Just got my new Mares Sten 11!

tromic · Jun 24, 2011

Alex21 said:
@Tromic: your solution with the balls looks very interesting. Material? Manufacture process? Or do you sell them?

@Foxfish: Length is the issue not pressure. I could still work it at 40-45 bar if I was sure the gun will tolerate it safely. Bear in mind the long guns are much easier to load at higher pressures. Dont know why this is so but the Cyrano 970 at 32 bar is much easier to load than a technisub 700 I used to own at 27-28 bar (was a real spearbender).

Point of interest: that technisub had a thicker shaft which I (at some point) replaced with a Cyrano 750 lighter shaft. The result was thatit was very diffuclt to prime and you had to do it completely straight or the slightest ngle would destroy the shaft but it would take 3-4 legths and the gun itself right out of your hand if you did not hold it firmly enough lol

I think nowadays (having read all about vents and water columns and what not) that possibly the thinner shaft (was lighter and) made the water easier to expel from the barrel... Anyway for whatever reason at 3-4 lengths it would spear a 1 kg mullet swimming away and half turning to look at me twice like a peccania :inlove. It was awsome

I have tried medium intensity band guns wih 2xbands and theyr are nowhere near this sort of speed. I think noise and the need for more experience in guestimating the aim are the only drawbacks of pneumatics.

Talking about noise though if you are with another hunter the noise initial will draw fish from the immediate area often giving a chance for a 2nd catch (though solo there is no time to reload)... Anyway I talk too much...

On the picture there are two types of "balls". The smaller is easier to make and is quite good. It is made from Delrin or similar plastic. But you can make the most simple loader like on the second picture. I suppose you can make it yourself.
The Cyrano is easier to load because it is 11 mm barrel. The shorter gun is 13 mm.

foxfish · Jun 24, 2011

Alex21 said:
@?

@Foxfish: Length is the issue not pressure. I could still work it at 40-45 bar if I was sure the gun will tolerate it safely. Bear in mind the long guns are much easier to load at higher pressures. Dont know why this is so but the Cyrano 970 at 32 bar is much easier to load than a technisub 700 I used to own at 27-28 bar (was a real spearbender).

I have tried medium intensity band guns wih 2xbands and theyr are nowhere near this sort of speed. I think noise and the need for more experience in guestimating the aim are the only drawbacks of pneumatics.

Talking about noise though if you are with another hunter the noise initial will draw fish from the immediate area often giving a chance for a 2nd catch (though solo there is no time to reload)... Anyway I talk too much...

Well if you are happy loading a 110 at 45 bar you are a lot stronger than me
Anyhow, the point is, the dry barrel increases the spear speed, reduces the recoil & dramatically reduces the noise!!
So on that basis you could reduce the size (length) of gun you use....

zmajmr · Jun 24, 2011

Alex21 said:
@Tromic: your solution with the balls looks very interesting. Material? Manufacture process? Or do you sell them?

@Foxfish: Length is the issue not pressure. I could still work it at 40-45 bar if I was sure the gun will tolerate it safely. Bear in mind the long guns are much easier to load at higher pressures. Dont know why this is so but the Cyrano 970 at 32 bar is much easier to load than a technisub 700 I used to own at 27-28 bar (was a real spearbender).

Point of interest: that technisub had a thicker shaft which I (at some point) replaced with a Cyrano 750 lighter shaft. The result was thatit was very diffuclt to prime and you had to do it completely straight or the slightest ngle would destroy the shaft but it would take 3-4 legths and the gun itself right out of your hand if you did not hold it firmly enough lol

I think nowadays (having read all about vents and water columns and what not) that possibly the thinner shaft (was lighter and) made the water easier to expel from the barrel... Anyway for whatever reason at 3-4 lengths it would spear a 1 kg mullet swimming away and half turning to look at me twice like a peccania :inlove. It was awsome

I have tried medium intensity band guns wih 2xbands and theyr are nowhere near this sort of speed. I think noise and the need for more experience in guestimating the aim are the only drawbacks of pneumatics.

Talking about noise though if you are with another hunter the noise initial will draw fish from the immediate area often giving a chance for a 2nd catch (though solo there is no time to reload)... Anyway I talk too much...

Hi, here is more complicated version of easy loader but idea is important, all angles are important too (notice the white plastic part and stainless steel shaft, all is done intentionally).

You can try to make basic version but do all angles as on video.

[ame="http://www.youtube.com/user/zmajmr#p/u/37/qu8lVy5BTSA"]YouTube - ‪zmajmr's Channel‬&rlm;[/ame]

[ame="http://www.youtube.com/user/zmajmr#p/u/34/h5AlD6gbgpg"]YouTube - ‪zmajmr's Channel‬&rlm;[/ame]

And you definitely can load spear more easily with 11 mm piston than with 13 mm piston, F=p*S (F=force, p=pressure, S=surface), imagine same pressure in both guns, let say p1=p2=30 bar. S= surface of piston=r*r*pi=(d/2)*(d/2)*3.14

d1=11 mm= 0.011 [m]
d2=13 mm= 0.013 [m]

1 bar =100000 [Pa]
30 bar = 3000000 [Pa]

F1=3000000*(0.011/2)*(0.011/2)*3.14=285 [N]

F2=3000000*(0.013/2)*(0.013/2)*3.14=398 [N] N= Newton

F1<F2

Let say that 285 [N] is like when you want to pull up 28 kilos [kg] and 398 [N] is like when you want to pull up 39 kilos, but when you use speargun you push spear in to the barrel so load on muscles is in the opposite direction than when you lift some weight.

I hope that now you can imagine why is such difference when you load Cyrano and your other gun

I did not calculate with all decimals, and I simplified that 10 [N] is like 1 kilo [kg].

popgun pete · Jun 25, 2011

Alex21 said:
(a) My father used to own a Drago water cannon (proper bazooka tha one) which was loaded progressively (i.e. you could load 10 cms and realease and it stayed put waiting for you to continue) and has never been able to get used to newer types. I d love to buy him a gun like that!

An "Aquatech" hydropneumatic from the Ukraine functions as you describe. The trigger operates a hydraulic valve locking system, so if you push the spear in and stop then the spear only moves out of the inner barrel for a centimetre or so from where you left it. This movement only occurs because the internal releasing valve does not shut instantaneously. The "Aquatech" gun can be fully loaded in progressive steps or you can pump it with short spear strokes once the spear is fully inserted by pulling the trigger and pushing the spear in first with virtually no effort. A valve in the spear tail (a moving "O" ring on a small shank) lets the spear pull out by moving off its seat, but seals again when it is pushed in. The "Aquatech" guns do not float, but this situation may have changed as my two "Aquatech" guns were made some years ago and the models are continually being improved with lighter constructions in the grip area and larger diameter reservoir tubes. They are very quiet shooters making virtually no noise except for the releasing valve moving back on its biasing spring. You can hear that because the rear of the gun is right in front of you, the only thing the fish is likely to hear is the line slide being collected by the butt on the spear tail as it leaves the muzzle. When operated at high pressure the guns have a very high muzzle velocity, so the fish has little time for evasive action.

Just got my new Mares Sten 11!

tromic

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foxfish

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zmajmr

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popgun pete

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Just got my new Mares Sten 11!

tromic

Well-Known Member

Attachments

foxfish

Silver Smoker

zmajmr

Well-Known Member

popgun pete

Well-Known Member

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