Prusa i3 mk2 - Fan Duct Improved

thingiverse

First of all, I chose the GPL license because the original Prusa i3 mk2 uses the same license. I hope that doesn't offend anyone - if it does, please contact me and we'll work it out. The orange part in the picture is the original component. I made this design based on the STL files provided by Josef Prusa and modified them just a bit. Two differences were made: The inlet side (facing the top - fan - when mounted) is about 1.8mm higher, which will close the slight gap I had on my printer and prevent too much air from coming out there. The outlet side opens about 1 mm shorter so that the air is directed a bit more below the heater block. I have done a few successful prints with this design, and the cooling isn't worse than before. The closed gap also makes it a little quieter. I can't tell if you really need this modification - it's working for me, and that was my intention. And yes, I removed the "HOT" warning on the front (this is facing the heatbed while printing) to get better adhesion. UPDATE: The new "improved" version will print without support. A cheap trick here is to add 2 solid layers (when using 0.2mm layers) between the big hole for the screw head and the smaller hole above for the screw itself. This has to be removed with a drill bit or a small screwdriver, but not having to use support - which is hard to remove inside the hole - is worth it. Print Settings: Printer: Prusa i3 mk2 Rafts: No Supports: Yes Resolution: 200 micron Infill: 100% Notes: I used ABS for this print because PLA so close to the heater block might get molten (especially when not using the fan - as for ABS mostly). For the small "stick" (from 17mm height on), you need a little bit of cooling otherwise it will get messed up. I've done this by the following settings in Slic3r: Auto cooling on Fan speed min 10 max 30 Disable fan for the first 5 layers Enable fan if layer print time is below 10 seconds Slow down if layer print time is below 5 seconds Min print speed 5 mm/s You need some support for the screw hole. I used the following settings: Generate support on Contact z distance: 0 Pattern rectilinear grid Pattern spacing 1mm Pattern angle 0 Interface layers 2 XY separation: 1mm This will create a small support for the screw hole, and since the screw will cover it up, it doesn't matter if it won't look nice. You could modify the design by removing the bigger hole for the screw head and using a longer screw - this will not need any support then. UPDATE: The improved version will print without support.