Another parametric fan (FreeCAD exercise) by olavl

Last crawled date: 3 years ago

This is an improved version of my previous fan. This one has a curve applied to the edge of the blades, which seems to be the standard with cooling fans for PCs and other electronics. I have also reduced the number of blades from 8 to 7. This new version should be quieter and perhaps even move more air.
Again I made this just as an exercise with FreeCAD.
I am just a beginner at CAD and FreeCAD but I am trying to learn it "the right way", that is, by applying principles of parametric design. You may want to try this:
(If relevant) Set the FreeCAD language to English to make the instructions below easier to follow: in the menu "Edit" choose "Preferences" and on the "General" tab choose English.
Open fan2.fcstd in the program.
In the "Combo View" panel on the left, on the "Model" tab, double click the "Spreadsheet" object. The spreadsheet will open.
In the menu "Windows" choose "Tile". The 3D view and the spreadsheet will be shown next to each other, more or less like in my screenshot (see https://www.thingiverse.com/thing:2996660)
Now you can alter the values of the different parameters. If you change a value and hit Enter, all the internal dimensions that depend on the parameter are recalculated automatically. The result will be shown in the 3D view immediately.
If you are satisfied with the result, in the "Model" tab click to select the "rotor_complete" object (this represents the complete fan) and from the menu "File" choose "Export...". If you export as type "STL Mesh *.stl" you have a file that you can slice in Cura or whatever for printing.
This way, with just one CAD file, you can create many size variations of the fan for different applications.
Comments and questions are welcome. Also if you use this in some way, please let me know by leaving a comment here. I would be delighted.
UPDATE 2018-07-30
I uploaded another version of this, fan2_v2. This one lets you configure the pitch (angle) of the blade.
A factor of 7 (equal to the number of blades) results in the leading (upper) and trailing (lower) edges of the blades to overlap slightly. A higher factor results in smaller blades that do not overlap, and steeper angles.
This might be better for 3D printing without supports. The downside is it will probably move a bit less air. In the STL file that I also attached as an example a factor of 9 was used. If anyone prints this, please show me the results. My own printer is out of repair at the moment.