User:CFurby/enes100/Rubberband gun

Link to team page Rubberman

Give instructor top 3 project choice list
I decided to stay assigned to the Rubber Band Gun project.

This week we started to develop our own rubber band gun designs while continuing work on our original model.

Write problem statement
I have been assigned the task of building a gatling-gun style rubber band gun. This rubber band gun must fire rubber bands at a high rate from a rotating barrel driven by a motor.

Assign Task0
For week 0 my assignment was to find potential components for the trigger assembly of the gatling style rubber band gun.

Compare actual work done to Task1
This week I found and purchased a 10-count trigger set on www.rubberbandguns.com. They should arrive later this week.

Week1 Narrative
This week I designed a barrel assembly for the chamber, which will contain the trigger and sprocket, as well as the barrel, which will have a notched end to retain the rubberbands for launch. The designs will become more size specific when I receive the rubber bands and triggers.

Week1 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Assign Task2
For this upcoming week I will determine how much wood I will need and where I will order it from so I may start the construction of the rubber band gun.

Compare actual work done to Task2
I have determined that I will need two sheets of plywood, 8 ft. of 1/4" dowel, and 8 ft. of 3/4" dowel. I will need the plywood to build the frame, the 1/4" dowel to build parts within the trigger assembly, and 3/4" dowel to build the length of the barrel. I will be ordering these parts from TW Perry.

Week2 Narrative
This week I build a preliminary chamber setup using 1/4" dowels, 1/4"x6x2 poplar planks, a sprocket and trigger from trigger set, and a 5/16" dowel. First, I cut the plank into two 5 1/2"x7" planks. Then I drilled three 1/4" holes into one plank at the following locations: 7/16" from the top and 3 5/16" from the right side, 7/8" from the top and 1 29/32" from the right side, and 7/16" from the top and 1 1/4" from the right side. I then drilled mirrored holes on the second plank. I inserted 3 - 1/4" dowels through the holes of one plank. I then inserted the trigger on the middle dowel and the sprocket on the most centered dowel, leaving the far right dowel (closest to the corner) without a trigger piece so it may reflect the trigger back into it's starting position. Then I placed two 1/2" spacers on the front and back of the plank. Once those steps were completed, I sandwiched it all with the second plank by lining it up with the appropriate 1/4" holes. Lastly, I attached a notched 7 3/4" - 5/16" dowel on top of the forward spacer by using a rubber band. Currently, the whole chamber assembly is held together by three rubber bands. Permanent fixture is required for proper operation.

Week2 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Assign Task3
This week I will build as many more firing chambers as the amount of wood I have will allow. I'm aiming for 10 firing chambers total. Once I have the chambers built I'm going to mount them to 3 wooden discs to complete the barrel and prepare it to mount onto a drill motor.

Compare actual work done to Task3
I used a miter saw and table saw to cut the poplar planks/dowels down to form the firing chambers.

Week3 Narrative
This week I cut the poplar planks down to 6"x2" rectangles and used the drilling template to drill uniform holes through all the planks. I also cut the dowels down to 1" pieces to insert into the drilled holes to hold the trigger assembly in between two planks (chamber walls). I ran into a dangerous problem this week with using the saw. I tried making small 1" spacers using the left over wood from the cut planks with the miter saw. Using the miter saw caused the wood to explode and splinter. So I abandoned trying to use the miter saw and opted for a table saw instead. The table saw caused a very similar explosion of wood pieces when I tried to cut. So I abandoned the table saw as well for a small hand saw although, it was very time consuming. I would recommend using a standup ban saw because the thin blade would cut the small pieces of wood without fear of splintering, splitting or explosion. I successfully built six firing chambers. The next step is to cut three discs of wood and six 5/16" dowels to mount the firing chambers into a barrel.







Week3 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Assign Task4
Record what you are planning on doing for the team during the weekend between week3 and week4 of the project here.

Compare actual work done to Task4
Rationalize differences

Week4 Narrative
This week I completed the chamber assembly to the rubber band gun. First, I measured out 3 6-inch hexagons on a piece of 3/8" CDX pine plywood using 120 degree angles that were determined using Pythagorean Theorem. Next, I used a table saw to cut them out. The table saw is the reason I chose the hexagon shape as it is near impossible to cut a well rounded circle using a table saw. A circular shape is very much preferred and I would recommend using a ban saw in place of a table saw. After cutting the hexagons I drilled a hole through the center of all three of them using a hand drill with a 3/8" drill bit.

Once the hexagons were complete, I moved on to glue them to the front and rear ends of the firing chambers I made last week. Unfortunately, the dimensions of the six chambers were all different. This is because it is extremely difficult to cut small wood into precise dimensions using a table saw. Again, for this step, I would recommend using a ban saw for a more uniform fit. So the hexagons did not fit flush against the chambers due to the uneven sizes. To rectify the problem, I attempted evening them out using a hand saw. This was time consuming and not very effective. I opted to not attempt the table saw again due to risk of wood explosion, splintering, and splitting because of the small size of the wood. So I decided it would be best to just move forward with the project as best as I was able. I applied wood glue to the front and rear ends of the firing chambers and attached the hexagons as evenly as possible. The fit was uneven and disproportionate and the assembly needs to be replaced with better cut wood supplies.

Next I used a piece of 3/8" all-threaded rod that I purchased from | Lowe's to thread through the center 3/8" holes drilled earlier. After threading the rod through the center of the chamber assembly I used two nuts on the front and rear of the chamber assembly to hold the rod and chamber in place. The inward pressure of the two nuts also presses the wood together to allow for the wood glue to dry more effectively.

1.)http://www.youtube.com/watch?feature=player_profilepage&v=q3hp79wG-Vs
 * Video Demonstration



Week4 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Complete Project Page
Follow the "project done" format.

Start Next Project Week0 activities
During this week you will perform the week0 activities of the next project.