I (37) really like paragliding, but I was very frustrated after a time, because I live in the flatland, and the possibilities to fly are very limited. To fly in the mountains, I need eight hours by car, on paragliding travels the weather was often not so good, to fly from small hills (1-2 by car) was often not so safe (close to terrain, ‘path starts’) and its hard to get up, and at winches you have to wait a long time. Here nearby on average two hours (I made ~ +150 winch flights). It was very difficult, and the relations between effort and great moments was poor.
I bought a small ‘unroll winch’ on my own, but do not find a good area to use it legal. It’s here very hard to find a place. Lots of regulations and most of field paths are owned by authorities.
I talked with some paramotor pilots in the past, many of them told me that is it so great, and the window for flying is much bigger, but all of them told me, that it is not so funny to fly thermals with it, because of the additional weight and the sidebars. Most pilots with motor on youtube fly when the air is smooth und it seems that they try to avoid any turbulence and uplift.
Last year I start thinking about, how a paramotor could looks like, without sidebars. For my glider (very sensitive for flatland thermals, very save compared to other high end b wings, 10kg left) and my harness. I need much time and and lots of temptations to find this. I still do not want to change here anything.
I am very familiar with electric motors, I have done a lot of advanced rc projects in the past, (own flight control system for rc helicopters and drone, I build one of the first variable pitch quadcopters in the world) and several rc models since the age of 10. I am not familiar with gas engines. I never thought about gas engines in the past.
So I start my own electric project after I made some test with tubes. I bend tubes and add weight, and run around with it and sat in the simulator and made roll and nick movements, and discover that it should be possible to fly thermals with it, and that I can’t feel it when I sat in it (the best thing). But, it has to be light. With 8,6kg in total yes, that’s it, with 10kg ok, with 12,5kg, hmm no. Especially when you turn around fast for backward start and your frame is so long (two motor version).
For me very fascinating was the project “Sunny Paramotor”:
It’s a tiny ~10kg system (with 4 lipos) and he can fly. So I was pretty sure, that a light weight electric engine is possible. I try to find out, why sunny paramotor flies. I use ecalc.ch and discover that he do not have so much thrust, but the speed of the airflow is high. So the difference between moving air in flight und thrust of the propeller is higher than normal. Maybe that is the key for lightweight systems. I have the same weight (80kg) and similar glider (mentor 2 and nevada 1) so my frame should fly also, when I use the same principals.
and I try to do it better , two in sum lighter engines (no torque), no cage and netting, and blades with much more pitch (24x16 with 14s). In ecalc.ch this was the best solution. But currently I am not so sure. Thrust with 12s is less than expected and my flight time is much lower than “sunny paramotor” with 4 lipos. High pitch blades produce a lot of noise (also two, one single is quieter, there are interactions between the two aspirating propellers even with big distance) and noise is always a sign of whirls and these whirls need also energy. And I have sometimes problems to start backward, so I don’t think I will step up to 14s und will instead discover a single motor version next. All other things runs so far really good.