Jul 29, 2015, 12:08 AM Registered User Joined Feb 2015 23 Posts Discussion Quadcopter opinions and battery help http://www.hobbyking.com/hobbyking/s...ame_600mm.html https://www.hobbyking.com/hobbyking/...dProduct=12921 9x4.7 props Plush 30A ESC This is my first quadcopter ever. I was too exited and didnt check my cart and now im seeing that my motors are too big. Should I change them or do I buy a bigger battery? Probably gonna make it FPV with a gopro. Current battery Turnigy 2200mah 30-40C 3s
 Jul 29, 2015, 01:16 AM Research Junkie Canada, BC, Duncan Joined Jun 2015 132 Posts Hello, You'll need to spend some time calculating allot of things. Are you really good at math? It will help. You'll need to estimate the take off weight of your machine. 1.4kg maybe. multiply that by 2.2-2.5 (depends who you ask) so 3.08-3.5kg. Then divide by 4 = 770-875g of thrust you'll need to make it fly. So then you'll need to look at the spec sheet and see what prop and battery you need to get your motor to give 800g of thrust. From that you can demine the max amperage you need for you ESC. That's a start. at first glance the motors don't seems too big. spec say to use a 28-xx sized motor.
Jul 29, 2015, 12:05 PM
Registered User
Joined Feb 2015
23 Posts
Quote:
 Originally Posted by DaGriff Hello, You'll need to spend some time calculating allot of things. Are you really good at math? It will help. You'll need to estimate the take off weight of your machine. 1.4kg maybe. multiply that by 2.2-2.5 (depends who you ask) so 3.08-3.5kg. Then divide by 4 = 770-875g of thrust you'll need to make it fly. So then you'll need to look at the spec sheet and see what prop and battery you need to get your motor to give 800g of thrust. From that you can demine the max amperage you need for you ESC. That's a start. at first glance the motors don't seems too big. spec say to use a 28-xx sized motor.
Yes i can math! It says max pull is 890g with a 2s 10x7 prop, 4s 8x4. Im going 3s 9x4. So i think im good there? Yes no idk. Max AMP is 21A, so i got a 30A for possible future upgrade. Max power is 210watt.

The thing is i already ordered all of this. So should i just change the motors or buy a 3000-3300kv with high discharge?

Im not very experienced with RC stuff as you can see.
 Jul 30, 2015, 01:11 AM Research Junkie Canada, BC, Duncan Joined Jun 2015 132 Posts I think what you have is going to work fine. The best thing you can do is set it up and fly it and see if your happy with the performance and flight times. If you get a faster spinning motor higher Kv, then you'll need to get a smaller props. Also a faster spinning motor with a small prop uses more energy than a slower motor with bigger prop. For example I have 800kv motors with 11x5 props. Mx draw is abou 12-13a. So I have 20a esc, on 3s power. You might have been able to save some \$. Again, just build it and get it in the air before you spend more money. Then upgrade as you need too to get the performance you want.
 Jul 30, 2015, 02:38 AM Research Junkie Canada, BC, Duncan Joined Jun 2015 132 Posts Check this out,
Jul 30, 2015, 07:16 AM
FA3PR9WM79
United States, VA, Richmond
Joined Dec 2013
6,184 Posts
Quote:
 Originally Posted by cdaher http://www.hobbyking.com/hobbyking/s...ame_600mm.html https://www.hobbyking.com/hobbyking/...dProduct=12921 9x4.7 props Plush 30A ESC This is my first quadcopter ever. I was too exited and didnt check my cart and now im seeing that my motors are too big. Should I change them or do I buy a bigger battery? Probably gonna make it FPV with a gopro. Current battery Turnigy 2200mah 30-40C 3s
I'm running 2212's on 3000mAh 3S Zippy LiPo, swinging 1045 props.

I'm using an APM 2.6 with GPS, 915mHz Telemetry radios, 700 line camera, 5.8gHz 200mW video transmitter, and MavLink OSD.

Video Rx is a Boscam RC805. I have a 7" TFT monitor attached to the radio and I also have the Qunanum V2 goggle. I'm waiting for an RC305 rx so I can separate the monitor and the goggle. I use a 2S 1300mAh Nanotech LiPo to power the RX and monitor, and a separate 1000mAh Lipo to power the goggle. I did this to keep the RX from overheating...

To get ground station functionality I have the 3DR ground radio connected to my Android smartphone and I run 3DR's Tower app. The phone is mounted to my transmitter with a Walkera Type B phone holder. The ground radio is held to the monitor sun shade in a cloth pouch...

With the battery installed, the aircraft All Up Weight is 1543 grams. Flight time is around 7 minutes with 2000mAh used.

Images

Jul 30, 2015, 07:43 AM
FA3PR9WM79
United States, VA, Richmond
Joined Dec 2013
6,184 Posts
Quote:
 Originally Posted by cdaher Yes i can math! It says max pull is 890g with a 2s 10x7 prop, 4s 8x4. Im going 3s 9x4. So i think im good there? Yes no idk. Max AMP is 21A, so i got a 30A for possible future upgrade. Max power is 210watt. The thing is i already ordered all of this. So should i just change the motors or buy a 3000-3300kv with high discharge? Im not very experienced with RC stuff as you can see.

Actually, motor/battery selection is counter intuitive.

For a small, light aircraft like a 250 FPV racer you want high kv motors, "small" props and 3S "high discharge" LiPos.

With a heavier aircraft like a quad or hex photography rig you want low kv motors, 4S or 6S LiPos and big props.

As an example, I run 2212-1000Kv, 3S 3000mAh 20C LiPo, and 1045 props on my X-525 FPV rig. On my Tarot 680 Pro hex, I run 4006-740Kv, 2 4S 5200mAh 10C LiPos in parallel, and 1355 CF props.

With the X-525 I get about 8 minutes of flight time. With the 680 I get about 20 minutes...