Peter Sripol 50 prop design

Fun video to watch. Interesting he used wireless throttle to start, then switched it to an openppg throttle.

LOL ya beat me to it, could not help checking this out , i mean talk about going form one extreme to another , and to think we were worried about flight duration :slight_smile:

I agree this was entertaining, but I found myself disappointed that he didn’t give it the attention needed to show its true potential. For example, he admitted that he oversized the prop shrouds and this spoiled the thrust. It seems to me also that using so many discrete motors should have been exploited to position them in a different configuration with more of them to the sides away from the pilot’s body which blocks their airflow. I’m not a mechanical airflow designer, so I can’t but wonder if the shrouds could also have been more effective if their trailing edges were serrated or fluted as done with jet engines and for the motors of the Lilium EVTOL. And then there are all sorts of unanswered questions about the power management system and the batteries and how much endurance might be obtained from a more thoughtful design and configuration.

I have work with comparable drone motors in my year of flying fpv. Those motors typically produce around 1.5-2 grams/watt thrust efficiency in the thrust range that Peter was holding them in during flight. I ran some generic numbers an found that they were probably consuming well over 6.5kW power just to maintain altitude if they had the perfect setup with those motors (which they didn’t). It’s an awesome project, but the efficiency will never reach a point with those drone motors such that it could get flight times close to something like the OpenPPG X4 let alone the SP140.