Rubbers calcul

We notice on this curve, that a booster of 18 in coefficient 4 will supply as much d energy as megabooster in coefficient 3,5 but will longer last to .Pour copies, it is necessary to pay attention has to put equivalent coefficients so that they work very all together and the restored power will not increase twofold c is as bi-motorizations, c is effective but more binding 
It is thus necessary to know if l we really need all this power which raises évidement problem has the precision to fire has 4 m and still ......

Was him(it) d a rifle is a thing but it would be nothing without the propulsion system of the arrow 

C is has to say luggage elastics .On sees many things, written on the strength exercised by those this, some paintings(boards) are present 

On the Internet but the units can give interpretation(performance), j has errors d thus realized I even the measures has l help(assistant) d a steelyard which 

Unfortunately not exceeded(overtaken) not 50 kg but we notice that the rifles of the business(trade) are only ever equipped very rarely so to speak of

Luggage elastics which free(deliver) more than 50 kg.... It n is no question of solidity but simply backward movement(drop) and acceptable precision, c is d somewhere else for it that j have 

A preference for the fair 20 mm with a coefficient of 3,2 has 3,5 is 45 is approximately 55 kg .Si you want to measure 

  E coefficient of your luggage elastics on the rifle c is rather simple.

L=longueur of the luggage elastic (ring has ring), There existing length enters end of l shell(shells) and the second notch of the arrow 

C (coefficient) =Y / L+1

We notice on this curve, that a booster of 18 in coefficient 4 will supply as much d energy as megabooster in coefficient 3,5 but will longer last to .Pour copies, it is necessary to pay attention has to put equivalent coefficients so that they work very all together and the restored power will not increase twofold c is as bi-motorizations, c is effective but more binding 
It is thus necessary to know if l we really need all this power which raises évidement problem has the precision to fire has 4 m and still ......

To confirm little, the various measures and the calculation made, j used a small software calculating the arrow, and the terminal speed of the arrow, according to the diameter used luggage elastics, their strain and the characteristics of the arrow .On can find him(it) on this link.

      http://www.speargunballistics.com/?locale=en

 Here is some examples of calculation to .Pour to be able to compare the powers, j took a shooting(firing) has 4 m corresponding at the most of what l we can hope with lengthes of rifles used at our home(with us) most of the time

Évidement it n is that very theoretical but it confirms, the simple calculations of luggage elastics and coefficient as well as the impressions(printings) that j had with the roller, only the results(profits) of my 90 seem to me a little bit low(weak), but I n calculated with my arrow Titanium which owes helped well although l we say it especially at first in the first 3 meters..

I thus find for my roller 80 cms: at 4 m an arrow of 5 cms and a speed of the arrow of 40 m/s

                            For my 90 cms: at 4 m an arrow of 10 cms and a speed of 27

                           For my 100/105: at 4 m an arrow of 4 cms and a speed of 44 m/s