GeckoSub Mirage Evo - And Adventures in 3D Printing Speargun Parts

[popgun pete]

I actually bought that extra grip - but I don't like it at all. It's still an ambidextrous grip and also too angled back for me.

As for years Mares had a good grip shape I don’t why they don't go back to something similar. The rot set in with the "Sten 87" as they put square lines into their "Competition Line" gun making the grip fat and wide like that on an automatic pistol with a double row magazine. They dressed it up with a soft fluoro-green over cover which looked nice but held water to spill over your car boot, or whatever, and most divers took it off for the grey plastic grip underneath. Then with the "Sten 2001" we got the flat-sided handle that was OK but not great, building on the "Cyrano" original rear handle molding.

 

[popgun pete]

I have combined your gun photos and updated the "Mirage Evo" thread on www.apox.ru; now await the fireworks!

It will be interesting to see the comments in the "bear pit" as some there will be fit to blow their gaskets!

 

[popgun pete]

Predictable as ever Vlanik is sceptical of this work (but with no rational comment) and wrapping himself in his country's flag launches into his usual tirade and tries to make it “Russia versus the rest” when in reality the problem is himself and has nothing whatsoever to do with his country. His forum posts are littered with “spoiler” overlays (a complete misuse and misnomer) which actually conceal bad language, crude insults and taunts directed at others, when the forum moderator there should delete them entirely. His warning count, if one was kept without any special concessions or dispensations, would have him ejected from the forum. I only mention this as I expect to see him here soon delivering his usual one-liners in Russian without the courtesy of putting them in English, whereas I always post there, www.apox.ru, in Russian.

 

[popgun pete]

With that out of the way I think the completed gun has an excellent appearance and the white handle certainly sets it off with the black carbon fiber tank and upper rear handle section contrasting with the bright red of the nose cone and the camera mounting bracket and extension arm. I expect that it will provide a strong shot and hopefully will be a stable shooting platform.

Recently I have been looking at a hydraulic surcompressor gun and it occurs to me that on a very long gun part of the tank section could be flooded to add water ballast for the shot in an inner chamber partitioned off and always at ambient pressure. Usually this would be difficult to do, but a carbon fiber tank, which is immune to corrosion, may offer more flexible options than could ever be accommodated with an alloy tank.

 

[Diving Gecko]

I actually have had something similar in mind for a while - using a small lever handle pump built in instead of the pumping barrel.
It's a much more advanced build but if I am going to make a custom CF reservoir it should be doable to fit it in. I had just thought of it strictly as pump to move air instead of the pumping barrel, not water but if I undertake this project, I will definitely ask for advice. As for water ballasting to add mass, my thinking these days it is not really needed. There's such little recoil on these guns it's amazing. My Pathos 100 has more felt recoil by far.

I haven't shot anything big yet but the gun seems to be working. I could come up with a lot of excuses but suffice to say that coming here, completely out of shape and not having dived in a year (with a flu on top) - and then needing to dive deep for the bigger fish it is just not happening. I am not stressing out over it. My dives and general shape are getting better day by day so there might still be time. If not, then I learned some lessons;-)

 

[popgun pete]

As a matter of interest I was recently looking at the patent by James Horlock for a hydraulic surcompressor on a rear handle pneumatic speargun. My misgivings for such a construction are corrosion of the alloy tank from inside, but this concern totally disappears with a carbon fiber tank. Now one additional benefit with some weight in the form of water ballast in the nose of a long and light body pneumatic gun is that this mass would minimize any muzzle flip experienced with a very powerful gun during the shot. For your information I have attached the patent diagram here.

 

[Diving Gecko]

Surcompressors and Practical Use
Ah, I got it now and a year or two back I did entertain a similar thought. I guess, once you start thinking about these things you stumble upon these ideas. I can't recall why I felt a water surcompressor was less appealing to me than one that just moves the air - like in a Mirage. But now that I have spent a day thinking about it, the water version does have some advantages though the MIrage still has one important one.

