No More Dilemmas What Mechanism To Chose
Crucial for each speargun is its speargun mechanism and its flawless operation. The main criteria for the seemingly simple form of mechanism is its precise construction, which is now made possible by computer controlled machinery and stainless steel.
This speargun mechanism can only be made following the technical calculation of strength of the force acting on the trigger.
So a quality speargun mechanism can not be made without the assistance of a mechanical engineer.
Otherwise you can easily experience very uncomfortable situations such as when meeting with the biggest fish of your life ? and the mechanism fails.
It is also possible for other abnormalities to occur; such as:
- too soft trigger; where the hunter has no sense of when the gun triggers;
- hard trigger instead due to stronger pressure can cause delay on the targeted prey which then results in missed shots. If any worse things than these happen are due to the inadequate and poor quality construction.
Especially self constructors of spearguns often deal with great dilemmas; namely, what speargun mechanism to chose for the gun. The main requirement, besides the proper calculation of the friction, is the carrying capacity of the mechanism, as this holds the harpoon through which the slings? "Power Bands" are tightened.
It is the self constructors who mostly come face to face with conflict when they hastily choose the mechanism and at the same time, have a great desire to produce as strong gun as possible.
That?s why it is useful, when buying the mechanism, to check its carrying capacity with the manufacturer beforehand. It should be at least 2 times greater than the force represented by the sum of all the tightened slings on the gun.
This means, considering the thickness of the sling, that a stretched (tightened) sling creates somewhere between 300 and 600 N force that accumulates linearly according to the number of slings on the gun.
For safe and reliable operation of the mechanism, the slings? force may not exceed half of the calculated carrier load of the mechanism.
Important note: wooden guns? mechanisms vary from the mechanisms that are embedded in the serially manufactured guns made from other materials: aluminium, plastics, carbon ... with the fact that they do not have built-in contact-breakers.
Safety in handling a speargun is, therefore, provided in a manner that the trigger stroke is longer. This is to ensure that the triggering of the speargun is not done accidentally.
Quality stainless steel mechanisms are, therefore, dimensioned in a firm casing that bears at least 2000 N of load, however, the best mechanism bear even over 3200 N of load.
Only such mechanisms will reliably perform in guns of a length of 150 cm and over, on which 5, 6 or more slings are installed.
The duration of such mechanisms is very long although the maintenance is minimal. It is sufficient to wash it regularly with fresh water. The only thing that happens with poor maintenance (negligence) is the sensation of harder triggering as sea salt crystals build-up in the moving parts of the mechanism.
This inconvenience can take place; however, it represents no major concern or a reason for a service or for replacing the mechanism as salt liquefies in water. Also, even "mistreated" mechanisms will, over time, function normally again.
Only the best manufacturers of mechanisms are concerned about the "silent" operation of them. The silent triggering of the mechanisms is usually a manufacturers? trade secret; nevertheless, a layer of soft material is inserted inside the casing on which the hammer strikes and thus suppresses the metallic sound.
As regards the form, mechanisms are divided into two main groups. In the first group there are traditional mechanisms used in the vast majority of serial as well as "custom-made" guns, and in the second group there are inverse mechanisms.
The main difference between them lies in the fact that inverse mechanism with the reverse position of the hammer allows fixing of the harpoon to a few centimetres behind the trigger.
The result is that we can use a 10 cm longer harpoon on the same length of the gun, which is a great advantage. Nevertheless, the benefits also have limitations; therefore, we need to make a compromise.
Namely, I'm speaking about the balance of the gun, made by its carrying capacity and the weight of the harpoon.
This is associated with the slings? dimensions. The kickback (recoil) depends on this when triggering and it affects even the precision of the shot.
Namely, the situation is like this; installation of the inverse mechanism can fool the constructor of the gun in such a way, that he will install a longer, and with it, a heavier harpoon, however, with this the balance of the carrying capacity of the gun will be destroyed; or he will use stronger slings due to heavier harpoons and this will result in strong kickbacks.
If the constructor wishes to avoid such problems, he will have to increase the mass of the spear gun when installing the inverse mechanism.
Of course that leads to another compromise: agility of the gun is reduced, so I recommend serious consideration when making decisions on the type of mechanism for each gun.
The manufacturer of the gun has to establish, in the first place, for what purpose he is building the gun.
The guns are normally divided into those whose usability is narrowly focused (these are guns with greater range and less agility used for catching bigger fish) and in the second group are guns with medium-range and higher agility, which are suitable for different hunting techniques (conditionally also for different sizes of fish, which are usually the most prevalent, at least according to experience).
The vast majority of spear gun hunters occasionally hunt several species of fish, using various techniques and, therefore, wish to use as much a versatile spear gun as possible.