HI guys...this is not part 2 but interim reply...
Firstly, Single big unit fan or engine that produces twice the amount of thrust has been proven everytime better than to have duplicate units except for safety redundancy. The weight savings alone is enough reason. A mere arbituary 25% weight increase would double power ratings as oppose to 100% for duplicate units.
However having said that I can understand why it is common to come to that conclusion of two, I understand may be your set up (motor batt and fan) combination is already at optimum or near optimum, as such if you double increase the voltage of batt or change the motor or just change a new fan, you have realise the increase in thrust is not apparent, as such it is better to have two duplicate units running at optimum to double the thrust. I have personnally came to that conclusion. What I had realise later was that this is where the problem lies with EDF. When we find we do not get what we want, we change something, fan, motor, batt,...the pemutation is almost non exhausting...hence the common conclusion.
However later I have learnt, to increase thrust, the whole set up needs to be changed to produce the required result. Eg, 55mm fan on 3S on 3900KV 250w is a reasonably efficient set up, However to increase the thrust any further, 55mm fan needs to be on 4S 2500-2900KV >250W. If you want a bigger fan say 64mm fan, 3s 3200kv.>300w would yield good results. However if you only change one item from the basic configuration like a higher kv motor, or higher wattage motor or just run on 4S or just change the fan, the set up is set up for disaster not only for powerplant also for your plane.
Cheers.
Part 2 on the way...
Firstly, Single big unit fan or engine that produces twice the amount of thrust has been proven everytime better than to have duplicate units except for safety redundancy. The weight savings alone is enough reason. A mere arbituary 25% weight increase would double power ratings as oppose to 100% for duplicate units.
However having said that I can understand why it is common to come to that conclusion of two, I understand may be your set up (motor batt and fan) combination is already at optimum or near optimum, as such if you double increase the voltage of batt or change the motor or just change a new fan, you have realise the increase in thrust is not apparent, as such it is better to have two duplicate units running at optimum to double the thrust. I have personnally came to that conclusion. What I had realise later was that this is where the problem lies with EDF. When we find we do not get what we want, we change something, fan, motor, batt,...the pemutation is almost non exhausting...hence the common conclusion.
However later I have learnt, to increase thrust, the whole set up needs to be changed to produce the required result. Eg, 55mm fan on 3S on 3900KV 250w is a reasonably efficient set up, However to increase the thrust any further, 55mm fan needs to be on 4S 2500-2900KV >250W. If you want a bigger fan say 64mm fan, 3s 3200kv.>300w would yield good results. However if you only change one item from the basic configuration like a higher kv motor, or higher wattage motor or just run on 4S or just change the fan, the set up is set up for disaster not only for powerplant also for your plane.
Cheers.
Part 2 on the way...
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