Engineering Projects/Rubberband gun/Howard Community College/fall2012/p3-503-cq

Problem Statement

Improve the design of the rubber band gun and attempt to get rid of any deficiencies the rubber band machine gun might already have.

Team Members

Cooke

Qazi

Summary

Through out project cycle 3 during our work with the rubber band gun project we have tried to fix a couple of problems the previous team had. For example we removed the drive shaft that was causing the "wobbly issue" and are worked on trying to improve that or replace it as a whole. We also found the wooden pegs to be troublesome at the back of the barrel and the guns front legs themselves to be not equal to each others lengths causing the gun to be slightly slanted. We worked primarily on the drive shaft however and we have made good progress.

Poster

Project Poster
Our Poster

Story

Week #1

- We are working on getting the rubber band machine gun from wobbling. When attached with a drill it jerks back and forth and we need to address this problem. It's basically a problem with the motor part of the gun to which the electric drill is attached.

Week #2

- We are working towards fixing the wobbly issue of this rubber band machine gun. The wobbly issue is basically the jerking of the gun and it actually jerks back and forth due to the barrel of the pulley system not being straight.

- We created a video showing the issue that is happening with the gun regarding the "wobbly parts" and edited it to enhance the viewing experience for the viewers.

"Wobbly Parts" youtube video: http://www.youtube.com/watch?v=57CqtkBVo_Q&feature=youtu.be

Some Pics we took during our work on the rubber band machine gun in week #2

Drilling	Crank Shaft taken apart

pegs	unevenness

- We are researching a replacement for the barrel of the crank shaft of the rubber band machine gun. A metal rod of some sort would eliminate the problem we keep having with the hole in the barrel not being drilled straight and causing the entire gun to jerk back and forth when the electric drill is attached to it.

- We made a quick picture guide as to how ball bearings work and their functionality. Also found out that they are our best bet to get rid of the wobbly issue. Use ball bearings and a metal rod to replace the current drive shaft that we are using/trying to fix. Here's the 4 picture guide:

The wheel	The ball bearing	Reduction of frictional forces	Functioning end product
	The ball bearings are balls inside the raceway of the entire piece that reduce friction	Friction is drastically reduced as smooth balls rolling cause less friction than sliding rings	The final product is a well lubricated moving part of the bigger machine

Week #3

- We used some different parts to try to enhance the rubber band machine gun

- We also tried to fix the wobbly parts by changing out the system in which the drive shaft consisted of. We tried to take out the entire wooden part as a whole and instead use one metal rod type thing that goes through the entire part of the gun. This will theoretically remove the entire wobbly issue as a whole and hopefully make the gun work efficiently as a whole with out the gun jerking back and forth.

- We took pictures of the parts that we used or attempted to use to better enhance the rubber band machine gun

The box within which we found the skateboard wheels and the ball bearings within	another view of the box	Another skateboard part that we thought about using somehow for the rubber band machine gun	another view of the part

Assortment of parts	Skateboard wheels	Back view of the skateboard wheels	An example of how we were trying to use a screw or a metal rod to put through the wheel to use as an axle to power the drive shaft part of the rubber band machine gun

Week #4

- So far during week #4 there was a picture diagram/guide made to show the different assortments of drill bits available and a bunch of research was done as well on drill presses and other tools and machines of that sort.

here is the picture guide showing the different types of drill bits:

Each row contains a set of pictures. Every new row has a different type of drill bit and the same drill bit remains only within the row that it is in

Overall look at the Drill bits There is a wide variety of different drill bits that are available, most of which have specific uses. Some however are universal and can be used for any purpose or at the very least can be used for more than just one objective.

This is the original Drill bit.	Can be used for drilling steel, copper, brass and other hard metals. Can also be used for wood. This is one example of a drill bit that can be used for a wide variety of purposes.	The end is quite simple

This drill bit can be used to drill through timber.	This drill bit has a spike at the end which enforces it's position when you are drilling using this drill bit and prevents sliding and other factors that may disrupt drilling a straight hole and causes a straight and really clean hole to be drilled.	When the spike goes in to the wood, the drill bit and the drill won't wander so you get a really precise and accurately drilled hole.

This drill bit is also used for timber and other really hard woods along of that nature.	This drill bit as you can see is very wide across and drills in a really wide hole as a result	The thinness of the drill bit allows it so efficiently produce the hole that you are trying to create.	This drill bit can be used for many things. One of the many things it can be used for is if you are trying to create a large hole for a door knob or something like that.	This drill bit can also drill the hole in quite a bit of a hurry as well.

	This drill bit has a pilot hole at the end and it ends up drilling its own pilot hole. This drill bit can handle just about any job you use it for.

		This drill bit is good to have in the tool box.

		This is another example of a set of drill bits that one can buy from a hard ware store for his or her tool box

Decision List

None

Material List

- Wood (Free)

- Bolts, screws, washers etc... (Free)

- Electric Drill (Free)

- Skateboard wheels and the ball bearings within the wheels(Free)

- Metal rod (free)

Software List

None

Time

23 Hours

Tutorials

"Wobbly Parts" Issue Video

Next Steps

- Enhance the rubber band machine gun further by:

Improving the drive shaft part of the rubber band machine gun

Replace some of the wooden parts that are susceptible to breaking with better materials

Replace the wooden pegs at the back of the barrel with something more proper and that will work better

Level the gun by making both of the front legs the same length

Add gripping on the gun at the bottom of it to prevent sliding on smooth surfaces

Adding a laser to it for better accuracy when firing