Tuesday, July 29, 2008

Evaluation 3.2


I think that my prototype box went relatively well. During the process I needed quite a lot of help and guidance but I finished it on time, it works, and the outside appearance is pretty good.

To begin with I had no problems. We started the prototype in week 2 of term 2 when we were given the solar garden light to pull apart. The solar panel, circuit and battery were the parts that we needed. Once this was done we were given the top plate of the box. I sanded it and filed it down. I then scribed, measured, and drilled out the holes for the LED’s and the wires of the solar panel. I bent the box into box shape. Then cut out the brackets, scribed, drilled and bent them. I learnt that next time I need to push the drill through slower so that it doesn’t get stuck.

When I was drilling the holes for the rivets they kept slipping so a lot of the rivets went on wonky. But that is a very small issue. The actual putting in of the rivets was difficult too as I wasn’t strong enough to use the rivet gun but that is not a fault of the design and as I won’t be using rivets in my final design it doesn’t matter at all.

I sanded, with 220, and filed the bottom plate, bent it and drilled the holes in the side for the screw. After I screwed the bottom plate on I got out the circuit from the solar light. I detached and de-soldered the wires leading to the solar panel, the battery, and the LED. The board was very small so when I was de-soldering the solder sometimes escaped to other parts of the board, making it hard for me to get it off. If the circuit I use for my final design is that small I will be more careful when using the solder sucker to ensure this doesn’t happen again.

I attached the first set of wires onto the circuit fine but when it came to attaching wires and LED’s to these wires I had a bit of trouble. To attach these wires to each other they had to be wound around one another and then soldered. I would wind one around but before I could solder it had detached itself again. In my final design I will use metal crocodile clip holder so that I don’t have to try and hold it together and solder it at the same time. Because that didn’t work.

A major problem I had throughout the whole of the last half of the process of making the prototype box was that the wires kept breaking off. The joins to the board and the other pieces of wire were not strong enough no matter how well, or how many times, I soldered them. I’m not sure if this was a problem with my soldering, the strength of the wires, or just me not being careful enough. So in my final design I will solder and handle my circuit with more care. If they still break I could use stronger wire.

When the circuit was finished I had another problem with things snapping off. The hot glue was not really the best thing to hold the LED’s to the top of the box. It took three tries to get them to stick and even then they are not the most stable things ever. The glue seemed to work fine sticking the battery snap and circuit board to the sides of the box, but if I did it again I would use something different to hold the LED’s to the top of the box.

I probably wouldn’t change anything about the metal design because it worked well and was easy to assemble. I would attach the wires closer to the board as the way they are is very flimsy, if I were to change the circuit. Because of them being flimsy they come loose and stop the circuit from working. But in my final design I think the wires will be further away from my circuit board anyway, so it doesn’t make any difference.

At the end of it all I think it went pretty well. Although there were quite a few things I would change if I did it again, it was a first try and it does what its supposed to do without too much hassle to get there. In my final design I will watch my soldering and de-soldering, handle the circuit more carefully and (if I need to) use a different kind of glue.

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