Engineering Projects/Rubberband gun/Howard Community College/fall2012/p1-503-flq

Problem Statement

To create a working model and experiment with the different variations of rubber band gun

Types of guns to explore:

- Basic single firing rubber band gun

- Semi-automatic rubber band gun

- Automatic rubber band gun

We want to make 3 different types of guns in order to explore the different options we can expand into such as a single firing rubber band gun, a semi automatic rubber band gun as well as a automatic rubber band gun. After we each make one of these three guns we hope to advance into the project by focusing on only one of the projects that we all believe to be the best route to take in order to improve it as much as possible. For example if the single firing rubber band gun is working perfectly fine then we rather try to expand into another project that has more room for improvement. We hope in the end to have 3 working rubber band guns and only have one of the rubber band guns that we could possibly improve and even further expand. For example if the automatic rubber band gun is working good enough we want the next team to be able to add to it with something that is not exactly needed but would ultimately improve the gun such as automatic reload or something.

Team Members

Fantano
Li
Qazi

Summary

We are going to explore the different possibilities of working rubber band guns in order to create working rubber band guns and in the end hope to find many models and variations of the rubber gun such as the types mentioned above: A basic model a rubber band gun, a semi automatic rubber band gun, and one that is a bit more advance than semi automatic and fires at a higher rate and is basically automatic.

Story

Week #0

- We started out the project of making a working rubber band gun by tasking different assignments to the 3 group members. Our first thought was to make 3 different working rubber band machine guns over the weekend and have them on hand available for the next class. We came to class and had three working models of rubber band guns. We have created a rubber band gun that is made out of cardboard with a cardboard trigger and the non usable part of a plastic spoon as a muzzle. The second type of rubber band gun that was created was a semi-automatic rubber band gun made completely out of chopsticks and rubber band guns with some tape as well. The third gun we made is a fully automatic rubber band machine gun that is made out of wood and thumb tacks to hold the rubber bands in place.

Week #1

- The three guns all work but they all need to be tweaked a little bit to work more efficiently and in orer to accomplish this we need to each do some more work over the weekend. The automatic rubber gun needs to reduce the resistance on the firing mechanism so that in the future we can prepare it to be mechanized and increase the rate of fire. The chop stick rubber band gun needs to be improved so that the semi automatic mechanism works better and that it self reloads it to fire the next rubber band in the "cartridge" by it self and in a better fashion. This might require the re positioning of the trigger as well as the actual handle it self. We also need to rebuild the cardboard rubber band gun to make it stronger and make the trigger smoother on firing. We will also play with the different widths of the rubber bands in order to improve the efficiency of all three of the guns.

Week #2

- Two out of three guns are now completed and work properly. The single rubber band firing cardboard rubber band gun works properly and shoots a single rubber band gun properly. The trigger was improved for that gun and the gun was made more sturdy. The semi automatic chopstick rubber band gun was taken apart entirely and put back together completely and the self reload mechanism that makes the chopstick rubber band gun semi automatic works properly and lets the gun self reload properly. We are now going to work on the third automatic rubber band gun. The gun works properly except it had a slight problem with the actual release of the rubber bands due to different variables such as the width of the rubber bands, the placement of the thumb tacks, and the tension produced by pulling the rope to release the rubber bands and cause the gun to fire.

Week #3

- We made picture tutorials for 2 out of 3 rubber band guns and uploaded the tutorials to wikiversity via wikicommons. The picture tutorials are step by step guide to creating either the chopstick rubber band gun yourself at home or the automatic rubber band gun. These step by step guides are easy to comprehend and using these anyone can make their very own rubber and gun, either the chopstick rubber band gun or the automatic rubber band gun made from wood.

Rubber Band Gun Tutorial

Completed rubber band gun barrel system

Rubber band gun firing pins

Bored out end of rubber band gun barrel to house bearing

Bearings for ends of rubber band gun barrel system

Bearing inserted in end of rubber band gun barrel system

Piece of wood with pin to hold rubber band gun barrel system

Piece of wood with pin installed on rubber band gun frame

Installing screw to reinforce rubber band gun barrel holder

Bearing on pin of reinforced barrel system holder

Installing screws to lock barrel system in place to frame of rubber band gun

Barrel system secured to rubber band gun frame

Additional photo of barrel system secured to rubber band gun frame

Pre-drilled holes on front of rubber band gun to add further reinforcement to barrel system holder

