So, didn’t do posts inbetween from #9 till now since i was lazy and it seemed that not much philosophical depths the hand skills training carried out in the previous classes could be written about unless backed by enough photographs and illustrations which would have called for extreme dedication on my part. So a summary rather:
- In electronics, we began experimenting with LEDs and how to wire them up in the correct way and in the not correct ways. We saw, willing or otherwise how LEDs can be damaged if a resistor is not used. Interestingly we have some LEDs in our stock which has some form of inbuilt circuitry that A) prevents them from blowing up even without a resistor (though it gets hot) B) Red, green and blue colors in single LED in sequence (else it would have been a white LED) and C) The colors switch automatically as if programmed in that way.
- Next all kids were asked to recreate the first alphabets of their names on a breadboard, learning in the process the breadboard basics. But this was the first time the question was posed: how to connect a bunch of LEDs to one another but lit by a single battery?
- Series and parallel connections were tried out as experiments and it was concluded that in series connections, there’s a limit as to how many LEDs can be lit up. If connected in series, meaning positive leg of first LED to the positive of a 9V battery and the negative leg connected to the positive leg of another LED, this kind of connection was first tested out. Suppose all LEDs were of red type, each LED drops 1.5V by default. So how many would fit in to cover 9V? So, 1.5V times 6 = 9 that means at the max 6 LEDs could be lit up in series!
- However, in a parallel connection all positive legs are joined together and connected to a 9V battery via a resistor while all the negative legs are joined together to meet the negative of the battery. Even if each LED drops 1.5V, since its in parallel the 1.5V across all remains the same irrespective of how many LEDs are connected. Its a bit abstract or maybe i am not taking effort to explain well, either ways its better than series connection. This was established experimentally.
- Next, the kids were asked to construct their alphabets on a zero PCB. This involved learning a bit about the soldering gun, how to join the legs together, put jumpers across when continuous path construction using solder itself as molten wire was not possible, etc. This took some time because this is really a kind of skill. After many faithfully constructed their letters, some lit up, some didnt and it was kind of bitter sweet experience. But due to lack of time we move ahead.
- The idea of Arduino as a small programmable computer was introduced. Initally the LED on board was played with. Then it was time to connect an external LED and do the blinking and fading examples. The fading code was explained and kids played with the timings. The next test was to use fading on the alphabets kids had made, which worked quiet easily!
- While the above session dealt with Arduino’s output capability, in another session the idea of analog signals and its measurement was discussed. Due to my own ill-planning i made a huge mess as to how to deliver this sligthly abstract but very important concept across. It was a mess and the kids were bewildered unnecessarily because i asked them to simulate different voltages using voltage dividers and so on with some formulas and stuff. Totally un-called for. I rather could have arranged for some analog sensors like LDRs and stuff to illustrate analog measurements!
Now we come to 3d printing.
The obvious questions that one would ask in general:
- Why make something in the first place?
- What are the ways of making things?
- If we have all the ways of making things then why invent more? What situations make conventional making techniques obsolete or difficult?
- What is 3d printing and how it works?
- When did it all began and how is it relevant today?
The above questions in themselves need 1 session or atleast half of it. But we dont have that luxuary as we need to begin on the projects as soon as possible. So i will skip all that and do the following:
- What is 3D printing?
- Make a shape on tinkerCAD online.
- Export it to Cura for slicing
- See the wonder while it gets printed.
So first to set the context of making, what are the conventional ways?
- Joining, using existing shapes and getting them together through gluing or welding, etc.
- Subtractive processes such as sculpting, turning, milling, etc.
- Additive processes such as brick laying, 3d printing, etc.
- Moulding and casting, such as all engines, etc.
So we could illustrate 3d printing by an actual look at how the layers are formed line by line. I think that should be enough to replace any words from anyone.
The remaining is plain discovery mode with some assistance and letting things evolve.