30mm fan adapter for 40mm opening with nut traps

thingiverse

I was looking to install a low-profile adapter on my duct to mount a 30mm fan, but I needed it to fit a 40mm opening. This specific model comes with built-in traps to hold four M3 nuts in place and provides clearance for four M3 bolts.\r\n\r\nThe V2 upgrade improves the fitment of the nuts and bolts even further by allowing for wider openings while also creating a two-degree draft angle. As you tighten the nuts and bolts, they will naturally get gripped by the plastic more securely with each turn, reducing the likelihood of them coming loose during fan swaps.