Today was meant to be a day spent on the electromagnet. That got put to one side though. Again, I tried to solder to the copper wires and again the solder resolutely refused to stick. I'm guessing it's a lead-free solder which would account for its uselessness on this occasion.
Needless to say, I experimented with my existing 5 coils and the results though not spectacular showed improvement. I must admit that I'm viewing other solutions at the moment. This is just taking far too long!
Meanwhile, yesterday, in Walmart I found a $6 fan that runs off two D cells. I bought one and tried it off my solar panel. Nothing happened which really didn't surprise me in the slightest. Regular readers will recall my disdain for all this green garbage on account of how poorly it works. A few minutes with a screwdriver and my angle grinder reduced the really quite formidable plastic to something manageable.
Actually, it shifts so much air that if this survives testing then I'll replace my two undersized CPU fans with a pair of these. This fan has three advantages. First it can be used in reverse. Second, it's more powerful and thirdly since it runs off a pair of D cells, there's no reason it should not run equally well off a 10,000mah 3.7v lithium battery as sold in Walmart for $12. I could have each fan individually powered by these and have a stack ready charged.
In other news, I looked at the front door and discovered the problem with looseness is due to either a worn out nylon bushing or the bushing and the track it slides it. Today I emailed All Points Bus Parts who advertise these bushes but don't actually seem to have prices on them.
I've been giving thought to power and I'm pretty much in favor of having no 12v battery. My lighting should work well off D cells or even AA or AAA cells since those throwaway LED lighting units abound and are cheap enough. Lithium cells are an interesting idea but I can get the same capacity in a far safer NiMh D cell.
At the end of the day, all I want to power are 2 - 4 fans, my phone and possibly a tablet. I'm not in the slightest interested in televisions or fridges or the vast majority of the modern electronic junk. I like my little piece of silence.
As an afterthought, I looked at the fan and realized I needed a spacer. Immediately plywood came to mind but when I was looking at my off cuts in the shed (I always keep my off cuts) when I saw I still had off cuts from the vinyl planks that I used for the bathroom floor. Thinking about how to cut them I remembered my circle cutting tool. Setting one side of my cutter differently from the other enabled me to cut two very nice looking rings. I'd have liked to make them wider but my tool wouldn't cut wider.
I think this fan is probably better than the CPU fans I bought. My electrical test was a failure because the already weakened batteries died after a couple of hours. Having said that, I'll install one fan and will test it tomorrow. It should shift a lot more air than my CPU fans. And for the curious, here's the fan box.