Week Eight C

Following testing, we decided that some changes needed to be made to the SeaPerch. The string attachment wasn't very stable, the hot glue resulted in a crooked and falling apart frame, the wire from the depth sensor was getting in the way of the propellers, the attachment of the extra motor was shaky, and the floatation rings were sliding back and forth. The changes made helped to make the submersible more stable and sturdy. Everything is now intact. The submersible can easily be transported between locations as well as it can be taken in and out of the water with fewer mishaps.

The following pictures illustrate the changes that were made to the submersible:

New way of attaching fishing line to the syringe plunger

Another syringe that has been outfitted for our submersible

Closeup of the winding mechanism

Hot glue wasn't holding the SeaPerch together snugly, so we
reattached the PVC with something stronger

The depth sensor wire was getting in the way, so we

taped it down and threaded it along the top of the SeaPerch.

This view of the back of the SeaPerch shows that the

wires now are kept out of the way of the propellers.

The attachment of the extra motor was shaky, so we re-soldered the wires

together and tucked them a safe distance away from the propellers.

Hot glue was used to fix the foam pieces evenly across the beams.

Week Eight B

Last Thursday, we took our perch to the pool! At the pool, we made sure everything worked under the water. The propellers spun properly, propelling the submersible through the water. The submersible had a little trouble fighting the waves produced by the lap swimmers. Because we plan on using the submersible to collect water samples from the river, waves shouldn't be a problem. If the submersible were to be used in a body of water with strong waves and/or currents, larger propeller and perhaps a stronger motor may have to be used.

While at the pool, we figured out how much of the Styrofoam noodle we needed to balance our SeaPerch. We cut the foam down until the ratio of floatation resulted in the SeaPerch being sufficiently buoyant. We also utilized the depth sensor. While in the 4.5 foot zone the depth sensor read 3.4 feet. This makes sense because the frame of the perch and the distance the sensor hung down was about this difference.

The SeaPerch successfully took two samples of water. After taking the first sample of water, the mechanism was reset and tried again. The video below is from the second trial. Several problems were noted during testing. First of all, the wires often got in the way of the propellers. This problem was fixed temporarily with zip ties. The SeaPerch was slightly unstable and the hot glue did not hold up. The PVC pieces came apart and had to be pushed back together. The floatation rings slid around and fell off if the PVC pipes separated. The motor that pulled the syringe plunger was slightly wobbly and needed to be better secured. These problems will be addressed.

Below are a few pictures and a video from testing. For more pictures, see the page to the right titled "Pool Testing Photo Album".

Chris, Ben, and Andy man the switches, battery, and depth sensors

Rod swims with the SeaPerch

The water sampling device

                                            

The depth sensor at work

Underwater video of the submersible taking a water sample!

Week Eight A

The week began with creating a better string mechanism for pulling out the syringe plunger. Originally, the fishing line was just wound around the post of a spinning motor. Ben drilled a hole in a metal piece that makes the attachment of the fishing line to the motor more smooth and finished. We also worked on the control box, switches, and motor; trying to determine the best method of utilizing the battery to power both the propeller motors and the string attachment motor.

Ben drilled a hole for fishing line

Ben attaches new piece to motor

Pete solders the power cord into splits