Week of 2/20/12

This week was aimed at waterproofing the servomotor to be used in the marker dropper mechanism as well as waterproofing the kill switch. We had two non working servos at our disposal to conduct waterproofing tests on so we tested a combination of methods on each. The servos are waterproof but only to a certain extent. Full submersion to the depths that are required for the competition are not plausible for the servo alone. We took the servos apart and filled the electronics section with a high viscosity mineral oil. We then filled the front gear reduction compartment with a silicon grease. The servo was then reassembled with an O-ring around the output shaft with added silicon grease. Screwing on the servo horn allowed for the O-ring to compress and form a water tight seal. The exterior was then cleaned and all of the seems were touched up with duco cement and the wires extruding out the rear of the servo were coated with plasti dip. The kill switch followed a similar method of waterproofing. The wires and terminals were dipped in plasti dip and the front seems were touched up with duco cement. The duco cement provides a clear barrier to inhibit water from entering. The kill switch was then mounted to a mounting plate with a rubber boot recovered from last years group to protect the front of the switch from water entry.

Week of 2/13/12

This week was devoted to the grasp/release mechanism. We have held off on this component due to it being a subsystem that did not prevent the vehicle from progressing to the final stages. We purchased two double acting air cylinders for the initial design, recently this has changed to only utilizing one double acting air cylinder. After redesigning the grasp release mechanism with a different geometry for the claws and knowing the displacement of the air cylinder to be two inches. It was deemed that the width of the mechanism would have to be too great to allow for proper rotation about the pivot point. The dimensions would not physically work and the air cylinder would prematurely halt created unnecessary stress on the mechanism. The conclusion was to see if we can return the two previously purchased air cylinders and utilize an air cylinder with only one inch of displacement. 

Week of 2/6/12

The majority of the beginning of this week was spent on the presentation. The seacon connectors finally came in towards the end of the week so we spent much time prepping wires for soldering. The thrusters were removed from the vehicle where we then removed the previous internal wires and inserted the new wires that were supplied with the seacon connectors. We then soldered and shrink wrapped the four remaining thrusters since the two new thrusters came pre-potted. After soldering the thrusters need to be potted with epoxy before they are completed and watertight. The upcoming week will focus more on finishing and installing all the seacon connectors with the exterior components.

Week of 1/30/12

This week we finished assembling the compressed air system and integrated it with the torpedo launcher. We had difficulties at first with attaching the low pressure regulator to the high pressure regulator. The sealing of the two together created some losses of the compressed air. After learning the proper order of operation for the compressed air system we fired both torpedo launchers which proved to be a success. The torpedo fired around 6-8ft @ 100psi. This was in the lab and future test underwater will be required to fine tune the system. The torpedo flew straight as expected so the test passed. The learning from these test was necessary and meanwhile we consumed majority of the compressed gas in the bottle. Future tests will require the bottle to be refilled.

Week of 1/23/12

Throughout the week, the areas of focus were on getting the camera enclosures to pass the water tightness test and to finish the compressed air system. Many of the compressed air parts were not received until late Friday so completion and testing will have to be pushed til the following week. The camera enclosures had slight leaking issues last week so additional coats of silicon were required along the seems of the acrylic. It seemed that majority of the water was entering through the screw holes on the mounting surfaces of the enclosures. This  proves that the sealing washers are not performing as intended. An additional idea was proposed to add a rubber layer along the bottom of the camera enclosures. By doing this the rubber provided an additional layer to stop water entering and the screw holes were filled with epoxy. This extra addition worked for stopping water, but aesthetically the enclosures are not very appealing. Ryan can now use them for his computer vision testing. After a discussion today with Eric, concerns about the enclosures at 16ft depth and the overall durability of the boxes is now possibly leading to a different design for the enclosures. More on the design change to come in the next week or two. Friday afternoon was dedicated to measuring and hand drawing sketches of each part to be added/changed in the Pro/E model.By hand drawing and measuring before modeling in Pro/E allows for faster production of the parts in the CAD program. Accurate measurements and material assigning in Pro/E are vital for future and final density and weight values.

Water tight testing week of 1/16/12

This week we aimed to finish the camera enclosures and do a water tight test on them as well as the hull. We tested the vehicle at Morcom Aquatic Center and determined the hull had a small amount of water entering. The camera enclosures both had water entering through edge cracks as well as the screw locations where the sealing washers are supposed to seal off water entrance. A slight change will be required to complete the water tightness test.