-The minimum required for the ATX tray are models Core and IO to hold the motherboard and pci cards (6 motherboard screws, or with the extensions, 9 motherboard screws).-8 total models snap-fitted and then secured with a total of 25 size M3x12mm( or similar) nuts and bolts (phillips head recommended).-Optional stand for using the tray in upright position. The motherboard and pci cards can be directly screwed onto the tray stands/holes with generic motherboard screws. The best print-result for me was to print without changing orientation and using a 0.4mm nozzle for the snap-fitting connections.The taller models have 1mm horizontal support beams to be used with tree supports and are to be cut away.-Models are max 18.2cm in length I suggest cutting out one of the pci-slot beams if its in the way of inserting a thick hmdi plug. 02-27-2026 - added 3 extra screwholes on the extensions to actually make the model ATX.02-26-2026 - v1.1 updated the models, added an optional stand.02-25-2026 - corrected io-shield height and added extra holes for nuts/bolts to the extension parts.