Choosing components for a small drone!

hello everyone i want to build a quadcopter that weights less than 500g and i need help choosing the right components for it. i have a 3d models for the frame that i could print on nylon or pla to be strong and light, it will weight around 60grams and it’s designed for 5 inch prop. from here i know that i need a motor that has a thrust of 250g, use 11.1v and 5 inch prop. i don’t know wich configuration to choose in order to get decent fly speed and best flying time, i can use 3 or 2 prop with higher kv or lower kv with 3 prop but o don’t know what kv i should choose and because of that i can’t choose the esc and battery yet. i know that i can calculate that max discharge rate of the battery by multiplying the Ah by C rate and get for ex 100A but what does this number represent and how much time can i fly with that, also choose bigger C rate or mah ?
also can the drone transmitter interfere with the fpv tx if they are both 2.4ghz but different channels?

Well… going 3s in 2021 is, honestly, like throwing money away. It’s either 4s or 6s. You can print a frame, but you would have to replace everything after any crash. The max current draw determines how much “power potential” a battery has. If it isn’t enough for a specific build, it will not fly good, and it can even blow. For a 5inch build, you want around ~1500mah ±300mah, with about 100C

I don’t know where you found a 2.4ghz vtx, because those are pretty rare. 99.99% of all video transmission on fpv quads is on 5.8ghz

Thanks for reply, so 4s then, i can print replacement frames if it is nedded, i have a lot of pla spools and it is quite strong i think it will resist more time on crashes.
If my instalation require let say 100A and the power potential is gone be bigger that that i am good then, but as i read the bigger mha the more flying time, is best to take the battery at 1500mah and increase the C rating until i get the max height i can support or use 100C and increase mha instead, i want the drone to be able to fly long time
I saw that there exist this kind of 2.4 ghz or 900mhz tx but i don’t know if they are legally in Romania, but my antena of the drone would be 2.4 so i reach the max distance of 1 km and 5.8 reach only 500m, i am wonderig if i can use both together without interfering, i heard about 1,6,11 channels

Even 1.2 Ghz tx

5.8gHz can go 1.5km on 25mw with good equipment, now imagine an 800mw 5.8gHz vtx. No real point in going with exotic frequencies, since receivers for those can be hard to come by. Yes, there are 900mHz radio control links, but those also come at a decent cost. With a normal 2.4gHz radio (like the TX16S) you can go like 1km just fine. Legality in the EU with drones is a bit all over the place, but I don’t suppose you would get into any trouble.

With a 1500mah battery, you could expect like 5, maybe 6 minutes of flying on a light setup, more when just cruising. But with this, it might be harder to get under the 500g limit.

If you need some extra help with choosing parts, I and a couple of friends made a big guide of all parts & equipment that’s needed, can be found here:

If you find some parts you like, most will have their weight listed in the description, so you can add it all up at the end

I got into this hobby because I had a 3D printer and started designing and printing frames in PETG. I spent more time rebuilding than learning to fly. If you are a compentant pilot you may get away with a good few flights but one bad mistake will get you to your printer and another rebuild. Buy a carbon fibre frame and crash as often as you like and learn how to be a pilot.