The past few week’s put our efficiency to the test – and our spirit at the same time. We pulled through, worked very hard and managed to get everything working by the Final Technical Review day. That morning we uploaded the Arduino code to the Arduino board and tested out all the various parts, but faced one problem.
The GPS Shield was causing the 2 bicycle brake servo motors to go haywire. The motors just started randomly turning upon turning on the GPS Shield. Their movement was very erratic, and was very unusual. We tried pinpointing the error by checking for a short circuit somewhere, but to no avail. We then tried uploading the code without the location tracking (hence we left the GPS Shield off) and the motors worked perfectly fine.
It was rather bizarre behaviour and one we could not troubleshoot at the time. As such, for the actual review we explained that the GPS portion failed but is working without the servos being connected.
The actual review
When our turn came to share with the lecturers our progress thus far, we were more than ready to do so. We discussed everything that we did up to that point and also talked about the problems faced and our solutions to those problems. The following is a summary of feedback given by the lecturers:
- For the propeller motors, they could be spaced out more so as to allow for a wider turning angle.
- The bicycle brakes could be secured on to the pipes better, instead of using duct tape.
- The pipes were not sealed off properly as we only used the silicon sealant to do so. We should’ve used PVC glue to stick the pipes firmly together, then apply the sealant to waterproof the joints and gaps.
- We need to do detailed calculations on the vessel’s buoyancy and find out exactly how much flotation devices we need.
- We need to add a guide for the rope on the spool so as to ensure that the rope does not slip off the spool and entangle around the shaft as this would cause the motors to jam.
- We could add a liquid gasket for the water container around the acrylic opening piece so as to ensure that the container really is waterproof.
All in all, we felt that we did a good job as we got the main components working and only had to do minor adjustments to our vessel for the demo day. We would also like to express our gratitude to our lecturers for always being very critical of our work and ensuring that we learn how to fabricate things properly. While we may have quick and dirty solutions to any problem, there is always a way of fabrication that is very sound and foolproof.
After the review, we decided to seal off the pipes properly by first securing the parts together using the PVC glue, then applying the silicon sealant around the joints, as pictured below.
We applied the PVC glue on the outer ring of the pipes to be connected into the pipe connector, and applied the glue on the inside of the connectors. This allowed for even more PVC glue to be used and would make the pipe network even more rigid and firm. Next, we sealed the gaps of the pipes with the silicon sealant using a caulking gun.
Then we put it aside and let everything dry and harden, in preparation for the buoyancy test the next day.
It is very refreshing for all of us to know that the final aspects of the project are coming together nicely, and the end is very near.