Photo accessories in self-build
If you are in a position - technically as well as by machine - to produce things of photo equipment itself, which is always a round thing. Alone is the price advantage. It is often much cheaper than buying them new. Moreover, there is also the advantage of being able to adjust the parts completely and according to size for each camera, accurately and precisely. Often I find that my solutions are sometimes better than industrially manufactured products.
Once I learned the profession as a mechanic and then come to me little crafts for my photography hobby just right. My first major object is a tall tripod. Other projects I have in work, but I am still far in the early stages.