my grandfather was working on a similar project and it works the samw exact way but with different workings looks really good i want to see what this design can do
Working with a partner in my Physics class for a projectile motion project. We need to make a machine to launch a golfball as far as we can. Over 15ft gives us an A. After seeing the simplicity and effectiveness of this design, I think we'll be trying to make something similar. I think we 'might just' make it over 15ft.
@jlasud: Normally your intuition would be right, and certainly that's what I would have thought a year ago, but I've been measuring rope stretch, and it behaves like a really stiff rubber band. Some energy is lost in the rebound, but not that much. I've tuned this treb with the rope bounce included, and you will notice how stationary the CW is after the throw. Recent shots give overall efficiencies of 42% for a 1087:1 CW to projectile mass ratio - not bad.
One thing i noticed while slinging rocks with a traditional sling,is that a sudden jerk is way less efficient,than a smooth,relatively long acceleration.Of course slinging is different ,than trebuchet physics but the throwing arm,sling and acceleration work the same way.Also i suspect that the rope absorbs quite a bit of E.And perhaps a longer arm with a smoother acceleration would work better with this treb.I'm no scientist,just my observations,and my 2 cents.
@Axecutioner64 : Efficiency measured on this shot was 31%. Simulation says it should be just about 51%. Doesn't look like much energy is left in the system after the throw, so I've got some work ahead of me figuring out where it falls short.
Impressive new design! Good luck scaling this up to baseball size, though. I can see a lot of problems with heavy weights dropping hard like that. What's the efficiency like on this?
my grandfather was working on a similar project and it works the samw exact way but with different workings looks really good i want to see what this design can do
Working with a partner in my Physics class for a projectile motion project. We need to make a machine to launch a golfball as far as we can. Over 15ft gives us an A. After seeing the simplicity and effectiveness of this design, I think we'll be trying to make something similar. I think we 'might just' make it over 15ft.
@jlasud: Normally your intuition would be right, and certainly that's what I would have thought a year ago, but I've been measuring rope stretch, and it behaves like a really stiff rubber band. Some energy is lost in the rebound, but not that much.
I've tuned this treb with the rope bounce included, and you will notice how stationary the CW is after the throw. Recent shots give overall efficiencies of 42% for a 1087:1 CW to projectile mass ratio - not bad.
One thing i noticed while slinging rocks with a traditional sling,is that a sudden jerk is way less efficient,than a smooth,relatively long acceleration.Of course slinging is different ,than trebuchet physics but the throwing arm,sling and acceleration work the same way.Also i suspect that the rope absorbs quite a bit of E.And perhaps a longer arm with a smoother acceleration would work better with this treb.I'm no scientist,just my observations,and my 2 cents.
@Axecutioner64 : Efficiency measured on this shot was 31%. Simulation says it should be just about 51%. Doesn't look like much energy is left in the system after the throw, so I've got some work ahead of me figuring out where it falls short.
Impressive new design! Good luck scaling this up to baseball size, though. I can see a lot of problems with heavy weights dropping hard like that.
What's the efficiency like on this?
@idvance01 how high would the weight have to be to be around 100% efficiency