Engineering Projects/Rubberband gun/Howard Community College/fall2011/502 ZSN

Problem Statement

Make a rubberband Gatling gun, and create an autoloading mechanism that allows the gun to fire repeatedly.

Team Members

Put each team members name here with links to their personal page here. Real names do not have to be used.

Summary

Team started with research of potential designs, though none of the team members could think of an effective way to create an autoloading system. There was a general consensus that the rubber band gun should be built first before they begin to focus on the autoloading aspect. A general design was agreed upon, based of a video on youtube: [[1]]. Construction of the gun was limited to the barrel assembly, but was eventually switched to a base for the gun as well as implementation of a motor of some kind. Unfortunately, the team could not locate a motor that could pull the barrel and launch rubberbands at the same time, so a hand drill was used for test fires. On the final day of work, where testing needed to be done, the gun had a tendency to jam as rubberbands would not launch off teir pins, and impede future rubber bands from firing. A solution to either of these problems has yet to be determined.

Poster

Rear view of the barrel assembly

Rear view of the barrel assembly with handle

side view

Close up on handle

Story

The team each worked diligently on the project, making the barrel assembly out of dowels, plywood, and PVC pipe. Most of this work was done in class, although some work was done at the team members' homes. Things were coming together, however time constraints forced the team to rush the body and trigger mechanism during the last week of class. A suitable motor was not found, so test fires had to be done with a drill motor. By the end of the project, it was discovered that the gun had a tendency to jam, this was not fixed due to lack of time.

Decision List

-Original design: team consensus to base design off of design on youtube:[[2]]

-Team made a decision to make the gun a 5 barreled Gatling gun type rubberband gun.

-A suitable motor was not located, so the team made a decision to use a hand drill as a motor substitute.

-When gun continuously jammed, it was decided by the team to sand down the pins of the barrels to allow for less jams, though this idea was not implemented fully.

-The pegs became to short and gun had trouble firing.

Material List

1/4 inch dowels (barrels)

Plywood (variable size, shape and thickness; used for construction of the base and for connector pieces for the barrels)

Rubberbands (ammunition)

2mm sticks (pin material)

1 inch dowel (handle)

Switch (trigger)

Motor (size and power undetermined, did not find a suitable motor for this project; Barrel spinning/Rubberband launching system)

String (thin rope works best; attached to motor and is a part of the rubber band launching system)

PVC pipe (used as a sheath to allow the barrel assembly to spin)

Software List

Google chrome (for research).

Time

Total time in class: 8 hours in class building

Out of class: 4 hours

Costs: $4 for dowel rods

Tutorials

If future teams wish to build a gun based off the design this team based their design off of, the documentation relating to the original design is here:[[3]]

Should future teams wish to pursue a different design, many can be found in action on youtube.

Next Steps

A suitable motor needs to be found, although a hand drill jury-rigged to the base assembly may work. The pins need to be adjusted to allow the rubberbands to fire without jamming, either by way of sanding or by making new pins. An autoloading system needs to be designed and applied to the gun.