Hello, i am close to my first build and i wonder wich fc and esc to choose. I have checked 2 4in1 escs. The first is Racestar 4in1 30A with bec and the other is Racestar 35 A without bec.
One guy told to choose  30 A with bec and for fc Matek F405 OSD. So i have to give the 5v bec to feed the fc but this way i don't have 12v for vtx. If i use Vtx with 5V input will all be ok? or will need pdb?
And for the 35A without bec any advice for fc pick and the wiring with it?

It depends. Some VTXs work with 5V and some want at least 7V as they have an onboard BEC to supply 5V to a camera.

I don't recommend 4-in-1 ESCs for people making their first build. If you're also learning to fly, forgetting to disarm when you crash can easily blow up an ESC if the flight controller is trying to spin the propellers but they are prevented from turning.

Blowing up one ESC when you have a 4-in-1 is the same as blowing up all four. It's much more expensive and time consuming to swap out a damaged 4-in-1 ESC than it is to just swap out a single ESC.

Depends on the VTX, most newer stuff has a wider voltage range than the FPV components working only on 12v, like they used to. If the VTX will operate on 5v then it will be fine. Power (W) is the result of multiplying Voltage and amperage, so if you use 5v or 12v you will draw more or less amps to provide the required power to the VTX, performance should remain the same.

If you use the 35A without BEC then you will need either a PDB or an AIO FC with PDB/BEC. There are MANY AIO FC's available now...

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If this was a verbal response I would be saying JINX!

Hello and welcome, toubas!

I am still really new at this, but hopefully I am able to pass along information that might save you some heartache.

When first deciding to build my own aircraft, I stumbled upon a YouTube tutorial that helped a lot.  While I varied some in the parts selection, the wiring stayed the same.



That parts list is starting to become less desirable as it ages, but that can (and has) been built as a first by many people and it is a valid machine.

Fast forward to today, and if I were going to choose a great build tutorial, it would be this:

https://oscarliang.com/build-racing-dron...uadcopter/

There are likely endless combinations of FC/ESC configurations and you could get a lot of varied answers.  My current build is an AIO (DYS F4 Pro "Upgrade" V2) and 4 separate Speeix 30A ESC's on the arms.  Choosing this route, there is only one level of board and I could likely get away with 15mm standoffs if the camera were not so tall.

As for the VTX, my current is a TBS Unify Pro that runs off BAT+.  If you pick one like the Eachine VTX-03, you will just need 5vdc.

Thanks each one of you for the advises.. i will reconsider make a build with seperate escs. Thanks a lot!!

I really believed the the 4-in-1 would be less work on assembly, but when building my latest craft with separates it was not at all more difficult. It also feels like it will be easier to upgrade to higher amperage ESC's later if the need arises.

I would get the one with the BEC just in case you want to power another thing on your quad like a camera or VTx. You should get an Omnibus FC AIO so that you can run it off of 3 or 4 s.