Arm mounted vs body mounted ESCs: Advantages and disadvantages

[Thomas]

Hi
I am currently putting together a build and have the option of mounting the ESCs either next to the motors on the ends of the arms, or within the the body of the multirotor in a deck below the flight controller other electronics . I';m just wondering what the main advantages and disadvantages of each approach are. This is what I';m guessing so far:

Arm mounted
Advantages:
Saves space in the drone body (ESC and wiring)
Good ventilation
Easy to fit / replace

Disadvantages:
Exposed in a crash
Difficult to weather proof
Moves weight away from the drones centre of gravity
May look a bit naff (matter of opinion)

Body mounted
Advantages:
Better Aesthetically
Improved weight distibution
More weather / damage proof

Disadvantages:
Takes up lots of space
Poorer thermal performance
Bugger to get to

I';m wondering to what extent each of these are true, and which are in practice are the most important (also there may be other things I haven';t considered. In my case, I have multiple decks, so space is not necessarily the biggest issue (though heat build up may be with 8 x 4114/320KV motors). I';m also a bit picky about the look of the build  , so I';m leaning towards body mounted.

I';d be interested to hear peoples thoughts.

Thomas

[Gaza07]

Hi Thomas here';s a little more food for thought when arm mounted they will be cooler because of the prop wash,
also when arm mounted they cannot affect the compass chip as they might do if sat directly under it, although Im not sure they will ive not seen any proof they do, most but not all of my quads have the esc';s mounted on the arms and Ive never busted a esc in any of the crashes Ive had but I suppose that could easily change 

[Thomas]

Yep. Overheating is a big concern. Though I will have room, it is still going to be pretty tight. I';ll have a couple of lipos below and all the electronics in the deck above. Hmmm....
Cheers Gaza

[Gaza07]

I think quite a few people mount them on the main frame and have no problems it may just boil down to personal choice 

[teslahed]

I mount mine on the arms. I';ve never damaged one in a crash except when a motor came loose and pulled the ESC with it.

Personally i think the improved ventilation is the biggest factor - that';s why i put mine on the arms instead of the body. I haven';t found the weight distribution to be an issue - partly because i try to use fairly light ESCs and save weight by using shorter wires.

[Flyinegypt]

Another reason for body or near body mounting.
It is fairly well known that one should keep the length of battery to ESC leads as short as possible to avoid switching noise. Even more so when the battery is feeding multiple motors. The individual ESC to motor leads can be lengthened and not cause so much of an issue. This from my fixed wing experience.

[Jumpy07]

Other reason for mounting them on the arms.. is to get the RF noise away from the FC and any FPV gear..

[Thomas]

Thanks for all of the comments. It seems like this is a bit of a marmite subject. I may go with the internally mounted setup on the basis it looks a bit cleaner (probably the worst selection criteria to go with though).
Cheers
Thomas