Hello and I have a question

[Scunner73]

Hello All

Just joined this forum but have been flying quads and planes for a couple of years.

Just putting together my first home-build quad and have chosen the multistar 4830 480kv motors. Its a 600 size quad but I wanted the best payload possible. My question is that the 4830 480s are a 6s motor but what would the effect be of using a 4 or 5 s lipo instead?

I think I will stick to the 6s as they seem to give longer flight times but wondered what the consequences would be of using less cells.

Scunner

 

[French]

Decreased cells = less voltage = fewer revolutions of the motor = less thrust (if the propellers stay the same)

The max voltage for a 6S battery is 25.2V. With your 480kV motor, that's a max revolutions of ~12,100/min
The max voltage for a 4S battery is 16.8V = ~8,000 rpm or 67% of the rpm of the 6S

Depending on the space you have available, sometimes you can increase the size of the prop to have the same amount of thrust.

As far as flight times are concerned, that's more of a function of the mah (the weight can also be a factor in some setups)

 

[Craftydan]

I think I will stick to the 6s as they seem to give longer flight times but wondered what the consequences would be of using less cells.

Assuming you've sized your power system well . . . lower payload, smaller battery capacity, shorter flight time.

Keeping the voltage higher, assuming you've selected the right prop for the voltage and the motor's KV is slow enough, allows you to run at a lower throttle, and the motor runs with less current for the same thrust out. The lower current draw typically pushes the motor into more efficient conversion of Electrical power into torque, so less power is wasted in heat.

This also means you will have more head-room before the motors begin to struggle under the load. This can be used for either more payload than the lower voltage could support or even larger battery packs before the diminishing returns of the extra weight catch up with you.

 

[Scunner73]

Thanks French, that's great info.

I will bear it in mind. I was also just worried that if I used a lower s battery than recommended it would affect the stability of the motors.

 

[Scunner73]

Thanks

Assuming you've sized your power system well . . . lower payload, smaller battery capacity, shorter flight time.

Keeping the voltage higher, assuming you've selected the right prop for the voltage and the motor's KV is slow enough, allows you to run at a lower throttle, and the motor runs with less current for the same thrust out. The lower current draw typically pushes the motor into more efficient conversion of Electrical power into torque, so less power is wasted in heat.

This also means you will have more head-room before the motors begin to struggle under the load. This can be used for either more payload than the lower voltage could support or even larger battery packs before the diminishing returns of the extra weight catch up with you.

Thanks Crafty

I've gone with 480kv motors, 6600 mah 6s lipo and 15 inch props. the AUW is 2.7kg and the frame is rated for at least 3kg so I have some room left in the payload area. On a sidenote if anyone has any tips on D/R and expo for a 600 size quad I'd appreciate the benefit of someone else's experience. I want it very docile for nice steady filming so I'll most likely stick close to the settings on my discovery pro but I'm open to suggestions.

Thanks again

 

[TheAdviser99]

Decreased cells = less voltage = fewer revolutions of the motor = less thrust (if the propellers stay the same)

The max voltage for a 6S battery is 25.2V. With your 480kV motor, that's a max revolutions of ~12,100/min
The max voltage for a 4S battery is 16.8V = ~8,000 rpm or 67% of the rpm of the 6S

Depending on the space you have available, sometimes you can increase the size of the prop to have the same amount of thrust.

As far as flight times are concerned, that's more of a function of the mah (the weight can also be a factor in some setups)

Thanks French for details