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Thread Status: Hello
, There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
It can take a long time to get an up-to-date response or contact with relevant users.
pullDistance / (1 - pre-stretchFactor) / pulleyFactor / (desiredStretchFactor - 1)
So for for example my 82cm invert, which has an effective pull of 82cm in it's current setting, with a 300% stretch and 15% pre-stretch it would be:
pullDistance / (1 - pre-stretchFactor) / pulleyFactor / (desiredStretchFactor - 1) =
82cm / (1 - 0.15) / 2 / (3 - 1) = ~24 cm
Then of course mount the rubbers so that they are pre-stretched at your desired percentage.
Now I don't think precision will matter. After a few uses the rubbers become stretched anyway, messing up your hard work and precise calculation. The most important is the factor-2 of the pulley and that contrary to classic guns you have to take the whole pullDistance in account, not 2/3 of it.
* The above is for a single strand of rubber. For MVD you'd need 6 strands for the factory setup. If you have a gun where one or more of the bands loop around an anchor (Alemanni?), then of course it would be half the bands and twice the lenght for the looping bands.
So for for example my 82cm invert, which has an effective pull of 82cm in it's current setting, with a 300% stretch and 15% pre-stretch it would be:
pullDistance / (1 - pre-stretchFactor) / pulleyFactor / (desiredStretchFactor - 1) =
82cm / (1 - 0.15) / 2 / (3 - 1) = ~24 cm
Then of course mount the rubbers so that they are pre-stretched at your desired percentage.
Now I don't think precision will matter. After a few uses the rubbers become stretched anyway, messing up your hard work and precise calculation. The most important is the factor-2 of the pulley and that contrary to classic guns you have to take the whole pullDistance in account, not 2/3 of it.
* The above is for a single strand of rubber. For MVD you'd need 6 strands for the factory setup. If you have a gun where one or more of the bands loop around an anchor (Alemanni?), then of course it would be half the bands and twice the lenght for the looping bands.
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