For a small hobby project and to learn a bit about electronics, I would like to make a DC/DC uninterruptible power supply. I really like the look of the extruded aluminum cases. However the off the shelf PCB I am looking at is smaller than the batteries. My question is are there mounting options for PCBs that are smaller than the extruded aluminum housing? If so what are they and where can I find them?
Some extruded chassis have a built-in slot to hold a PCB, but there are many other methods. If you are only building a few, there are lots of options, if you are building huge quantities, you want the cost to be as low as possible.
For a hobbyist, threaded metal or plastic spacers are my favorite. There are also unthreaded spacers, then you use a long screw and put the nut on the inside of the box.
For larger quantity manufacturing, there are also snap-in plastic spacers. If you have ever opened a tower PC, the PCB motherboard was probably attached with snap-in mounts.