Wow, I'd like to see a sketch of it, if you don't mind. About 3-4 years ago I also used to build different electric tools/toys, it was like a hobby to me. But a self made flashlight sounds really amazing. My grandma always used to ask me to buy her little flashlights, about every month, I couldn't understand what was she doing to them that they always got broken. But this summer I decided to find a great one for her, so here it is https://www.amazon.com/Vont-Flashlight-Flashlights-Water-resistant-Accessories/dp/B089T8HDBV. Its price is really reasonable for its quality.