum), they should be able to get it up front in an easily assimilated fashion. That comes down to increasing the marketing (as distinct from sales and advertising which are only some aspects of marketing) effort to properly inform prospective purchasers of what they are buying and the advantages for them. Then you and everyone else in the trade would sell more pneumatic spearguns.
 
Reactions: spaghetti
"But" - I am sure that forums do help folk to understand how pneumatics operate because I must of told a thousand myself!
I guesse the main misconception of dumping the stored air stems from the land based break barrel air riffle?
 

Pete, I started using a pneumatic as my first spergun 20, no gosh sad to admit 24 years ago. In Sardinia that is what everyone used at the time, I had a 50cm Technisub. It was more strait forward to me than a band gun because it was explained to me right off the bat. Your knowledge and history of pneumatic eclipses mine by a long shot. Pneumatics as far as I can tell have done a backward evolution having evolved in the 60-70's to having remorphed from a technically advancerd speargun (which it is) to old school clunkers and now back again to the new and hi-tech. My father, yourself probably and many guys that spearfished in the 60-70's know a lot more about pneumatics spearguns and their inner workings than most experienced divers know today because they were much more common. It's widespread use has been amiss since the 90's and they're no longer trendy. It's partly for this reason that the AIRbalete project opened up the history books and went back to see of the dozens of models out there, what worked and what didn't work prior to developing the theme for the AIRbalete. Omer has attempted to put a twist on the classic pneumatic and re-ignite the excitement that a high performing pneumatic speargun can bestowe while spearfishing. Most likely it won't suddenly replace the widespread use of band guns but the AIRbalete has definitely reignited a fire in the pneumatic circles as is evident by this post and by it's market penetration, for it or against it. This ultimately stimulates the enthusiasts of this sport into rediscovering what has been a dying breed for a long time or an existing technology they didn't know about. Aside from re educating the consumer out there this is the exciting part.
 
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Reactions: spaghetti
Well we know many people are interested in the "Airbalete", just look at the number of views of this thread; 12,318 at the most recent count! This may be a record for a particular thread concerning a single speargun model. Even if only a fraction of these readers bought one of the guns that would be a lot of sales!
 
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