Velocity stack for Noctua 40mm fan NF-A4x10

cults3d

I upgraded my Monoprice Select Mini fans from cheap 30mm units to high-quality 40mm Noctua fans. I discovered a unique design for a velocity stack that I was going to print out but found the center hub cover was larger than the small 17mm motor hub on the Noctua fan. Several people had asked for a Noctua fan version, so I downloaded the STL file and used MeshMixer to resize the center hub to 17mm, then printed it out and tested it successfully. After that, I tried to post a remix but discovered the original design had a "No Derivatives" license. I left a comment on the original thing saying I had a modified version for the Noctua fan available, but there was no interest from the original designer. Recently, someone contacted me who was interested in my modified STL file, so I sent it to them, but then wondered if I could completely redesign the item from scratch using Fusion 360. I've been constantly trying to improve my skills in Fusion 360 and this looked like a great challenge. Here's what I came up with, and the results look fantastic. Since this is designed from scratch and takes inspiration from several sources, it's not a remix and thus isn't in conflict with the no derivatives license of the first one that I printed. Note that there's no math behind this design; I just used elliptical curves and measurements that looked cool. Does it actually increase airflow? No idea, but it looks great. Also, since I drew one support leg and then patterned it, I realized I could skip the pattern and have a minimal single-leg design, which again - looks great. That design has provision in the back for a 3mm pin, but I am using it with only one screw and simple friction holds it in alignment. I also printed out a twin-leg design. Obviously, the four-leg design is the most secure, but I can't imagine that four M3 bolts to hold one little 40mm fan in place are absolutely necessary. I've also included versions with a 22mm and 25mm center hub to work with fans with larger motor hubs. Only posted those in the four-arm design; contact me if you'd like a single or twin-arm design or need a different hub diameter. Including the F3D source file. In theory, this could be used to make velocity stacks for other sized fans, but I was having some issues driving the elliptical cross sections in the profiles, so no guarantees they'll behave properly. If you do remix it for a different size, please post your thing and list this as a remix; I'd love to see it!