Project Vulcan

The EBS-25 "Vulcan" is a new nerf gun released by Hasbro for the holiday season. Folks are buying them up and playing with them, however as they wish to modify them they are neglecting basic ingenuity and elementary physics. Let's investigate.

Belt Modding and Problems to Overcome
Many people find that they can combine multiple belts and feed it through the gun. As you increase each link in the belt, the mass of the belt increases. When you lay the belt across the ground and flat, a normal force acts on the belt and some slight friction. When you "dangle" the belt from the ground, the torque in the belt feeder must work to overcome the extra weight pulling down. In short, if you want to dangle a longer belt, you need to increase the torque on the belt feeder.

Rate of Fire Modifications

While we are increasing torque we might as well increase the rate of fire. To do this you can either replace the motor with a higher voltage one OR do some work to remove the resistance of the belt feeder to rotation (moment of inertia?). The idea is to not have the belt feeder rotate freely (it will reject the belt) but to increase the torque (turning power) on the belt feeder and to have the motor turn faster. In addition to this, changing the spring constant "k" in the plunger mechanism as well as the number of turns "n" and distance "l" will yield a larger displacement of air, thus greater range.

Generalizations

I would love to play with this neat little gizmo, but alas and alack the guns are $39.99 MSRP. I would rather purchase the $20 mechanical rifle and increase the range. Auto is great, but sometimes a simpler non-motor mechanism is much better.