OK "flexible/TPU" if they don't know what that is I'll hire a proffessional.

I was about to pull the trigger on the FC linked above but decided I have to research the hole spacing conundrum, it used to be 20x20 or 30x30 for FC's. I read somewhere that FC's are starting to come out with 25mm spacing and that was supposedly a good thing because Walksnail, HDZero, and DJI all have 25x25. The Carnage frame has holes for both 20 and 25 with I guess the FC mounted to the bottom and the VTX mounted to the top. So is there any real advantage to buying a 25x25 hole spacing FC? Should I care?

25x25 FC's tend to be AIO FC's (where the ESC is built into the FC). There are pros and cons of that in that if you manage to fry an ESC you have to replace the whole AIO board, but on the plus side everything is on a single board so it's more lightweight than a 2-stack FC/ESC setup and it can be fitted into smaller quads or ones with limited space between the top and bottom plates. For large high powered quads my advice is to use a proper 2-stack FC/ESC setup which come with either 20x20 or 30x30 mounting holes. The ESCs on those tend to be much more resilient because the manufacturers have the required real estate on the board to use larger MOSFETs which can handle more current, and the larger single purpose ESC board can also dissipate more heat. If you do manage to fry an ESC on one of those you only need to replace the ESC board and not the FC board. So the choice is yours

OK hole spacing AND configuration need to be considered. Thanks for your insight. Is a 3.5" 250g quad considered a "large high powered quad" nowadays?
Flywoo GOKU GN F745 EVO HD 2-6S 20x20 AIO Flight Controller w/ 40A 32Bit 4in1 ESC
BROTHERHOBBY VY 1504.5 3950KV MOTOR
I ordered the frame with 25mm spacers so I have plenty of room to work with.

fwiw if you wanna go the 25mm AIO route:

Flywoo GOKU GN745 F7 40A 2-6S BLHeli32 AIO Flight Controller
https://www.getfpv.com/flywoo-goku-gn745...oller.html

Confess I like Flywoo stuff but not quite a fanboy... but like SnowLeopard said, you have choices.

I prefer the 20x20 GOKU you listed earlier. It's perfect for this AIO solution.. This one is designed to mount at 45 degrees. There are so many choices, I looked up Bardwell's list. I could get a IFLIGHT BLITZ AIO F745 FC / 45A ESC for less but it uses BLheli_S. For a stack the FOXEER F722 V4 & V4 PRO MINI FC
FOXEER REAPER F4 45A / 60A MINI ESC combo is available but that is a F722.

Screw it, I got the GOKU AIO you listed earlier @skywanderer. It is cool and totally current. I hope it lasts but generally I'm a pretty mellow flyer.

Added: Do all "whoop" style boards have 25.5x25.5 hole spacing designed to be mounted at 45 degrees? I seems like larger traditional frame quads use 20x20 or 30X30 boards at 90 degrees. Is this size of quad (3.5" props) a kind of a crossover realm where people are using whoop or traditional board styles?
The one I ordered is an odd shape, longer along the flight axis. Hopefully the extra real estate is good for components layout and durability. I was a bit concerned that a traditional stack AIO, Rx, and the Walksnail VTX would not fit under the hood, or come out over 250g. This way I know that won't happen.

(06-Dec-2023, 12:26 AM)skywanderer Wrote: Some tasty 3.5" ingredients:

V2 Carnage 3.5"
https://www.cncdrones.com/v2-carnage-35.html

Flywoo GOKU GN F745 EVO HD 2-6S 20x20 AIO Flight Controller w/ 40A 32Bit 4in1 ESC
https://www.racedayquads.com/collections...t-4in1-esc

BROTHERHOBBY VY 1504.5 3950KV MOTOR
https://pyrodrone.com/products/brotherho...50kv-motor

...will get you started.

(10-Dec-2023, 05:53 AM)husafreak Wrote: Screw it, I got the GOKU AIO you listed earlier @skywanderer. It is cool and totally current. I hope it lasts but generally I'm a pretty mellow flyer.

Added: Do all "whoop" style boards have 25.5x25.5 hole spacing designed to be mounted at 45 degrees? I seems like larger traditional frame quads use 20x20 or 30X30 boards at 90 degrees. Is this size of quad (3.5" props) a kind of a crossover realm where people are using whoop or traditional board styles?
The one I ordered is an odd shape, longer along the flight axis. Hopefully the extra real estate is good for components layout and durability. I was a bit concerned that a traditional stack AIO, Rx, and the Walksnail VTX would not fit under the hood, or come out over 250g. This way I know that won't happen.

  I have a build thread on the forum with some pictures of the Carnage V2.
 BH 1504.5 3960 are a great match and I have tried several 3.5” props and keep going back to Gemfan Hurricane 3520.
  There’s other good props but I got the best combo of efficiency and power out of the Gemfan 3520  triblades.
 Whoop boards can be mounted square but you will need to make a few minor changes in betaflight.
  It’s a great frame and durable by design and still one of the lightest 3.5” frames.
  My thread has my weights.
There’s a lot of build threads of the carnage with pictures on rotorbuilds.com.

Thanks! I will search for your thread and also rotorbuilds.com I got the frame and the motors. Everything else is coming today. I got TPU and a friend printed the camera and antenna mount but he said the prints turned out poorly, stringy and weird but probably useable. He is going to try and figure out the correct settings and try again, he has never used TPU before.
It is cool how the frame uses 3 posts to save weight. And as soon as I saw it I could see how it will work with my HD VTX bolted to the top plate and the FC (AIO in my case) to the bottom. I'm not sure what is the best way to attach the Rx, double sided tape to the FC probably.
Cheers!

Oh yeah, I was a bit worried about the Brother Hobbies motors, I have them on some old builds and they are extremely "coggy". But these new ones are smooth as silk

fwiw, If you find yourself gravitating towards this size kward, just saw this:

Bitty Banger - colored plate bling if wished...
https://www.cncdrones.com/35-banger.html

T-motor 1604

...read the “Designer notes” about it on cncdrones...

Can't wait to hear your thoughts on the Carnage tho...

That looks a lot like the Carnage doesn't it? Good notes! It sounds like your suggestions for me were spot on too, many thanks!