Greetings from Austria

Discussion in 'Welcome & Introductions' started by Markus Oswald, Jan 9, 2021.

  1. Markus Oswald

    Markus Oswald New Member

    My 3rd generation DIY aluminum pumpaction repitition compact slingshot "device" is getting quite nasty (70Joule) and there might be possibilities to even improve it further.
    Especially the efficiency is actually only around 50% (due to cold rubber bands) and some havy rollers,..etc...
    As there are so many guys working on similar things , ..I'm sure there could be some interesting discussions on physical limits and so on I'd like to participate.

    some data of my actual "device":
    rubber powered (10 parallel theraband silver on each side)
    transmission ratio to bow string 1/4
    push & pull energy storage
    frame material : Aluminum
    size: 80cm*20cm*20cm
    stroke length 55cm (pusch&pull)
    bolts: DIY 27.5g 10mm quadratic aluminium + steeltip
    magazine (up to 10bolts , so far only used 5 DIY)
    bolt velocity 70m/s
    bolt energy 70J
    efficieny about 50% (depending on temperature,...)
    overall weight 2,8Kg

    Lets see how to improve this! :)

    best regards
    Last edited: Jan 9, 2021
    Algstone likes this.