Week 9 - Updates

 The remaining tasks left to be completed this week include caulking the solenoid valve, attaching multiple components to the submersible frame, and testing.

Caulk was needed to waterproof the solenoid valve.

The ballast tank, the solenoid valve and the pump were attached to the submersible frame using electrical tape. Below are pictures of the group assembling the frame and of the completed submersible.

Once completed, the submersible was tested at the Drexel Athletic Center. The first trial can be seen below. This shows that the ballast tank system holds pressure and can successfully pump water in and out.

The following video shows the submersible diving and resurfacing in the water. It also shows the effectiveness of the ballast tank in the submersible.

Week 8 - Updates

The physical deliverable for the project is still being worked on. After a discussion with one of the machinists from the machine shop, it was decided that the inner rim of the ballast tank did not need to be removed because the the pipe threading is efficient enough on its own. The ballast tank was completed at the machine shop. Below is a picture of the finished ballast tank.

The ballast tank and the PVC pipes were primed with purple PVC primer and glued together with PVC cement.

 The Purple PVC Primer is shown above and was applied using the brush attached to the inside of the lid.

 The PVC Cement Glue is shown above and was applied in the same manner as the primer.


Below are pictures of our group priming and gluing together the PVC pipes, elbows and endcaps in the submersible frame and the ballast tank.

Attaching the ballast system to the submersible frame, adjusting the motors after testing, and figuring out the ideal water level within the tank are the only tasks that remain for week 9.

 Due dates for the presentation and the final report are coming up. There were no specifications made by our instructor concerning the layout or content when discussed with her. Therefore, our group has decided to generally organize the report in the same format as the template used in our prior engineering courses.

Week 7 - Updates

The ballast tank is on the brink of completion. A trip to the Machine Shop was planned to cut the inner rim of a large PVC pipe off to ensure a smooth and resistance-free inside. The pump of the the ballast tank was tested in the bathroom sink to test if water could successfully be pumped in and out. The pump did work successfully when tested five times.

A picture of the tubing and pliers we used to get the proper length is show below.

Part 1: Testing the Pump

 

Part 2: Testing the Pump


Our next step is to fully compile the parts of the submersible together and complete its construction. After its completion, we will repeatedly test its functionality in the pool available at the Drexel Athletic Center. If problems arise from there, we will have to formulate the best approach to fix any problems within the remaining time.

Week 6 - Updates

Our group decided to withdraw the Arduino and depth sensor aspect of the project. After some serious thought, it was decided that there would not be enough time to successfully implement the component into the overall system. By the time the Arduino boards would arrive, only a few days would be left to learn basic programming and write the code needed to log the data from the depth sensor. This would leave no extra time for troubleshooting or adjustments. Instead of rushing through this aspect of the project haphazardly, the group decided that it was best to eliminate this aspect of the project. As a result, the abandonment of the Arduino and depth sensor components allows us to focus more time on the ballast tank system.

The rest of the project is moving as scheduled. The parts are being compiled and put together. Videos and pictures will be uploaded shortly, showing its progress.

Week 5 - Updates

Unfortunately, due to unforeseeable circumstances, our group did not make as much progress as hoped.

However, the small progress that was made included the delivery of parts and new information. The solenoid valve and other parts of the ballast tank was shipped in early this week and the depth sensor arrived shortly after as well. The other vital part still needed is an Arduino board. The group was hoping to secure one from by checking it out of one of Drexel's Engineering labs. However, after talking to the advisor in charge, we found out that if we decided to carry on with this aspect of the project, we would have to spend more of our funds to order one.

After a quick trip to the machine shop, the ballast system can now be assembled. A 1/2" clear tubing will be used to connect the pump valve and ballast tank. The ballast tank will be a PVC pipe with a barbed hose connection on the bottom so that it can easily be connected it to the rest of the system.

Week 4 - Updates (Testing and Ordering)

 On Saturday, Group 004-07 went to the Franklin Institute Science Festival to exhibit their basic submersible and help out at Drexel's SeaPerch booth. To prepare for this event, a basic working model of the submersible had to be completed.

The pictures below are of us in the process of constructing the submersible.

Unfortunately, the "basic" model was not as easy to finish as expected. We ran in to a couple of difficulties. One of our motors wasn't functioning and as a result could not power one of the propellers needed to make the submersible fully run. After using a multimeter on the board, we realized that it was not the motor that wasn't functioning correctly, it was the switch that was causing all of the difficulties. To solve this issue, we had to unsodder the old switch from the board and sodder the new one back on. This step also gave us some difficulty because melting the sodder off the board to release the old switch was not easy to do. To fix this, we were able to find a sodder vacuum which essentially sucks the melted sodder off the board once the heat of the soddering iron melts it to a certain extent. This worked successfully so that the new switch could be successfully secured on the board. With the new switch in place, all motors were working successfully and powered each of the three propellers.

We chose not to permanently secure the PVC pipes with glue or adhere the motors in place on the PVC pipes because we felt that they might not be where we would want them for our future modifications. For example, the third motor is not actually needed in our final model because the ballast tank will be used to control the depth.

