New to Onshape and making 3d models, so it's pretty basic but this allowed me to put a Noctua NF-A8 FLX 80x80x25mm fan right below the motherboard, I didn't see how the other ender 3 ones could work. Holes might be a little small depending on how your mounting, i used rubber mounts they include in the box, had to drill them a hair, its a stretch but they do fit. Also i didn't see an easy spot to bolt the rear of it to, so its just the front screw and side one. My first attempt was designed upside down so I had to mirror it and reprint, the pics are of the 1st print for those wondering. Step file included for those more talented than me.