What would be the consequence of mounting a 125cm prop on the stock setup? Of course it would reduce thrust, but if you are a lightweight person it seems thrust would still be enough.
Would a two- or three blade propeller be best? I assume it would make more noise, is that correct?
Just thinking this would make the rig extremely portable, given an appropriately sized cage.
Would it even fly?
Basically you want to go bigger and lower rpm if you want it to be more silent.
3 blades are louder than two.
if the motor has the same speed and you reduce from 140 cm to 125 cm, the eppg becomes quieter overall. Of course, as you say, it loses efficiency. if you want to do 125 cm, definitely use a 3 blade because it is quieter because it has less pitch. I’ve been flying a 122 cm three-blade since about 2012 with a body weight of 85 kg. the performance is enough to have a lot of fun. of course, my current models have large propellers (150 cm) to be efficient and quiet at maximum speeds below 2000 rpm.
a lot is explained very well here:
here you can calculate the speeds of the prop tips. as well as the efficiency:
122 cm 3 blade : Dudek Universal 1.1 e-ppg electric paramotor DIY EPPG motorschirm carbon paramotor - YouTube
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I have flown a 125cm prop after I damaged mine.
Watch to to make sure it spins the correct direction.
I had a CW prop from a gear reduction paramotor I used to own and decided to use that spare prop after I tipped my 140cm. I revered the motor direction from the software of the ESC.
As soon as I launched I went into the gnarliest left torque induced turn I have ever experienced. I was able to weight shift right, trim out the left side, and pull medium right brake pressure to fly straight but it was far from enjoyable or safe. I landed after that flight and decided I’ll just wait until either my prop is repaired or my new one arrives.
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Did you use the stock weight shift arms with this opposite-direction prop/motor configuration?
I used the stock weight shift arms yes, so I was experiencing a weight shift correction in the direction of torque from the CW prop. TORQUE MULTIPLIER!
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Haha, yeah, I imagine that would be a lot to handle! I came to this from an Atom 80 and the torque of this thing even with the correct torque offset is still scary to me.
cheers mate. i just read you reversed motor direction in ESC options. since i get zero response from email. can you tell me if there is an option to manually set low voltage cut higher lets say around 83V so i can use lipo packs? whats the software we use for this ESC called? i will get my SP140 but because i am living as expat in asia i cant get a battery shipped easy. no problem making one. i will also test other props-