On the day of the event, our group attended the fair from 9 AM to 2 PM. It was a good learning experience because there were SeaPerch professional there to advise us and give us pointers. We tested out our submersible in the water for the first time. From the first test run, we could see that our submersible would need to be ballasted (weighted) to function correctly. The Sea Perch volunteers there were able to tell us that we could slit the cylindrical foam floats to make it easier for us to try out different float sizes on our submersible. This was helpful because then we did not have to take apart our submersible each time we tried to figure out the best ballast weight system for our submersible. Another issue we noticed was our design. We chose to veer off the original design proposed by the SeaPerch kit to better accommodate the ballast tank system design used in our future modification. The resulting design was much wider and a somewhat inverted compared to the original design. We noticed that the weight of our new design was not proportioned in the same way and as a result the weight of one side was heavier than the other making it extremely hard to ballast the submersible in the standard SeaPerch way. From this information, we realized that we were going to have to set aside more time to ballasting the submersible as it was not easy t get right and because it was vital to the effectiveness of the design. We also realized that thought it was important for us to realize how hard it was to ballast the submersible correctly, we did not want to waste time ballasting the basic version of our submersible now because it would require different ballasting once our modifications were put in place.

The Sea Perch booth at the Franklin Institute was also interesting to see. There was a mock set up of the actual competition Sea Perch hosts so that students can test their submersibles against each other by maneuvering their robots through an obstacle of hoops at various heights. This was engaging to see because we were able to see what Sea Perch was originally about and how we were going to change it to make improvements.

There is a picture of our group, below, in front of the fire truck that filled up the Sea Perch pool that kids could use to try out the underwater submersibles. 

Later on this week, we ordered parts for the ballast system and will be waiting for those parts to arrive. Shortly after, we went to the machine shop to see if we could find any of the other parts we needed lying around. We found a large PVC pipe that could be used as a tank if we get an endcap to secure an end. As for the arduino and depth sensor, once we talked to the advisor in charge of the arduino based engineering projects, he advised us to look in to Open Log which can be found using the following link: http://www.sparkfun.com/products/9530. Open Log would be used to help us log the data. However, it has not been ordered yet because we are trying to figure out if it can be done without Open Log to save money.

Week 2 Building the SeaPerch

A Sea Perch "Remotely Operated Vehicle" or "ROV" Kit was given to create a basic structure from which various modifications could be added to increase its efficiency.


 The parts included in the Sea Perch "ROV" kit are listed in the table below.

Table 1- Materials in the Sea Pearch

Quantity	Description
1	Mesh  - 12” x 8” – Black Polyethylene
1	Sealed Lead Acid Battery – 12V
1	Sealed Lead Acid Battery Charger – 12 V, 500 mA
1	Wax Bowl Ring
10	White PVC ½” – 90 degree Elbow
6	White PVC ½” x 12” – Straight Pipe
6	Tie Wraps – Motor Mount – 11 – ¼” - Blue
1	Electrical Tape – Black - Roll
4	White PVC ½” - Tee
1	SeaSwitch Control Box Kit
2	Pool Noodle – 5” Piece
1	50 ft. 350 Mhz Cat 5e Stranded Cable W/RJ-45
1	Velcro Cable Tie
3	Film Cannister – 35
1	18 Awg Speaker Wire – 6’
1	Battery Charger Cable – SLA Cord
3	12 VDC Motor, o.7 A – Shaft Diameter “0.091”
15	Cable/Zip Ties – 6” Black
1	Transfer Pipette – Disposable
1	Black Sharpie Marker
1	Sea Perch Pen
1	Solder – 60/40 Rosin Core
3	Propellers – Plastic 1/8” Shaft Size
3	Propeller Shaft Threaded Coupler
2	Alligator Clips
1	Black Alligator Clip Insulator
1	Red Alligator Clip Insulator
1	Urethane Adhesive & Mixing Stick 3.5 Gram
1	Butyl Rubber Tape – 1.5” x 3”
1	Alcohol Wipe
3	Threaded Insert Tee Nut
3	Nylon-Insert Hex Locknut 4-40 – Stainless Steel
1	4-40 x 3/8” Pan Head Machine Screw
1	Safety Glasses

A building manual regarding the Sea Perch "ROV" Kit was found on the Sea Perch website using the link found below.


http://seaperch.mit.edu/docs/seaperch-build-october2011.pdf

Tasks Completed

1) PVC Pipes cut into modified predetermined lengths (Refer to Table B Below)
2) Required holes drilled in to PVC pipes at predetermined locations
3) Sealed motors so that wax cannot enter
4) Waterproofed the motors with wax

Above is a picture of all of the cut PVC pipes with the required holes.

Table B - Frame Assembly Original and Modified Measurements

Number of PVC Pipes	Original Measurement (inches)	Modified Measurement (inches)
2	4	9.5
2	6.5	12
4	1.5	1.5
4	5	5
2	2.5	2.5
2	4.5