Installing screws to reinforce front of rubber band gun

Installing first screw to secure stock to rubber band gun frame

Installing screws to further secure stock to rubber band gun frame

Stock secured to rubber band gun frame

Securing back plate to stock of gun, fully reinforcing the strength of the stock

Completed assembly of rubber band gun

Feast your eyes on this beast! The final product

The engine behind this monsters awesomeness

Another angle

The electric drill input area

For the huntsman with soft hands

For the huntsman with shakey hands. Provides extra grip and maximises friction on smooth surfaces to prevent sliding

Our target practice. In red we have Jim and in blue we have Dwight

Step by step process of making the chopstick rubber band gun:

(Please click on the pictures for a more detailed explanation as to creating and assembling the chopstick rubber band gun)

When done with the chopstick rubber band gun, in order to reload it you must pull a rubber band from the front muzzle of the gun back towards the trigger. While keeping the trigger pulled back at a 90 degree angle with the rest of the gun put the rubber band around the trigger, then proceed to wrap it under the left side of the unburst bar and then around the back handle of the rubber band gun and then finally hook the rubber band onto the trigger. Repeat this 3 more times alternating sides for wrapping underneath the un-burst bar and then for the 5th rubber band just simply pull it back from the muzzle and then hook it on to the trigger simply. This mechanism will prevent all the rubber bands from firing at once and will also help to make the gun semi automatic. Have fun with it, try to hit your cat or sibling with it if you can (Don't aim for the face) :P

Supplies needed: The supplies needed for the chopstick rubber band gun. - Disposable Chopsticks (4 pairs) - Rubber Bands (about 10) These supplies can be found at any Japanese restaurant or store.

Supplies needed layed out so they can be viewed easily: The supplies needed for the chopstick rubber band gun all layed out separately. - Disposable Chopsticks (4 pairs) - Rubber Bands (about 10) These supplies can be found at any Japanese restaurant or store.

Step 1: Take a pair of chopsticks and lay them out. Then proceed to make the mazzle-piece and barrel by cutting 25 mm of the chopstick from the end of the chopstick. IMPORTANT: Only cut the 25 mm off of ONE of the two chopsticks in the pair. Leave the entire chopstick bound together with the exception of the piece you cut off. the 25 mm of the chopstick you cut off = the mazzle piece the rest of the chopstick pair = the barrel of the gun

Step 2: This is what the end product should look like from this step. Notice that the 2 chopsticks are still intact with the exception of just the mazzle piece.

Step 3: Take another pair of chopsticks and cut off 65 mm from the thinner ends of the chopsticks and this time you do want to separate them. The shorter cut off pieces will act as the trigger and the unburst bar while the longer 2 pieces are going to be the handle of the chopstick rubber band gun.

Step 4: Leave the remaining 2 pairs of chopstick intact and then you have all the pieces to make the chopstick rubber band gun. The 2 remaining pairs of chopsticks that you left intact and did not alter in any way are going to be sued as the frames of the chopstick rubber band gun.

Step 5: Insert the barrel of the rubber band gun into the frames and tie them up using rubber bands.

Step 6: Then insert the handles into the back of the chopstick rubber band gun and tie them up with rubber bands as well. There should be three places where you have to fasten the chopsticks together using rubber bands. The furthest back handle piece should make a 90 degree angle with the body of the gun.

Final product: Attach the unburst bar at the top as shown and fasten it with rubber bands. Put the trigger in as shown as well and fasten with rubber bands making sure not to fasten it too much as this is the moving part of the gun and should be able to move without too much friction slowing it down. The muzzle piece is attached to the front as shown and also fastened to the rubber band gun with rubber bands. In order to make the trigger more springy use one or two rubber bands, let it slip into the front of the frames and then pull it back and wrap it around the trigger until it is fastened correctly. The trigger should be able to move back and forth properly with out any problem.

Single Fire Rubber Band Gun Tutorial

First, use pencil to draw and design the body of the rubber band gun, then cut it out, and make 4 of it.

Then use hot glu to put them together, then turn to next step--- make a trigger for it.

see where to put the trigger to make it function. and then start to make its shape.

After shaping it, use hot glu to glu them together.

After making everything for the gun, then put them together and glu it.

