Spiroid Winglets

After a busy 2 week break, I wanted to do a quick self-contained project to occupy some time. Reading through my list of project ideas, one jumped out - a bullet point that simply said ‘Spiroid’. This seemed perfect and only an hour later I had designed a replacement winglet for my Mini Caelus tiltrotor and was warming up the 3D printer.

Unfortunately my LW-PLA printing profiles didn’t seem to have survived the summer months unscathed, as the print quality left a lot to be desired despite running the spool through the filament dryer. I had split the part up into a few challenging geometries and two straight airfoil sections, so I elected to do the simple parts in LW-PLA and revert to standard PLA for the rest. Before I do any more 3D printing projects, recalibrating the LW-PLA profile is on top of the list of priorities.

After a gluing the parts together, a quick round of balsa filler on some of the more egregious print defects, and two coats of melon yellow spray paint, the winglets were finished. My original winglets were all standard PLA, so the spiroid variants only added 14 g per wing to the aircraft weight.

Weights of conventional and spiroid winglets

Spiroid winglets installed

Sadly due to the clocks moving backwards and winter drawing in, the only free time for flying is on weekends. So on this very cold morning, I headed down to the field and tested the winglets out in flight. As expected, there was no material change in flight performance with the new winglets.

This was just a one-off mini project for fun, so no data or analysis this time, just a collection of photos enjoy below - and a short video available here!