Obviously the sheet metal needs holes in it for bolts. The sheet aluminium will be either CNC laser cut or CNC water jet cut.
I’ve got three options:
Add holes to my design at the exact dimensions that I need them to be. I am placing myself at the mercy of the accuracy of the CNC cutter to ensure I have no slop which might let the bolts move. But no drilling!
Leave the holes out of the design. I measure the cut patterns to find the right places for the holes and drill them myself. Using a drill will give me a clean hole that I can fully trust the dimensions of. This is what I’ve done in the past, but I haven’t been accurate enough with my placement.
Undersize the holes in my design, and drill them out to the correct size later. I don’t have to measure anything, but still get a clean accurate drill hole.
Any practical advice from someone who’s done this before?