Week #4

- So far this final week of working on our first project, the rubber band gun project, we have improved a few things on the rubber band gun as well as doing some other work. The major improvement we added to the automatic rubber band gun is a 2 legged stand for the front of the gun. What this stand allows is to let the user of the rubber band gun to set the automatic rubber band gun on a table or mount it on any stable flat place. This removes the need to have to hold up the entire weight of the rubber band gun as well as improves accuracy for firing upon a selected target. We also added the parts required to make the gun automatic. Now to make the gun work automatically all that needs to be done is an electric drill needs to be put into the side. In the next class we will look for some sort of rubberised material to put at the bottom of the two legs of the stand in order to prevent the stand from sliding around if placed on a smooth surface. We will also try to add anything we can think of to improve the gun over all and add to the gun starting points for the next team to work on this project.

- We added rubber gripping for the bottom of the gun where the gun actually meets the table at the three points it does meet and sort of smooth surface. There is now a rubber tape like material on the bi stand of the gun as well as the back handle area of the gun that prevents the gun from sliding around if placed on a smooth surface.

Videos

- We also tested this bad boy out and made a video showing how effectively the automatic mechanism and the electric drill improved both the accuracy and the discharge of the rubber bands as well as created a video showing how the rubberised grip on the bi-stand effectively prevents sliding on smooth surfaces as well as how the stand acts as a pivot to fire the gun in any direction. It can be adjusted to fire straight ahead, aimed down, aimed up, and of course left and right

Pivot + Aiming:

http://www.youtube.com/watch?v=DjDOSdvGGlY&feature=youtu.be

Firing + Target practice:

http://www.youtube.com/watch?v=IBwp3HCSmiw&feature=youtu.be

Tasks for next class: - We will bring in the gun and all three of us will work on making the automatic machine gun more efficient and make it as easy as possible in order to fire the gun and hold it etc...

Tasks for Week 4: - Work on making the automatic rubber band gun motorized by using different tools in the wood shop such as electric drills, drill bits, and other tools to make the motorized aspect of the gun work properly. We plan to use an electric drill to use as the motor that will pull the rope on the rubber band gun to fire the rubber bands from the wooden automatic rubber band gun.

Individual goals:

Awais

Week #3: find supplies in order to design and manufacture a tripod to hold the gun up and also go out and get a laser pointer to put it on the gun in order to increase the accuracy when releasing the rubber bands from the automatic rubber band gun.

Task for weekend of week #4: Watch video tutorials on how to work the individual parts and tools of a wood shop in order to utilize class time to maximum efficiency

John

Task for weekend of week #4:

- Produce targets to use as target practice for testing the automatic rubber band gun.

- Watch video tutorials on how to work the individual parts and tools of a wood shop in order to utilize class time to maximum efficiency

Task for weekend of week #4: Make small targets to use as target practice for after we make the rubber band gun motorized using the rechargeable electric drill

Tim

Week #3: Take the gun apart and remake the automatic rubber band gun in order to document the gun step by step so the gun can be made by any body and put these instructions on the team page as well as individual pages.

Task for weekend of week #4:

- Construct a side mount to house the motor pulley to make the rubber band gun motorized using a rechargeable electric drill.

- Watch video tutorials on how to work the individual parts and tools of a wood shop in order to utilize class time to maximum efficiency

Material List

1. Already acquired materials:

--> Cardboard - Free

--> Scrap Wood - Free

--> Thumb tacks - Free

--> Screws - free

--> Chop sticks - Free

--> Tape - Free

--> Wooden dowel - Free

--> Screw Driver Bit - From the wood shop in class

--> Electric Drill

--> Rope - Free

2. What needs to be purchased in the future to continue working on this project:

--> Laser Pointer - $5

--> Rubber Bands - Roughly $10

The following are possible materials that the next teams might need depending on the route they take to expand on the project:

--> Supplies to work on the automatic function of the gun (to make the hopper etc..)

--> One brand of rubber band so there aren't any discrepancies in the rubber bands and they are all the same length, width, and made of the same material (which ever may suit the rubber band guns best)

Poster

Project Poster
Our Project Poster

Decision List

Software List

Time

56 Hours

Tutorials

Semi-automatic chopstick rubber band gun tutorial

Automatic wooden rubber band machine gun tutorial

Single fire rubber band gun tutorial

Next Steps

Possible next steps a team working on this project in the future can take:

- Standardize the rubber bands used to fire and test the automatic rubber band gun (good width, length, and elasticity)

- Work on creating a hopper for the gun to use in the automatic aspect of the gun

- Make some sort of gear box so that the gun will fire automatically easier

- Make the grip more ergonomic

- Increase the visual eye candy part of the gun for marketing

- Make a commercial to sell the gun

- Increase the diameter of the rope so that there is less room between each indivual peg on the firing mechanism so there is less chance of a mechanical failure when firing the rubber bands