Summary This replaces the top plastic/acrylic piece on the lid for a FlashForge Creator Pro and provides an opening with rest points for a 120mm PC fan. This is part of my ventilation system to vent the ABS fumes to an open window or external vent. I designed it so the fan sits on to rather than mounting it with screws so you don't have to attach the lid to your ducting system. I have also added a version that has the holes all the way through should you choose to mount the fan to the top. The holes are sized for 8-32 hardware. I was concerned about the strength of this when I started the design since you are taking an already flimsy top cover and cutting it into two pieces. It actually worked out well and I find that, because of the added thickness, this ends up being more sturdy than the original top. The 120mm fan to dryer duct adapter used in the picture is: http://www.thingiverse.com/thing:1163183 Print Settings Printer: FlashForge Creator Pro Rafts: No Supports: No Resolution: .20 is fine Infill: 20% Notes: Simple print.