EldRick

Unfortunately, this has defects in the STL file that make it unprintable. Cura and Kisslicer can't print it correctly, and neither Netfabb nor any other tool I've tried will correct the errors.

The thumbscrews are 3mm diameter. You need to open up the holes with a 3mm drill, not larger, for a good fit. 3.2mm or 1/8" drill simply makes for a sloppy attachment, with wiggle in it.

I got this installed. It needs supports on at 25% to support the inside flanges, and, for my fans at least, I had to scale it up to 101% to get enough room for a light press fit on the fans. However, that said, it's the best design I've seen yet, and it even fits with the IH_HeatSink_FanDuct.stl for the rear fan, and the deflecteur_UM2.stl to better cool the PTFE spacer. And for an extra bonus, it gets rid of 12 screws and 18 grams of weight on the print head, which certainly helps speed and accuracy of printing. Excellent!

I really like the ability to see the extrusion at the tip of the nozzle - very helpful when tuning temps and speeds. Great design job!

I printed this in ABS, and tried to use it to print ABS - it browned and sagged on the left side where the plastic is close to the side of the Olssen block. I was able to use an ABS one long enough to print v2 in clear polycarbonate, at 260C. I used some adhesive aluminum duct-sealing tape to line the duct on the inside surfaces, and some Kapton tape to help hold that in place. The shiny alum should reflect some IR back at the heater block, and distribute and cool what it does absorb. Works great: I've even printed spare ducts in polycarbonate at 260C with no apparent issues - no melting, sagging, browning, or crystallization of the material.

I'm wondering if the duct wouldn't work better if it were in two pieces, with no thin flat pieces joining the right and left fan ducts? That would pretty much eliminate the parts that get overheated and tend to melt.