First of all, you can decide not to use the water surcompressor and still be able to load the gun and shoot it. Let's make it easy and say the pressure, before "water pumping" is 20bar and with a fully loaded surcompressor it would be, say, 30bar. In a similar Mirage, let's say the pressure is at 30bar. Now, I could not load the Mirage at 30bar without having moved the air via the pump first but with a water surcompressor pump starting at 20bar, I could. So, the added power becomes a choice not a necessity which might be really nice.
Also, the water surcompressor version wouldn't need a partitioning bulkhead like the Mirage version would and if we allow the assumption that even a 9mm air transfer bore (like in the Evo/new Cyrano) is still throttling the shot, then no bulkhead would be more efficient.
Finally, the water ballasting effect of a water surcompressor should help tame recoil, though it may not be needed.

But let me backtrack a little and talk about why I have started thinking about substituting the use of the shaft as a pump for a built-in pump of sorts. I realized on my last trip to Indonesia and on this one, too that in certain scenarios a Mirage just takes too long to load. (I sadly have to admit that my friend can load his three-banded Abellan Albacore 130 faster that I can load my Evo Mirage).
We have done quite a bit of drift diving and it's a very specific exercise. In many cases the spot we want to dive is very "small" and the fish are only there with a certain current. So, you drop in, breathe up and dive right when the current has taken you to the spot. Most times, you only get one shot at this. Then you get back in the boat, sail upcurrent and repeat it. The point is, that dropping in and then having to load a gun before the dive becomes frustrating. If you have to load before the dive, you need to sail more upcurrent and it becomes harder to judge the exact spot where you should get dropped. Also, the favorable current window is not open for long either so the more drops you can get in before it closes, the better - dropping closer to the spot gives you more dives. And finally, loading right before a dive in tough waters is not conducive to a long, deep and relaxed breathhold dive.

The workaround is keeping the gun loaded on the boat. And honestly, I am not opposed to it but only when I dive with people and a boat guy I fully trust and you have the procedure down perfect among all of you. But I have been on many boats where we didn't feel like it was a good idea for various reasons so it doesn't always work. Hence, why I am beginning to fantasize about a gun that I can preload on the boat. A Mirage with a lever pump would do that for me. I could do the prepumping on the boat and then just have to insert the shaft and rig the shooting line after dropping in - with zero physical exertion. That would be one advantage of a Mirage air partitioning system over the water surcompressor.

I have thought about the built-in pump for a while and this current trip has reaffirmed that there could be a real world advantage to it - though so far I think it's main advantage is in very specific scenarios like drift diving.
I will let this simmer some more before I decide if it will become the next project;-).

 

[popgun pete]

The water injector in this case that I was thinking of was in addition to the pumping barrel Mirage system. Rather than a surcompressor the idea is to take on nose ballast in a long gun. Now the shorter Cyrano’s with their long snout barrels were nose heavy, but the long Cyrano’s gave no such problems as they had enough tank length to be less heavy at the nose, but not by much when the gun was cocked. Now the advantage is you could add tip weight by flooding that nose area of the gun, but could dump the water when you emerged after the dive. On some occasions you may want all the gun's buoyancy, so you need to be able to optimally let water in or keep it out. Think of it as a trim and balance adjustment mechanism.

As for loaded and cocked to shoot guns on boats I know plenty of people do it, say if you are shooting a Marlin the boat crew uses teasers and skipping lures to bring the Marlin to the boat. Then you with your gun already cocked jump in, get your orientation right, watch the Marlin making passes and pull the trigger as all the planets align and then dodge the rush of floats and capture gear as the Marlin takes off, with or without full helm control. Loaded guns on a boat are really risky, guns can be trailed with the business end pointing at the water. Or attached to lines kept on the side of the boat, but you don't want them torn away of course. Guns must be discharged before getting back in the boat, so triggers have to be pulled whether there was a real shooting opportunity or not.

