Compounding and draw curve manipulation.

Discussion in 'General Slingshot Discussions' started by Jim_Holmgren, Dec 3, 2019.

  1. Jim_Holmgren

    Jim_Holmgren New Member

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    As most people know we are losing efficiency with light ammo and fast speed.
    Terotically so should the lighter ammo have the same energy as the slow heavy one but the bands can't keep up.

    So too get high velocities we need too increase the efficiency with delicate taped bands, cutting down on weight and at the same time still sacrifice energy with unreasonably light ammo...

    But with compounding we can "gear up" the speed of the bands, sure we loss some efficency as no gearbox has zero loses.
    A typical compound bow will have a gear ratio of ~1:2 wich means simplified that a 70 pound bow does really have 140lb limbs and those limbs will only need to move half the speed as a recurve and on that they use cams to manipulat the force draw curve too put into more energy into the system.

    So now is my question how do we do it and has anyone experience in this?:)

    If we have a very wide fork would we not get a compounding effect like the rüdiger koltze crossbow? https://patents.google.com/patent/US5720268

    Other systems that I know have been used.
    Levers
    Pulleys
    Vacuum (not realy a compound principle but it should have a optimal force draw curve)

    I know many thinks speed is silly but I want to get past 500fps with 54grain balls and have been looking for info on flight shooting and compounding but I can not find a lot of info...