I am very new to multirotordrones and I decide to learn how to build one myself.
Technically I am thinking to build two drones, one 7” quadcopter and one 10” quadcopter.
So far I only did research on FC, ESC, Motor, battery and prop size, I haven’t dug into other parts, such as receiver, GPS, or analog cam, yet. For now, I just want to make sure I am heading to the right direction and getting the right parts for the drone I am going to build.

First, for the 7’’ quadcopter. I am aiming for a long range, high efficiency cinematic FPV.
 
FC: F7                I saw many demo videos and budget build videos on YouTube, and I decide to go with a F7 stack flight controller for this model. It is an easier start for me and less wiring and soldering I need to do. I haven’t decide on any brand yet (There are so many brands like holybro kakute, iFlight, etc.) I can choose from and there are review videos, so I am not so concerned about the brand, and I know F7 will give me some headroom for future firmware update.

Motor:1300KV-1700KV        I know the efficiency is decided by the combination motor(amp draw), prop size, battery (size and voltage) and the weight of the quad. I won’t do a lot of freestyle or racing, because I am just not that skilled, so is this right KV range for a 7” quad?

Propeller:7x4.2 2-blade         I want to use a 2-blade on the 7” instead of 3-blade. What is difference between a 2 blades and a 3 blades on quadcopter. I see 3 blades on 7” quad very often, but I don’t understand why.

Battery:6S li-ion      Li-ion battery can increase the flight time comparing to li-po battery, right?


That’s what I have decided for the 7” quadcopter so far, if there is something doesn’t look right, please let me know. I am not ask anyone to do the work for me, I just want to know if everything above sounds like a good start, and from there I can narrow the selection down.

For the second quadcopter I want to build, I have a lot uncertainties.
This 10” quad will be used for aerial filming, and I want to be able to stay in the air for about an hour (when it is not carrying any heavy equipment). With a low KV motor(900KV-1100KV), a 1045 propeller, and a 12S battery pack should be able to achieve this, right? Then, because the voltage is too high for most of the F7 FC, I think it is best to follow the same build-up of a X-class/Beast quad, right?

This is a general idea I have for this 10” quad. Does it sound practical? If it sounds alright, then I can choose the parts for this drone based on the X-class build up I see on YouTube. Unless some changes can be made here, or what I am think here is no right and I need a different design.

I very appreciate all the help, any comment, any suggestion, a video or a picture of similar build up will be helpful to me. I am new to FPV drone, the more feedback I get, the more I learn.


Thank you
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You analysis for a 7 inch is pretty dead on. But I would post your questions in the long range forum. You probably get more responses.

As for 10 inch, the 1 hr flight time might not be realistic. It is difficult to find 12S ESC. Only APD makes them. Secondly, even commercial companies like DJI really haven't achieved it in a quad configuration. Their latest Matrice 300 RTK is only getting 55mins. And this thing cost $8600. If you are looking for better flight time, you probably looking at least a hex configuration and longer props. Long flight time is really out of my knowledge. If you want to build an X-class with 3-5 mins, I am glad to help.

One thing to keep in mind is you will probably crash within the first 30 seconds of flight for your first few weeks till you get a feel for it (seriously). 7" and 10" do not come cheap and the bigger they are the more likely they are to break. Those sizes your getting to the point they have enough mass that every crash will potentially break something major.
5" are robust, 3" and smaller can be extremely robust and through the camera you cannot tell the difference in size. Id suggest looking into one of these for one setup while building a larger second setup. This also let's you put the smaller cheaper one into the air first at any given location before launching a long range rig. I've been doing that for years just to test the area for areas with poor video signal or interference that could bring my expensive rigs down.