 

[popgun pete]

You can see why carbon dioxide guns were so popular and in their heyday were used to wipe out many long-lived territorial fish such as Gropers and Cods. Now I shot them (the fish, not the CO2 guns) as well, but only enough for food supplies for the next day or so as with nowhere to store the excess meat, or eat it all if it was a giant, even giving it away to grateful camping ground recipients would not get rid of all of it. But on the boat the big carbon dioxide gun was completely harmless with the gas supply shut off by screwing the tank valve closed, unless you took someone’s eye out with the spear tip when foolishly waving the gun around. The more advanced gas guns than the Pelletiers could be filled in the firing chamber, the bypass collar opened and the spear shoved down the gun barrel and then the gas shut off again. With those guns a shot was ready to go, whereas in a Pelletier, which is an extremely simple gun, once you unscrew the rear tank by twisting it the gas fills up behind the spear. Thus for big fish you were ready to shoot once you twisted the rear tank when you jumped in the water and the gun instantly charged up. With these guns you have 900 psi at your command, the reason the big Alcedo “Hydra” guns muscled out the gas guns in some situations was they had 1,400 psi plus on tap! KABOOM spearfishing days which, when greatly overdone, nearly sent the sport backwards when fish were shot, weighed, photos taken and then dumped.

These guns belong to Cyril M, who supplied the photo

Although there appear to be a lot of parts here, the Pelletier is a very simple gun as the sear lever cum trigger holds the spear and when the tank is twisted a valve releases gas which fills up behind the spear tail. Then you close the valve, otherwise when you shoot all the gas will escape from the rear bottle or gas tank. In the water you open a bypass valve so water shoved by the spear being muzzle loaded exits through that bypass valve and then you briefly open the rear tank valve to purge the last of the water out of the gun, close the bypass valve and then pressurize behind the spear again by opening the rear tank valve, after which you close it again and you are then ready for the next shot.

 

[Diving Gecko]

This current trip is turning out to be a weird one. A few days ago, pretty much on the first day where I felt my diving was becoming good again with better depths and hang time without getting exhausted, I made one mistake when getting back in the boat.

I've always entered small boats by pulling up in a handstand, turning around and sitting down on the gunwhale before swinging my legs in. It's worked better for me than crawling in on my tummy like a beached whale and yes, it looks better, too;-)
But this time, pulling myself up on the gunhwale I somehow lost grip with one hand and landed on the side of my rib cage. Not a huge fall, just from a handstand down but the result was one bent rib.
I gave it a few days rest and went out yesterday but just the effort to load the long airgun messed with my rib so now it's worse than before.
Anyone who ever bent a rib knows it's just about the worst kind of small injury. I'd say way worse than a sprained ankle which is bad enough:-(

On the gun health side of things it's better. There's been some issues but I'll report on those in another post.

I did make a great shot on a medium sized dogtooth tuna yesterday only to see the shaft fall out of the fish...! In the video, the shaft is halfway through, barb fully opened but the fish stutters around, magically closes the barb and the shaft just falls out. I've never seen anything like it and it did make me practice my underwater swearing skills...
I don't know why I have stopped tuning my floppers but I certainly will be doing that again now.
Pathos and Salvimar shafts come with loose barbs and I guess I trusted they do for good reason. Now, I'm not so sure.

I had changed to a normal flopper shaft from my slip tip shaft to make sure I had the most accuracy and penetration but had I stayed with the slip tip I would probably have landed the fish.
Sadly, that fish is shark food now as there was definitely spine damage from a well placed shot:-(

Between my smallest of "falls" and the Houdini doggie I'm feeling like I need to find the local fisherman's temple and say a prayer or two.


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[popgun pete]

Sorry to hear about your tumble into the boat, yeah, jamming your ribs onto immovable objects hurts for a long time, lucky you did not break anything!
Although slip tips save your spears from being bent and the fish working against the shaft and breaking free and are much less bulky than a breakaway tip, I favor the latter as slip tips don't always deploy, especially if they have plunged into sand. If you have plenty of gun power then the only concern with breakaway or detachable heads is the steering effect of the trailing breakaway cable if you don’t have it on a second slide ring, but their long double floppers keep the fish on the head which is connected by steel cable to the shaft.

 

[Diving Gecko]

My feeling - but it's only that as I have not had this setup in a pool - is that my slip tip is quite accurate.
First of all there's no wiggle in this particular adapter and slip-tip combo. Also, I had custom slide rings made and they are substantially smaller than the standard ones. Combined with a necked down shaft (to ø6.5mm), a 7.3mm slip-tip which is slightly smaller than normal and an adapter which is likewise as small as possible it really looks like a low drag setup.
It's rigged with dyneema so no weird, kinked cable to throw the shaft off, either.

My low drag slip tip setup:

Notice how the slide ring is hardly any bigger in OD than the shaft and likewise the adapter is quite slim:

But that said, the reason I changed to a normal shaft is because I had already had two doggies tear off the slip tip. At least one of those losses was my fault as I shot way too high, just an inch or so under the "top" but at least I'm fairly sure that fish will survive. The second one was shot similarly high and I think he'll live, too. But I might be able to blame Mares for that one...
So, in the end I guess I just changed mostly for the sake of changing things up a bit and hoping to better my mojo.

But one thing that certainly didn't help and might have caused the second high doggie shot and subsequent loss of the fish: Within a few shots, the trigger and line release interface developed so much friction it seriously hampered my attempts to shoot at will. It most likely cost me a really nice grouper on a deep dive, too when it took two tries to get the shot off.
I have since taken the parts out and polished them for the second time but I think it will only last ten shots or so before the trigger will mess with me again. It was smooth and light yesterday (after polishing) on the beautiful spine shot on the doggie that sadly wiggled off the shaft.

Second round of trigger polishing:

Rigging the shooting line extremely loosely helps for now though with a breakaway setup that's not always easy. One tug on the floatline can put tension on the shooting line and as a result make the trigger much too hard and unpredictable. I think the solution will be to change to a smoother plastic trigger or release or both.
I speculated about this back home but now, after some real world use, I am almost certain: Mares seriously effed up this line release design...:-(

As for the general use of the gun I had one tiny leak at the nose cone from the pumping bore. It could stem from the pumping piston, the o-rings on the pumping barrel or from the cone itself. Since I was not in the mood to try to eliminate the possibilities one by one I opted to change both the cone, the piston and the barrel o-rings (one of which was nicked):

That stopped the leak but then I ran into another issue - the Delrin pumping piston gets stuck in the stainless steel washer at the front of the barrel. Even the original Mirage (with a plastic piston) suffers from this issue. The problem is that the bore of the washer is about 9.1mm to allow the 9mm shaft tail to pass through but the OD of the piston is only around 9.9mm (it's a 10mm barrel). So, there's not really much of a shoulder overlap between the piston and the washer.
Since I had a scuba tank from a nearby dive shop at my disposal I decide to pop the gun open again and change the pumping piston to one Dima made me in titanium long ago. But unfortunately he chamfered the front edge a little so this also gets stuck in the washer a bit.

This issue with the washer is if not a recurring one then at least prone to developing and one future solution would be to go to an 11mm pumping barrel and possibly a 14mm shooting barrel. But if I go ahead with a built-in lever pump instead of a pumping barrel then the piston-washer issue disappears completely;-)


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[popgun pete]

I never had any trouble with the pumping barrel piston getting stuck because my "Mirage" has metal pistons and the pumping piston butts up flat against the metal washer. However to me the real problem is this trigger, now I don't use tight line wraps on my guns and the mono shooting line the CYRANO 1.3 was supplied with got thrown in a drawer as did the weak line slide, so the loading on the line release lever is not very high on my gun which has spectra shooting line. I think that you should keep the metal trigger and make a nylon line release finger patterned on the metal one, then the lubricity of the nylon should minimize friction between it and the trigger. It makes me wonder who is designing and more importantly giving the OK for these flawed guns to be produced. Probably someone surrounded by a bunch of “yes men“ as anyone doing that will only ever know what they already know.

 

[Diving Gecko]

I agree, one metal and one plastic part should do the trick and the line release is the easier part to make.

I have stiff dyneema on this gun, too for shooting line - and it would likely have been less of an issue had I had a reel on it. Then I could have kept the tension very low.

The safety on this thing is nice though. They got that one right. I mentioned that it really pokes into your trigger finger when on (if you are a righty) but wasn't sure I would be able to feel the "warning" with gloves on. But I can - there's no mistaking whether it's on or not. Cudos for getting that right, at least;-)
Not that I have had that many guns but between the ones I have and have tried, this is the first safety I actually like. Others, you can start doubting if it's on or not and you may need to consult a logo, symbol or some letters. But this one just pokes you and ruins your grip on the handle when it's on. Very, very clever yet simple - as I guess the best solutions often are.
On the other hand, the Pathos band gun I brought has an S and an F setting. Is S for safe or for shoot? Is F for fire or free? Or something else completely? Turns out S blocks the trigger so I guess it means S is for safe... suffice to say that for a gun I don't use often I am not really inclined to use the safety. I know that if it was my go to gun, I'd get used to it. It's just not intuitive design.
At least the One Air/Airbalete symbols are a fish and a fish with a strike through.


