These have the potential for tremendous output of bbs.
Posted: Tue Apr 22, 2008 1:34 am
by jon_89
what was the eqaution to figure out fps?
Posted: Tue Apr 22, 2008 1:53 am
by jackssmirkingrevenge
If a 5 inch disk is spinning at 10,000 revs per minute, then a BB at the circumference travels a distance of (2 x pi x radius) - 15.71 inches in this case - in a time of (60 / rpm) - 0.006 seconds in this case.
Therefore if in 0.006 seconds it travels 15.71 inches, in one second it travels ([1 / time for one revolution] x distance for one revolution), in this case 2618 inches or 218 feet, therefore the velocity is 218 feet per second.
Posted: Tue Apr 22, 2008 7:26 am
by JDP12
hmm.. might have to give this a try, perhaps increased rates of fire hmm??? also you wouldn't run out of air, which would be a boon... now how to make it portable.
Posted: Tue Apr 22, 2008 8:18 am
by jackssmirkingrevenge
ilovetoblowthingsup wrote:hmm.. might have to give this a try, perhaps increased rates of fire hmm??? also you wouldn't run out of air, which would be a boon... now how to make it portable.
Again, have a browse through this project - the guy managed to achieve BBMG style performance in a portable package.
Posted: Tue Apr 22, 2008 10:56 pm
by jon_89
For this would I want a short or long barrel? Will a long barrel cause friction thus losing power? Will a short barrel decrease accuracy? What kind of motor would I want to use?
Posted: Wed Apr 23, 2008 12:10 am
by jackssmirkingrevenge
The barrel shouldn't be more than a couple of calibres in length, it's just extra friction. As to accuracy, what's important is that the barrel is as tight as possible and the muzzle is cut at 90 degrees.
What kind of motor would I want to use?
The biggest you can find you want as many revs as possible, because it's directly linked to the maximum velocity you can obtain.
Posted: Wed Apr 23, 2008 1:02 am
by jon_89
Is that 5000 fps even possible? It is stated in the first posts link.
Posted: Wed Apr 23, 2008 1:34 am
by jackssmirkingrevenge
jon_89 wrote:Is that 5000 fps even possible? It is stated in the first posts link.
Theoretically, if you can find a motor that will spin a 2 foot diameter disk at 48,000 rpm. And of course, a disk that will spin at that velocity without flying to pieces.
This concept had been proposed as a weapon of war and some funding was apparently granted by the US military, however nothing concrete seems to have come out of it.