High Speed Video Footage - Pure Barrel Breaks

[Jack Wood]

After a discussion in Punkworks, I dug up some footage of what I had previously called Pure Barrel Breaks. The breaks occur in the barrel, the ball is not fractured prior to launch.

However, I am reluctant to say that the ball is breaking purely down to the pressure behind the ball. Obviously that is a compnent part, but I am hoping that you can see there is another influence in these clips.

Jack

[Shane-O]

Very nice footage. How well did the paint fit in the barrel? Looks to me like it was an overbore situation and the ball struck the top of the barrel and broke. All the breaks were from the top of the ball.

[JackandBlood]

well without busting out the fluid mechanics book. Just looking at it ol' Newton's 2nd law. It appears the resultant forces are what's causing the breakage. If Fx is from the marker and -Fy is gravity then -Fx and Fy are causing the breakage. If the barerl is over-bore, or even matched bore, I still think Fy is not the normal force from the bottom of the barrel but instead is a pressure differential. So in this footage it looks like lift and a slight airfoil type effect is occuring. I guess this is the part where density of the pressurized fluid and density of air at ATM comes into play which is Bernoulli's eqn, which I am not looking for the book for =D. I'll have to ponder this some more.

[JackandBlood]

Eh I'll keep throwing out notions until i get an affirmative from Jack =). As the breaks seem to occur consistently at the portion of the barrel just after the threads, I'll go with mis-alignment of breech to barrel. If that were the case then the problem is an inherent disadvantage in the standard way in which paintball barrels attachment markers, via threading. Something we'll have to live with.