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Friction trigger
- Thread startertromic
- Start date
Thread Status: Hello
, There was no answer in this thread for more than 60 days.
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It can take a long time to get an up-to-date response or contact with relevant users.
The spear tail stop will hit the edge of the shaft gripper on the way out of the gun. Friction trigger guns date back to the hinge triggers used on very early spearguns and are unreliable, however this one spreads the gripping action over a larger area of the spear shaft. Forward latching guns with the release mechanism at the muzzle could use this system as it eliminates the annular groove in the shaft for a sear tooth to engage, but reliability is an issue if the shaft shoots forwards before you have removed the hand loader as there is no indicating click of a sear lever engaging the shaft.
Forward latching makes it possible to use much lighter piston that require more simple shock absorber. With reliable forward grip-friction latching the design might be more simple and maybe saffer? Before acting on trigger spear could not exit with high speed, because of high degree of friction.?!
There is a new Russian "Wasp" ("Oca") pneumatic gun that uses a friction trigger which builds on the format of a forward latching gun which used to be a very common form of speargun in Russia, e.g. the "RPP" or "RPB" (sold as the "Prizm" in the West).
I found a web-site for the gun here:
http://www.electropribor-penza.ru/catalog/osa.html
I found a web-site for the gun here:
http://www.electropribor-penza.ru/catalog/osa.html
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Thanks Pete. Here is a link: http://www.podvoh.net/forum/apgrejd-ruzhej/1407-apgrejd-pnevmata-rpp-60sm.html?start=120
But this is different from what I try to sketch. Anyway, I am just spending my time not to be boring...
http://podvoh.net/forum/konstruktor...koe-ruzhe-s-fzsm-osa.html?limitstart=0#363557
Another speargun, similar friction trigger:
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Hi!
Other design of friction trigger...
http://fishgun.spb.ru/index.php?page_id=poleznoe&item=fzsm
Though the item in Russian, but I think all is clear on images and clips...
Other design of friction trigger...
http://fishgun.spb.ru/index.php?page_id=poleznoe&item=fzsm
Though the item in Russian, but I think all is clear on images and clips...
This appears to be how the "Oca" trigger mechanism works using a roller and ramp to wedge the spear in the muzzle with the gun cocked.
The shock absorber may be a spring, it looks coil bound in the drawing as the piston is leaning on the shock absorber anvil. As a spring it would push the roller forwards and provide a biasing action. However these guns usually don't have a shock absorber and that "anvil" does not seem able to move independently as it appears to be screwed onto the inner barrel as part of the muzzle section behind it.
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Yes, Mechanix design is a very interesting eccentric swinging cylinder or drum (as in a cable drum) containing an annular groove "friction sear" that binds on the lower surfaces of the spear shaft and whose pivot pin is mounted in a rocking cradle that in turn pivots from the top of the muzzle body. To shoot the gun the rocking cradle is either pulled back or is pushed back by releasing a control rod that prevents it from moving and the pivot pin mounting for the eccentric cylinder can then swing through a short arc which allows the contact surfaces on the eccentric cylinder "friction sear" to move away from the shaft and the spear can then escape. A simplified diagram is attached showing the general principle of operation. The muzzle body, moving parts and springs look like they all need to be precision made items to achieve the necessary clearances and locking action and this results in a very technical appearance despite the simplicity of the basic concept, albeit hidden behind a cover on the completed guns.
No, the spring pushes the roller forward to wedge... The shock absorber is hydraulic only...
I make my designs with accuracy, but some colleges make guns of this scheme without any thoroughness... and they work...
My gun did about 1000 shots with the load strength up to 350N... diameter of spear is 6 mm.
There is no obstacle to continue of exploiting it.
Now I think over the design with a control rod passes inside reservoir and a spear with slider - it is real and already tested...
Friction trigger allows loading the gun of 'any' long and with big strength very comfortably without using any "loaders".
At the same time, the piston is very light and the barrel may be thin.
The standard muzzle body on a pneumatic speargun is basically an extended metal nut with a shock absorber sleeve located inside it. While a floating pneumatic speargun is already slightly nose heavy when ready to shoot any additional moving metal parts for a release mechanism installed in the muzzle would add to this weight, so how light could such a mechanism be made while maintaining the necessary strength? The "Oca" mechanism has surprisingly few moving parts, but the weight of that muzzle depends on the outer body material which supports the single pivot pin for the moving wedge element. In photos this material appears to be plastic and should produce a muzzle of a relatively reduced weight considering the muzzle's additional bulk required to mount the "friction sear" mechanism. Is there scope to similarly reduce weight in your two pivot mechanism without compromising the overall strength of the muzzle? In shorter barrel, non-floating, mid-handle guns any extra muzzle weight is less of a problem, but longer barrel guns feel nose heavy unless counterbalanced at the rear end or the muzzle weight reduced.
Here set of details to add to the standard muzzle body for the friction trigger that holds a spear D8 with load strength not less than 400N
The set weight is about 9 g (titanium eccentric, steel cradle)... The weight of muzzle body might be not more than "standard" one.
The weight of the piston may be 2-3 g, so the shock absorber might be shorter and lighter than "standard".
The control rod can be replaced with wire D1 mm (inside reservoir).
The rear part of the barrel (after the loaded piston) is much shorter at the same accelerate motion, so the gun with the friction trigger may be shorter either.
The barrel may have smaller diameter and weight due to the light piston.
As a result, the speargun with friction trigger might be lighter, shorter and might have better balance then "standard"...
The comfortable and safe loading allows to increase the shot energy in ~1,5 times at equal dimensions...
Or at the equal energy it might be in ~1,5 times shorter...
Depends on concrete design and wishes...
After installation of the friction trigger I load the spear at ~300N insted of ~200N... as now I load using two arms simultaneously.