For runs of maybe 5-10+ boards, SLS 3D printing is pretty competitive because you can design everything to fit exactly. The setup cost tends to be high (minimum

For runs of maybe 5-10+ boards, SLS 3D printing is pretty competitive because you can design everything to fit exactly. The setup cost tends to be high (minimum order of £40/$50), but individually a small printed enclosure will cost the same or less than a box from Hammond or the like. Certainly compared to the cost of customising a name-brand enclosure (short run), it's a no brainer, and you can add awkward structural elements that simply aren't possible even with CNC machining. Once you get a bit bigger (physical volume), the cost becomes prohibitive and you can look at etruded aluminium. If you're clever you can design a PCB to act as end panels. 3D printing is also a nice stepping stone before getting a machined enclosure made - saves a lot of cash if you find you've missed something. And yes - too easy to forget things like standoff holes, or where a connector is going to be mounted. I suspect because it's annoying having to double your board area so you can fit an M3 clearance hole/keepout. Cheaper to not bother. If you go with 3D printing you can do things like add slots and slide your board in.