I am currently writing this after drinking a chamomile tea (or as I know it in spanish, te de manzanilla) and then had dinner. That time was well spent organizing my thoughts.
Today marks the day where almost all of my current worries and anxieties end, or rather, the ones which were caused by my current semester’s exam and project season. Despite it not being december we’ve already finished Ms. Castro’s statics course and it seems like I’ve aced it completely. Also, my group for our manufacturing processes finally gathered to make our semester’s project: a smelting furnace!
First let me talk about my statics course: Last wednesday was when we took our leveling exams1 and Ms. Castro gave us three hours to finish all the exams we owed. For people like me who only failed one unit? That was great! As for others who failed all of their exams? Yeah 3 hours was a tight deadline.
Still, I was stressed the days before AND during the exam; The exam I owed was the first unit’s exam, which was about breaking down forces both in a plane and in 3D space, and needed to pass at least two excersises and have the 3D problem solved correctly, otherwise one and half notebooks full excersises done in two months went to waste. Castro also gave us the option to do more excersises than the ones initially presented in the exam to aid in our grade, which was a true blessing since one of the problems she gave us (obtaining the tension between two cables) gave a negative tension for one them.
Mind you, a cable is only supposed to pull from the node it is attached from to the where it is tied. Therefore under normal conditions a cable’s tension is positive; if it isn’t then it means that a rope is somehow pushing to its attachment point. That is cientifically impossible.
I was surprised to see a negative tension as the correct answer to the problem; I tried to see if I had made an error, but no, the only way to balance a force of 960lb pushing down on a node attached to two cables on a wall is to have the upper cable pulling the node, then have the other node push on that node as to balance the massive horizontal force made by the previous cable. Thankfully the two-correct-problem policy came in handy, as when I went to deliver my exam I asked for two more excersises and I chose the two easiest excersises ever. Just find the components of three forces.
Ms. Castro still hasn’t delivered our final grades, but I know I did well on that exam, so now I only have to wait.
As for the smelting furnace, its a project that is going to be the determinant of our grades regarding that course. You see, originally we were going to do presentations about the theorical knowledge of the units, but the first team flunked the first slides so hard that our teacher got angry at all of us. Therefore slide shows were cancelled.
Not really, we still need to do them but we won’t have to do the presentation for them
As a replacement for our grading, our teacher Mr. Miranda gave us an alternative: make a smelting furnace and pour aluminium into molds. The problem now was the process of making said furnace.
Initially my team wanted to do a carbon furnace but it got taken by another team before we could react. So our other option was to make an induction furnace; that was a horrible mistake.
As it turns to make an induction you need the copper coil, the cooling for it, and a battery to attach the coil to. To make long story short, it’s basically impossible for a group of rag-tag students to find those things on a scale for a furnace of 30cm in diameter.
- First of all where do you find the copper coil? You could find a copper tube but how do you bend it to a coil?
- How do you cool the coil? If the coil is hollow then you can get away with not having a cooling system but then you run in to the previous problem.
- What’s the power source you’re going to use? A car battery at least, but then you run in to induction heating.
Yeah the induction oven wasn’t going to work.
Thankfully our teacher guided us into making a coal furnace, which is much simpler: just a big concrete bucket with a hole on its side. After a month of gathering materials we gathered in my house and started working.
I was in charge of buying the concrete powder and sand needed to make the concrete, so I bought 6kg of powder (foreshadowing) and a sack of sand and called it a day. A clasmate brought a cut barrel of 40cm in diameter while another brought some tools, and then we went walked to the supermarket and buy a plastic bucked of the correct size for the inner side of the furnace.
The rest of my teammates came and so we made our concrete mix, and fun fact! You cannot fill a 40cm cut barrel with only 6kg of concrete. Panic ensues.
We quickly recycled a spare iron wire I had laying around and spread it around the diameter of the barrel so we can pour more concrete later, then we went to the hardware nearby to buy more powde- oh. It’s closed.
After discussing what to do one my teammates asked his father to purchase more concrete from another hardware store and bring it to us. And so we had to wait. We ordered some pizza and enjoyed our break.
Back to work we discovered that we ran out of sand, so we had to improvise. First we poured gravel and other pieces of concrete laying around in to the bottom of the barrel so it makes space the concrete doesn’t have to occupy, then we used unclean dirt as our replacement for sand. That wasn’t probably our best idea, but we were desperate.
And thus the first part of our project was done. Now we have to wait for it to dry, remove the inner bucket and we should be ready to smelt some metal.
I still need to do some stuff, but its a start.
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A leveling exam, or as it is known in spanish exámen de nivelación or exámen de segunda oportunidad, is a system in my university where if you fail an exam, you can do it again either some days later or at the end of course so you don’t fail the entire course. I don’t know how its handled in other unis but this is how it’s done here. ↩︎