40kW paramotor project

[Hyperious]

Hey all, long time no see.

I'm in the process of building an electric paramotor.

I started flying about 2 years ago on a 2-stroke and now have well over 200hrs of airtime. That said I've always wanted to go electric, and finally with my new job making time for and giving me the equipment to, I've started the conversion process for my old frame from gas to electric.

Right now I'm targeting 40kW max power, with 27kw continuous output. I want to make this thing into a slalom/sunset ripper. The biggest limiting factor of course is batteries, and I plan on using a 24s2p pack of 16000mah 6S packs that are rated for 25C. Total 32Ah of storage at 100v full charge.

My question is what ESC's out there would be the best for this application? I can easily source a Curtis F6 controller that will do what I need since I work for Curtis now, but the weight is high, and software is still in development for driving sensorless applications. Honnestly I'd like to just use a bigass ESC for control since it's just spinning a prop and doesn't need ultra-precise RPM control.

I'm already using a 154mm stator 20 pole outrunner wound to 40kv for power, which should give me about 20% more RPM than my 2-stroke with a ton more torque, but ESC/controller-wise I'm kind of stuck. I've seen some stuff from Flier RC that may work, but I've also seen that they top-out at 25kw based on testing done by members here.

Any advice? should I just stick with a 96v 450A curtis F6?

 

[thepronghorn]

I would probably just use a Curtis if I worked for them.

Open PPG is using an APD esc in the SP140 kit.

 

[Ecyclist]

How is you project going? Any progress?

 

[Two4Seven SuprDan]

how about the BAC8000?

 

[Ecyclist]

BAC8000 is 72V max. He is looking for a controller that can handle 100V.

 

[Jackal21]

Hi, did you finish your paramotor? What motor, esc, battery did you use? I've just made my electric paramotor with the Mad M50 motor, Mad 300A esc and a li ion 32A 88v nominal 2.8kwh battery and I love it. Some details in the video of my first flight

 

[Ecyclist]

A fantastic job. Congratulations!
Can you post how much thrust does your build produce?
Thanks.

 

[Jackal21]

A fantastic job. Congratulations!
Can you post how much thrust does your build produce?
Thanks.

Thank you!
The Mad M50 motor is considered to produce about 70kg thrust with the 140cm prop at 20kw, info found on the OpenPpg community forum.
With my battery I can go to about 15kw, above that the voltage drop is to high. So I have maybe 50 kg thrust. All I know is that recently I had a flight and at 10kw I had 2.7 - 3 m/s climb, more than I need. I usualy climb slowly with 0.7 - 1m/s at 5-6kw.

 

[Ecyclist]

Thank you for the info.

 

[nicobie]

Pls be careful!

Nice job!

 

[Jackal21]

With the help of a friend I've managed to lighten my electric paramotor with 11kg from 36 to 25kg and still have the 30min flight time. Now it's a dream to fly! I've changed the 2.8kwh 32Ah 88v 17kg (2.5kg alu case, 13kg the cells) 21700 battery with a 30Ah 9kg semi solid lithium batt, that gives me same flight time of 30min but is 8kg less. Also the M50 4.2kg motor with the V135L 2.2kg motor and motor plate with a cnc lighter one.
Works fantastic, brings me so much fun and want to encourage others to try it so check it out!

 

[fechter]

That looks great! Nice landing.

 

[Logic11]

With the help of a friend I've managed to lighten my electric paramotor with 11kg from 36 to 25kg and still have the 30min flight time. Now it's a dream to fly! I've changed the 2.8kwh 32Ah 88v 17kg (2.5kg alu case, 13kg the cells) 21700 battery with a 30Ah 9kg semi solid lithium batt, that gives me same flight time of 30min but is 8kg less. Also the M50 4.2kg motor with the V135L 2.2kg motor and motor plate with a cnc lighter one.
Works fantastic, brings me so much fun and want to encourage others to try it so check it out!

Nice!
If you want to further improve it; try aerofoil, elliptical tubing for the safety frame:
Like this:

Or this:

Round Bar/pipe Cd: ~1.17
Aero teardrop (wing) shape Cd: 0.045 (26X lower than round)

You will notice a decrease in prop noise too. (see: Blade passing Stator noise)

A pusher prop spinner like this might also be worth a try:

It adds a bit of weight, but the aero and motor cooling advantages may make it worthwhile.

The NTX Spinner

NB that both ideas are easy and safe to try with some hot wire and Styrofoam ingenuity. For science!
(If some Styrofoam falls off during testing; it wont hurt or break anything)

 

[Jackal21]

Nice!
If you want to further improve it; try aerofoil, elliptical tubing for the safety frame:
Like this:

Or this:

Round Bar/pipe Cd: ~1.17
Aero teardrop (wing) shape Cd: 0.045 (26X lower than round)

You will notice a decrease in prop noise too. (see: Blade passing Stator noise)

A pusher prop spinner like this might also be worth a try:

It adds a bit of weight, but the aero and motor cooling advantages may make it worthwhile.

The NTX Spinner

NB that both ideas are easy and safe to try with some hot wire and Styrofoam ingenuity. For science!
(If some Styrofoam falls off during testing; it wont hurt or break anything)

Thank you for your interest! I thought about adding eliptical shape stirofoam around the prop ring but because I keep those semi circles that form the ring in a bag for transport, something too soft won't last. Plus the net is on the ring so it would have to pass through those eliptical shapes somehow.
But I saw that some companies make eliptical shaped rings now.
Those carbon spiners look awesome, I have one on my 27% rc gas plane. But, in order to take it off I have to unscrew those tiny bolts around it and it takes time.
Interesting points thought, thanks!