Pump action sling x-bow
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3,228 Posts
There's a reason I didn't build it and you've hit the nail on the head, zille.
I personally no longer like the idea of levered, geared or pulley driven slingshots because every pivot, slidiny part, swinging arm, pulley and cord adds inertia and friction. What may seem to be superior on paper turns out to be a flop.
Jörg went through this phase himself and he and Tex-Shooter warned me off when I was contemplating it and I immediately saw their wisdom.
I prefer the elegant simplicity of a normal band pulling directly between fork and pouch. It's so frictionless, low inertia and consistent that it's hard to beat in performance and it's so simple, maintenance free and compact that I'd prefer it even if it could not keep up.
I personally no longer like the idea of levered, geared or pulley driven slingshots because every pivot, slidiny part, swinging arm, pulley and cord adds inertia and friction. What may seem to be superior on paper turns out to be a flop.
Jörg went through this phase himself and he and Tex-Shooter warned me off when I was contemplating it and I immediately saw their wisdom.
I prefer the elegant simplicity of a normal band pulling directly between fork and pouch. It's so frictionless, low inertia and consistent that it's hard to beat in performance and it's so simple, maintenance free and compact that I'd prefer it even if it could not keep up.
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107 Posts
definately an interesting idea, could be interesting to look at the chinese repeating crossbow for inspiration, thats a lever rather than a straight pull, it worked well in its time so could be interesting to adapt it. another concern would be getting the ball to sit properly in the pouch, on the design posted it doesnt seem to have one, rather it hits the ball (similar to joergs repeating slingshot design) which i believe imparts less power. i do love the concept of such a design, especially if you could make one easily from simple materials and tools
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2 Posts
Hey everyone, thanks for taking the time to check out my video, its always good to see peoples thoughts on my designs
As far as the firing mechanism goes, the ammo sits back up against the trigger when loaded, so the string does push it down the barrel, unlike Joergs repeating slingshot. However, you are right in that it doesnt have a pouch, which was a design choice to make the string sit behind the trigger easier. As far as power goes, I currently run the bungie cord at enough tension that it sometimes cuts the ammo (Jaffas) in half, so I was thinking if I maybe used a sliding block or similiar in the barrel I may be able to up the power without breaking the ammo. I have no doubt that i could fire 15mm steel balls with much higher power. When i was originally testing it the cord continually jumped over the ball, however after I filed the rails down more it stopped doing that.
I did consider lever action when designing it, however I felt that the complexity wasnt really worth it for the draw weight gain. I really focussed on simplicity and ease of manufacture in design. For example, my jigsaw was out of the house when I made this, meaning I had to cut everything out with a coping saw. Took ages, but shows what you can do. If anyone wants the CAD drawings, let me know, although keep in mind I changed it a little during manufacture...
My next project that I'm working on will be a pistol version of this with a bottom feed magazine. That will probably have to be lever action to deal with the higher draw weight that ill need to get the same power in a shorter barrel. Ill probably be using bands for that one instead of bungie cord...
Cant wait to see what Joerg is going to do with his repeating slingshot crossbow...
As far as the firing mechanism goes, the ammo sits back up against the trigger when loaded, so the string does push it down the barrel, unlike Joergs repeating slingshot. However, you are right in that it doesnt have a pouch, which was a design choice to make the string sit behind the trigger easier. As far as power goes, I currently run the bungie cord at enough tension that it sometimes cuts the ammo (Jaffas) in half, so I was thinking if I maybe used a sliding block or similiar in the barrel I may be able to up the power without breaking the ammo. I have no doubt that i could fire 15mm steel balls with much higher power. When i was originally testing it the cord continually jumped over the ball, however after I filed the rails down more it stopped doing that.
I did consider lever action when designing it, however I felt that the complexity wasnt really worth it for the draw weight gain. I really focussed on simplicity and ease of manufacture in design. For example, my jigsaw was out of the house when I made this, meaning I had to cut everything out with a coping saw. Took ages, but shows what you can do. If anyone wants the CAD drawings, let me know, although keep in mind I changed it a little during manufacture...
My next project that I'm working on will be a pistol version of this with a bottom feed magazine. That will probably have to be lever action to deal with the higher draw weight that ill need to get the same power in a shorter barrel. Ill probably be using bands for that one instead of bungie cord...
Cant wait to see what Joerg is going to do with his repeating slingshot crossbow...
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