12kg AUW with 5s setup?

[urancle]

Hey guys,

I'm flying a flat octocopter with a AUW of 9.8kg. My Setup is an aerodrive Powerboard (8x40A) with Axis 2826/12 motors, 14" props. We did a short test with 12kg AUW, but the motors got too hot. The aerodrive is only capable for 3-5S, that's why an upgrade to 6s would cost a lot. Before i spend thousands i want to ask you; is there any chance to fly a 11-12kg AUW with a 5s Setup?

Maybe set up as an X8 with 16" propellers? I know i would lost some flight time with an X8 compared to the flat. But i don't care about the flight time as much as about the motor heat. What do you think?

Thanks for any help.

Cheers

 

[Ghostrider]

There is no reason why 5s can't lift 12kg. Since you are running 5s vs. 6s, you would just need to find a motor that is the middle of the road kv. I would suggest 400 - 500 kv and something that will put out 3KG of thrust at that voltage. The T-Motor MN4120 465kv motor would put you in this range. You could do a flat 8 with 14" props or an X8 with 16" props. As with any build, I would suggest buying a single motor and doing some bench testing to see if you can achieve your goals. More importantly to test the ESC/Motor compatibility.

 

[tahoelight]

Well if it means anything, I am flying a 9kg flat Octo with t-motor 2826 550kv motors with 14x6 props on 5s. It hovers at 50% throttle perfectly and I get about 10 minutes of flight with 16,000mah. I think it will fly at 12kg but with shorter flight times. Also, I would up the ESCs for some safety margin.

 

[Kari]

I'm flying coax octo 10-12kg (depending on camera on board) with 2x 5s 10000mah with 3515 650kv with 14x5 props and it's been my best copter so far. I'm currently stress testing my new build with U7 490kv and 17x5 props which i had first plans to go with 6s, but actually i don't see much benefit going to 6s over 5s. The U7 machine will hover 13kg auw at 45% power with 5s. If i went to 6s i need to reduce prop size and then i'll lose some flihgt time so end result is pretty much the same.

Best regards,

Kari

 

[jackwrangham]

Hi Urancle

I think your question has been answered by the guys above! Just wanted to say we're about to move to a 7S set up on our systems, so we have 22 5S Gensace 10ah lipos for sale. They were bought back in November, so used a bit, but still very healthy and well looked after packs, 6 of them have barely been used, maybe 2-3 flights with them. They have EC5 connectors.

Let me know if you're interested! Cheers

Hey guys,

I'm flying a flat octocopter with a AUW of 9.8kg. My Setup is an aerodrive Powerboard (8x40A) with Axis 2826/12 motors, 14" props. We did a short test with 12kg AUW, but the motors got too hot. The aerodrive is only capable for 3-5S, that's why an upgrade to 6s would cost a lot. Before i spend thousands i want to ask you; is there any chance to fly a 11-12kg AUW with a 5s Setup?

Maybe set up as an X8 with 16" propellers? I know i would lost some flight time with an X8 compared to the flat. But i don't care about the flight time as much as about the motor heat. What do you think?

Thanks for any help.

Cheers

 

[urancle]

many thanks to your suggestions!

I have to think about it... I will first follow your suggestion Ghostrider and buy a single motor. I'm not shure if the Aerodrive can run this bigger motors (it uses the MK BCtrl 2.0 on it, but "upgraded" for 5s). But maybe i keep the Cinestar how it is using it only for stills. I'm thinking about buying a Kraken 130 for the BMPC4K. Besides some bad stock motors and ESCs from the RTF packages there are a lot good things about it to read.
If I'll buy the K130, i'd need 6s anyways, so i would contact you Jack. Thanks again!

 

[R_Lefebvre]

There really is not any direct connection between voltage levels and heat. A lot of people think that higher voltage is "just more efficient and generates less heat" but that's completely false. It's much much more complicated than that.

 

[Ghostrider]

I find that in some cases higher voltage can produce more heat if paired with the wrong motor and ESC. If the motor is too powerful and has to run at a low throttle percentage, then the ESC is more likely to run hot because the FETs on the ESC are off more and the motor generates more heat in the diodes. It is important to find the right balance of motor power, motor kv, propeller, and battery voltage. I recently did some testing with a larger motor and I could not find an ESC that liked to run at 50% throttle. Even though the current ratings were 3-5 times the amount of current I was drawing, they just overheated. We ended up going with a smaller motor.