Dr Mad Thrust alternate blades

thingiverse

Straightforward problem here. Bought six Dr Mad Thrust 50mm five-blade props for a project. Then realized I really needed three clockwise and three counter-clockwise versions, with no spare blades to fall back on. Borrowed code from Linear or Parabolic: https://www.thingiverse.com/thing:689564. Aerofoil design came from https://www.thingiverse.com/thing:2790219/comments. Had to hack the code to get snug fits and dropped a couple of features in the hub. Added a disc to the hub as well. Note that the original aerofoil version opted for razor-sharp trailing edges, which led to failures during printing, removal from bed, or operation. So I clipped the trailing edge with a disc since the blade is at an angle anyway. Produced CW versions by reversing them in my Flashfinder software. The metal hubs aren't designed for reverse operation, but the fit is tight and a dab of epoxy solves the issue. Went for pusher and puller versions of NACA blades, as linear blades are low efficiency in bi-directional use. Author of the blades worries that they might be expected to perform too well if used as a drone set. In fact, I plan to fill a pool toy (Nemo) with helium to turn it into a blimp floating around the pool area. Performance requirements are less, but we'll see how it goes. The blimp design will be based on the impeller setup of the Saab Double Eagle. Building a frame from 10mm OD carbon fiber tube and attaching rear motor brackets. What did you say? Will it float with all that weight? Who knows! We'll find out, I guess. Meanwhile, playing with ROS UUV simulator to see about HIL, since a blimp is essentially a UUV in the air – if you get my drift.