Hi all, I'm just trying to do the layout of components in the fuselage of my homebuilt flying wing to get the C of G correct.

At the moment the battery and ESC are getting pretty close together, and ideally as far as C of G is concerned they'd be nearly sitting in top of one another. Is this something to be avoided at all costs?

The ESC will be sitting on the surface, should I don't imagine any temp problems with it, but battery will be buried a little deeper down in the foam. Is it likely to get quite hot as well?

So long as you've got a decent cooling airflow, it doesn't matter if battery and ESC are very close together. What you should try to avoid, especially if you're not on 2.4GHz, is having the receiver and any of it's related electronics (servos, servo wires, antenna) close to the battery, ESC, motor, and their heavy-duty connecting wires.

So the ESC should have good cooling airflow, but I wouldn't say the same for the battery - it will be buried under a hatch.

The receiver and servos will be fairly distant, and I am running 2.4ghz.

So long as you're using a battery that's more-than-adequately specified for the amps you're drawing, I wouldn't worry too much about its cooling. None of mine have any special air cooling, and some of them are in fact surrounded by foam, but they barely get warm because they're operating well under their theoretical Ah x C amps capability.

Yeah I'm pretty sure I'm not going to break the 25C
Motor will draw around 20 amps top, plus another couple for the servos etc.

Thanks for that, I will probably sit the battery and ESC on top of one another to an extent.