Changing times
I just received a box of childhood artifacts left behind when I left home, from high school and earlier. One was one of the hundreds of different books titled Electricity and Electronics which I had entirely forgotten, but as soon as I opened it the memories flooded back. Two things really fell into place for me from looking at one project, Making a Powerful Electromagnet.
The project required access to a lathe. When I started learning machining earlier this year, I was doing something I had wanted to do for a long time. I now vividly remember reading:
This requires that the parts which go together be turned and faced on a lathe to a mirror-like surface. For those who have the ability to perform the necessary lathe operations, and also the welding experience to weld the center core to the top plate, the magnet will open up the fascinating field of electromagnetism with many exciting experiments.
I learned MIG welding around that time in a class at the Science Museum of Minnesota (though I didn’t buy a welder until a few years ago), but my only other metalworking experience was sheet metal work in junior high school shop class. That paragraph might have been the thing that started my interest in the hobby I’ve finally taken up.
The last paragraph of the project description, however, really illustrated how times have changed.
If the magnet is to be used to lift one or more persons, it is advisable to link the top and bottom plates together with a loose piece of chain. This will prevent the bottom plate from striking the person being lifted in case a weak dry cell allows the two parts to separate.
Can you imagine that in a book written today? “Warning, never support persons…”