Designed this impeller for my dust extractor setup, as you can see from the vid it is on top of a Miele washing machine motor. Which is turn is being speed controlled. Maxes out at 500W and 3000 RPM, by which point the impeller is really sucking air very nicely. Here is youtube vid of it in action:
This design has a 10mm shaft running through it, I could probably mod this and scale the model if you like. Tips welcome of course :). The cuts etc on the base are to help it print, reduces warping. I actually printed with relatively low infill, and 1.2mm walls - pretty terrifying when spinning up for the first time, I was concerned it would explode, but so far so good!
Dont ask me what the static pressure etc etc etc characteristics are - I have no idea! This was designed by looking at compressor impellers, and then just trying to figure it out. Although there is good info online about forward/radial/reverse style blades, if there is info about the best practices on how to actually implement them, then it must be held by a bunch of ninja monks on a remote Japanese mountaintop because I sure as hell couldnt find anything online. Even regarding a simple question like whether there should be a constant cross section of flow - nothing. So I printed two smaller test impellers and, curiously, the one without a constant area had the highest flow.
Picture shows the inside with the blades, without the roof or whatever it is called - second smaller blades have an aerofoil shape to them. I just suppressed later parts of the design for this pic, so it doesnt have all later features.