I always liked the new UDOO X86 case design because I knew I could either stack multiple case bottoms; or simply replace the risers to provide space for a 2.5” SATA HDD under the mainboard. Actually all I did was replace the 4 x 12mm corner risers that come with the case with 25mm long nylon pieces. See attached photos. It should be noted that all the flat head screws and spacers used are M3 threaded; and there are already 4 additional holes on the UDOO X86 case bottom to mount a standard 2.5” drive. Note 1: I used 3 x 3mm long M3 screws, 2 x M3 washers, and a 6mm spacer to mount the two M.2 devices; 4 x 8mm long M3 screws with M3 nut spacers to mount the SATA drive to the base; and 6mm long M3 screws and M3 nuts for everything else. Note 2: You can barely see where I attached the 2 antennas along the side (white wire) and rear (black wire) edges of the case bottom with the foil pointing inward. Note 3: I installed Win10 version 1703 on a SATA HDD and Ubuntu 16.04.2 on a 32GB M.2 SSD.