250 size format
very simple 6 part design.
very solid when bolted together.
all electronics and wiring are interior.
battery can be mounted above or below (hence the name) while the unused mounting point can be used for a action cam.
mounting point for a Eachine tx02 AIO fpv cam (tx01 & tx03 also fit)
will take upto 2205 motors.
can accomodate 4x esc or 4in1 esc

bolts used :-
http://www.banggood.com/240pcs-M3-DIN912-Hex-Socket-Head-Cap-Screw-Nut-Assorted-Kits-4-25mm-p-1074609.html?rmmds=myorder

this design has only seen light flight usage and limited airtime, for a bit more chunkier build and interior space also see my ViceVersa XL/V2 design which immediately followed this design and is better spec'ed to handle more electronics with increased protection, it also takes upto 24xx sized motors
https://www.thingiverse.com/thing:2218741
my own see's regular flight time on a near daily basis (weather allowing) and performs excellently in both terms of heavy acro flying and high speed maneuverability while not sacrificing durability.
https://www.dropbox.com/s/48k7wvf8r5jo6f4/2017-06-09%2021.49.30.jpg?dl=0

poltur XL

No

No

0.3

30%

though the arms are very resilient when done in ABS (havnt tried PLA,Petg etc) they'd definitely benefit further from a light acetone vaping session if you have the time or capability