Folding props for less drag?

[GliderPilot (Paul Butler)]

What you are talking about is a ducted fan. That concept has been discussed several times on this forum and has always been shot down by people with experience. Type ducted in the search of this forum and you can research it more. Here is a link to one thread:

Why four motors, instead of one motor?

Yeah, I’ve got experience with ducts. They won’t make sense for this application. In order for ducts to add efficiency, you need tight tolerances on the separation between the prop and the duct. The shape of the duct also matters a lot. So it’s pretty hard to do. Now, let’s say you managed to deal with the above, using a duct wrecks your portability, and also adds a bit of cross sectional drag. So, overall, I don’t think they’re appropriate for this design. Now if you’re talking EDFs - lik…