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[popgun pete]

"S" is generally safe or securite and "F" for fire, although tir in French the usual practice is to use the English terms. A safety is to be used during gun rigging, then you switch it off and leave it off. Mares had to change things when they raised the inner barrel in the gun and the space where the transverse safety slide used to be was taken over by the new line release, so they were forced to place the safety device behind the trigger and higher up on the gun.

It is just as well that the "Sten" has remained unchanged and is still a popular gun as these CYRANO guns are not fully sorted out.

 

[Diving Gecko]

Houdini Doggie
Not the best video but if you freeze frame it, you can see how at one point the shaft is halfway through with a fully opened barb and then the next, the barb is closing and the fish is gone. Had the shot been less of a spine shot, the fish would likely have pulled hard and stayed put against the barb.
Well, back to tuning floppers for sure now.



(BTW, the gun was only at 29 bar for this shot)

 

[popgun pete]

Well the shot from the “Mirage Evo” looked and sounded good, but I think that you should try a breakaway head with some cutting blades on it. The advantage of these is you pull the spear tip off to muzzle load the gun as the loader can just push on the stubby terminal end of the shaft, then you replace the tip on the shaft, it having been dangling on its cable. Tri-cuts and quad-cuts will otherwise do in your loader, although the metal reinforced ones are not easily damaged, but they in turn will blunt your cutting edges at the tip. Also 40 bar should punch right through, but you want your tip to break up things on the way through as shock and nerve damage will take their toll. Otherwise it is like stabbing a fish with a fat knitting needle.

 

[Diving Gecko]

This was the first day I changed from a slip tip to a normal shaft. Had I not, I would likely have landed the fish. But that's life. Lesson learned. Tune the flopper or shoot slip tip shafts.

As per one of the posts above I believe I have a really efficient slip tip setup based around a Spearmaster dyneema slip tip with some customization.
Having used a slip tip with cable before (from Salvimar) I will likely not do that again. The cable kinks way too easily and I feel that can throw off the shot. Also, the slide rings from Salvimar are horrendously big. It's a pity really as the tip itself is really nice, has no wobble and is hardened, too.
But with a bit of work you can convert the Salvi tips to dyneema but they are difficult to get these days. Furthermore, Salvi made a whole batch where someone put all the barbs on the same side as the line... And while they have offered me replacements, they have not yet made a new batch - and it's been more than a year.
So, now I'm using Spearmaster slip tips and while they are a whole lot softer than Salvi's they are designed to use dyneema and changing it out is really easy, too.

 

[popgun pete]

I put your video of the new gun shooting on the "Mirage Evo" thread on www.apox.ru. A picture is worth a thousand words, so they can see the rapidity of the shot and the stability of the gun.

This is the breakaway head type that I am talking about https://www.jblspearguns.com/product/arrowhead-break-away-tip/

A quad blade would be preferable as with high gun power these create damage, which is what you want.

To muzzle load these tips you need a loader that can swallow the tubular receiver end and cable folded over, although the pencil points can be loaded with a conventional loader right on the tip. The loaders that used to double as a muzzle cover such as this Mares version used for the "Titan" guns will fit over bulky items, even pranger heads, however with a pneumatic speargun prangers are hard to extract from the victim as you cannot use a shaft re-inserted in the gun to rip them free of the victim..

 

[Diving Gecko]

Those tips are interesting but seem to be going down a different avenue. Judging from their looks they seem to sacrifice hydrodynamic efficiency for "more damage". For land animals, inflicting more damage makes sense so the prey bleeds out faster. But for fish, not so sure. If we shoot a fish in a soft place with vital organs it might make sense that we want it to bleed out but chances are a strong fish will tear off before that happens. Instead, I'd like a great holding shot or a stone shot and for now, I am going down the path of trying to make the slip tip setup as accurate as possible with the least drag and thus, most penetration.

I'll sit these out for now though I would be interested if others would test them - but I have other more pressing projects ahead;-)



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