I've previously posted accounts of my adventures building a very bright wide-angle flashing red bikelight for my daughter who rides her bike in NYC. Being highly visible is at least as important a safety measure as wearing a helmet for a cyclist in traffic in NYC. She is no engineer, but she was able to describe exactly what she wanted and couldn't find at any price.
I had to learn some new skills and enhance older ones (TIG welding of thin aluminum to thick) to "meet the spec". That was part of the fun. Perhaps it was most of the fun, and why it took me so long.
This week I shipped a finished unit. I think she likes it.