How to choose the right motor, ESC and Propellers

Hi everyone, I am new to this and I was nocked by a rock wall. My goals in this drone are for it to hover and to have a flight time of 25-30 minutes. I have estimated total weight of 1300 g, taking into consideration all of the components.

Motors:
I found a rule of thumb that recommends multiplying the drone’s total weight by 2 and adding 20% more margin of error. 1.3*2.2= 2.86 Kg. this ends up with a total of 715 Kg of thrust per motor. Now the voltage was calculated by multiplying the thrust times 3. My final numbers were Thrust=715 Kg, Voltage=2145 Kv.

ESC:
I was thinking of buying a 4 in 1 ESC with 45 Amps. I think a 45 A is somewhat bigger than what I need, but is there anything wrong with a bigger ESC?

Propellers:
The largest propeller that my design allows is 9 inches long, meaning 9045 propellers.

Please feel free to drop any recommendations. Everything helps.

Thank you.

How on earth did you end up with 715kg per motor, and even worse. The voltage??? Like that would kill you. At most, we run 12S, which is around 50V. Now over 2 million volts? That’s wayyyyy toooo high for anything. Drone related or not

Do you have any other goals except for the 25min flight time at hover? Because the setup that you have rn would be way overkill, completely wrongly calculated, and a waste of money imo

now that I’m reading through it I noticed that I messed up all of my units, they are all on “g” and “v” you can take out the “K”. Now, I do not need any other goal, I believe that a 25 min flight and hover is good enough.

Well then, that voltage is still a bit too much. You could probably get away with just using 6s, which is at max only 25V.

Also, for that kind of application, you would be much better off with a smaller quad, probably 7" with these motors: https://emaxmodel.com/products/pre-order-emax-eco-ii-series-2807-1300kv-1700kv-1500kv-brushless-motor-for-rc-drone-fpv-racing https://shop.iflight-rc.com/index.php?route=product/product&product_id=1001&search=xing https://shop.iflight-rc.com/index.php?route=product/product&product_id=1473&search=xing

On a decently sized 7" frame: https://shop.iflight-rc.com/index.php?route=product/product&path=25_32_110&product_id=926 https://shop.iflight-rc.com/index.php?route=product/product&product_id=1386&search=chimera https://www.project399.com/products/super-g-extended

With a flight controller that supports ArduPilot: https://ardupilot.org/copter/docs/common-omnibusf7.html https://ardupilot.org/copter/docs/common-matekf405-se.html https://ardupilot.org/copter/docs/common-holybro-kakutef4.html https://ardupilot.org/copter/docs/common-matekf405.html

A decently beefy ESC: https://www.diatone.us/products/mamba-f60pro-dshot1200-4in1-esc-60a-6s-30-30mm https://www.diatone.us/products/mamba-f50pro-4in1-esc-dshot1200 https://store-en.tmotor.com/goods.php?id=1014 https://www.banggood.com/cs/IFlight-SucceX-60A-V2-Plus-2-8S-BLHeli_32-4-in-1-Brushless-ESC-DSHOT1200-Dshot1200-w-35V-220uf-Capacitance-for-RC-Drone-p-1393226.html?rmmds=detail-left-hotproducts&cur_warehouse=CN https://www.banggood.com/cs/Upgrade-30_5x30_5mm-Holybro-Tekko32F3-Metal-65A-BLheli_32-4-6S-4in1-ESC-DShot1200-w-or-F3-MCU-and-Current-Sensor-for-RC-Drone-FPV-Racing-p-1414818.html?utm_source=googleshopping&utm_medium=cpc_organic&gmcCountry=CZ&utm_content=minha&utm_campaign=minha-cz-cs-pc&currency=CZK&cur_warehouse=CN&createTmp=1&utm_source=googleshopping&utm_medium=cpc_bgs&utm_content=sxxx&utm_campaign=sxxx-ssc-cz-cs-all-0122&ad_id=493831220865

And a good compact GPS unit: https://www.getfpv.com/hglrc-m80-gps-module-for-fpv-drone-racing.html http://www.mateksys.com/?portfolio=m8q-5883 https://www.team-blacksheep.com/products/prod:tbs_m82_gps https://www.hglrc.com/products/hglrc-m80pro-gps-qmc5883-compass-for-fpv-racing-drone
(Keep in mind that some of these don’t have a compass, so you might need to get that one separately)

Then the rest is up to if you want it to be FPV or not, so if you want to, I could throw something together there as well. I am for the most part an FPV pilot, so this is the best way that I know off to achieve automation on a quadcopter. There might be other ways around it, but I would rather only speak about something that I have personal experience with :wink: