We were wandering through the Royal Ontario Museum gift shop, and saw the 4M Green Science Dynamo Torch. It wasn't too expensive, and our 8 year old wanted to check it out, so why not? We managed to get it assembled and working, which is more than I was expecting, really. It is a chance for kids to have at least some hands-on experience with wires, motors, and gears. Here are a few photos of the process and a bit of a review
All the parts are reasonably thick plastic, with a metal motor/generator, some metal screws, and an LED lightbulb.
The instructions were clear enough, with a good exploded-view diagram and numbered steps. I'm not sure if our eight-year-old could have got it working on her own, but almost.
While this is obviously a toy, the pieces fit together quite well, and in particular the gears meshed together well.
Each step of the way we could see how things were working, and the next step was pretty obvious.
Finally everything was together - we didn't rush through it, and it took about half an hour. There is no soldering involved, and no risk of a shock. No glue or paint to make a mess, either. The screws and a metal pin for the gears are quite small and could easily be lost, but other than that, it was perfect for even an eight year old.
Best of all, it worked the first try! As long as you make sure the wires are tied pretty tightly to the motor, not much else can go wrong. It provides quite a bright green light when you're cranking it, but there is no capacitor, so as soon as you stop, it goes dark.
Overall I'd recommend it - not too complicated or involved, but it worked as expected. The instructions include a 'Fun Facts' section that does a pretty good job of describing how an electric motor, and a generator work, but running around with the flashlight was more fun than reading the description!
(I took a look at the 4M Website to find a link to add here, but it was slow, hard to search, and when I finally found the details, there's no way to link directly to them.)