Tracker Cases

Along with programming the tracking units that each of us “polar bears” is carrying, the classrooms built attachment cases. If you were putting a tracking device on a polar bear, how would you attach it so that it was protected and did not interfere with the bears behavior?
Tracker units have to stay on even when the polar bears are fighting!

The cases should be sturdy. Polar bears prey on seals that weigh several hundred pounds, and may even have to fight with other bears, so the case has to shield the tracker from impacts.

The cases should protect against low temperatures. The trackers run on batteries, and in the cold polar temperatures batteries tend to discharge very quickly, so the case has to help keep the tracker warm.

The cases should be waterproof. Polar bears swim, and if the trackers are to keep functioning, they have to stay dry.
The PVC case is sturdy, warm and waterproof

The tracking units should be inconspicuous, but at the same time be recognizable. If an animal has an obvious tracker, other animals may treat it differently. But, it also helps if we can visually recognize tagged animals. Balancing these two conflicting requirements is tough!

The cases should be lightweight and streamlined. If the case is too heavy or too uncomfortable, it will interfere with the competitive ability of the bear to fight or get food.
The waist case is inconspicuous and streamlined

The cases should be easy to attach but also securely attached. To minimize stress to the animals, we want to minimize the time we need to handle them, so a quick attachment method is important. But then, we also don’t want the trackers to fall off, so they need to stay attached!
The pouch case is pretty easy to attach

Since the trackers run on batteries, we need to charge them up once in a while. Again to minimize impact on the animals, it needs to be quick and easy to service the trackers.
The plastic case is easy to charge and attach

We want to keep the cost of each case as low as possible, because if we have a fixed amount of money, we can buy more of the inexpensive ones – as long as they are fully functional in all other respects.
The arm case is inexpensive

Each of the classes engineered excellent solutions to all these requirements. Each one was different, and let’s see how they solved all the different challenges!


Polar bear SK wearing the waist case

The arm case was inexpensive, and fairly inconspicuous and easy to charge. However, it wasn’t very waterproof.
The waist case was all white and very inconspicuous, and very streamlined. But it was also hard to see, and hard to attach, we kept getting the large hook and loop stuck in our fur!
The pouch was pretty good at a lot of requirements, it was moderately sturdy, waterproof, lightweight, streamlined and securely attached. However, it didn’t provide much temperature protection, and it was expensive.
The plastic snap case was very easy to charge and easy to attach, but it wasn’t very sturdy.
The PVC case was very sturdy and waterproof, and because it was black and well insulated offered good temperature protection. However, because it was black it was also conspicuous against our white fur, and was heavy/bulky which meant it was difficult to attach securely. The screw top that made it perfectly waterproof also made it harder to charge the batteries.
Polar Bear MH does not like his tracker case

Overall, the plastic snap case rated the best, followed by the waist band, the arm band, and the pouch. The PVC case was the most interesting, as it was the very best in several categories, but also the worst in several, as a result of tradeoffs between conflicting requirements! This just goes to show how challenging – and rewarding – engineering can be. What would you add or change in the design of your next case?
Polar bear DS wearing the best overall case

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