Smacking Paint with SuperBolt

[steveg]

Yet another analogy

Take an orange and a baseball bat. toss the orange into the
air and hit it, as you would with a baseball
Ooo yuck messy huh?

Take another orange and duct tape it to the bat. start swinging

Take several swings. How's the orange doing?

As long as the ball is more or less touching the bolt when
you pull the trigger the ball is experiencing acceleration
only, no impact at all. I suspect that accelerating to
280fps in 5~10" is a heck of a lot more force than the
bolt applies.

Chopping is of course an entirely different matter

[MantisMag]

ok everybody is wrong! hahaha. you can't use analogies that involve your arm. your arm has mass. therefore no matter how light whatever you're swinging or throwing is there is a limit to how fast you can move it. the bolts will have the same amount of kinetic energy but not the same speed if you do not adjust your pressure. Work=F*D. same force applied over same distance same energy. we have the same force from the air pressure and the same bolt distance. work done to an object becomes kinetic energy. KE=1/2*m*v^2. with the same KE but different masses velocity changes by a square root factor. mass and velocity change at different rates. P(momentum) = m*v so they have the same energy but they don't have the same momentum. the superbolt has less momentum than the stock bolt.

now i'm sure i just confused some people. if the superbolt has less momentum why does it shoot at a higher fps? well that's because it isn't a simple collision. the bolt continues to accelerate for a short distance after it has made contact with the paintball. at this point you could consider the bolt and paintball to be one object. obviously a superbolt and paintball has less mass than a stock bolt and paintball. it's not for long. that's why it's only up to a 30 fps difference.

as for the breaking i don't feel like actually figuring it out but i think even after turning down the pressure to make the velocity match the superbolt would still have a higher velocity at the time that it connects with the paintball. that means that the paintball would have to accelerate faster to keep up than it would with the stock bolt. that's just a guess though. i might be wrong. the rest of this post should be right though. i'm pretty sure i covered everything. if anyone has trouble understanding what i said then let me know and i'll try to explain it another way.

[shartley]

ok everybody is wrong! hahaha.

[Miscue]

When you talk about collisions... you do so in terms of impulse forces for the most part. The longer the duration of collision... the greater the impulsive force.

External forces and impulsive forces are two different things. For instance... drop a steel and rubber sphere of same mass. Both have identical external force acting on it - gravity. However, the rubber sphere will have a longer collision time because it deform much more than the steel ball... and will have a much lower impulsive force than the steel ball.

Comparing this to bolts: If you use a lighter bolt, the force behind it is the same (say 60 psi)... but the bolt being lighter will move faster. You're reduced the collision time, and have increased the impulsive force.

You can also think of it in terms of energy, like someone mentioned:

KE = (1/2) * Mass * Velocity^2

Energy put on the ball increases exponentially with higher velocities... and linearly with mass.

[Bad Dave]

The bolt does not hit the ball, it pushes it. If you filmed the mag breach as it shoots you would see that it is not the bolt 'hitting' the ball that causes breaks but acceleration.

[steveg]

So just how hard is the bolt smacking ?

the pin in the bolt is about .240" that is the inside
measure of a 010 o-ring I couldn't measure the pin.
(maybe Tom could help)

.240 dia = .045 "sq

operating pressure 375 psi * .045 "sq =16.9 lbs
operating pressure 400 psi * .045 "sq =18.0 lbs

these are the forces on the bolt before you pull the
trigger.

some of this force is already canceled by the pretension
on the spring (would need to know the spring rate to figure that out)