At the state competition, we totally weren't prepared to make a scale, lacking some very important pieces (water). I scrambled through the box to find some way to make a decent scale. I ended up making it using a bunch of tubes/water bottles. (see the
images) This got us 11th place (we had no time to test/calibrate it). Tier 3 because it tipped over and I had to touch it to pick it back up... and the estimated mass was about 30g off of the actual mass.
Now that I reflect back on the situation, I think, with the limitations we faced, we did a great job. Sure it was our fault and stuff for not being prepared, but being able to take a box of random junk and making a scale out of it on the spot, when other teams knew exactly what they were doing, we didn't do too bad.
I really like the idea of the event sup providing a box load of materials (same for everyone) and having them do a certain task with them. The task or possible tasks should be explained in the rules so the students can actually try to do something for the event instead of just walking blindly into it. This would require some creativity from the judges however because they would have to choose the materials that would make it possible in multiple ways to complete the certain task.
Some down sides to the idea are that you can't really prepare for something like this. I thought the same thing for JYC this year but figured out universal ways to include just about any mystery material into the device. If the judges provide the materials however, you really wouldn't be able to prepare for it and the quality of the products wouldn't be as great.
I don't know what some of the old events were about, so maybe I'm just missing something, but I'd really like to see an event where you have to really think on the spot and build something with provided materials.
EDIT: vofbassist, I think our region posted a list of possible materials, but I ignored that and tried to create a flaw in the device such that any material could fix it. For the scale at regionals, we could either put the MO along with the weight (if you take out the MO, the scale gives false readings) or, since we had a container to contain any spillage of the water, we could put the material on the bottom of the container to make it un-level. On the opposite side of the container, we used knex sticks taped together to make it level again. This way, no matter what the material was, if it was somewhat heavy, we could easily use it as an extra weight and calibrate the scale that way or if it was light, we could use it to make the device un-level.
At regionals, the MO was a CD, so I just stuck it on the side of the container and put knex sticks on the bottom to make it level again, at state, it was a chalk egg, so we used that as a mass added on to the actual object to offset the calibration if removed.