I have used the little Wing Wing Z-84 for nearly one year with a Pixracer FC and Arduplane with a lot of fun, except not liking the high noise level due to pusher configuration. WW Z-84 with 3s3500 mAh LiIon & Pixracer:
After we (my colleague @walter and me) built a tri-tilt-vtol ("Mozart": https://vimeo.com/231290387 ) and a vectored-tail-sitter ("Belly": https://vimeo.com/235059739 ) we were very excited about the almost inaudible noise in plane modes of those "twins".
So we are trying to convert the pusher Z-84 into a tractor twin engine - of course with ardupilot tailsitter VTOL functions:
Like Greg Covey's great Z-84-QuadPlane Project ( https://discuss.ardupilot.org/t/wing-wing-z-84-quadplane-conversion/22097 ) it will be also a fun project using components lying around here anyway:
We are also using the AX 1806N 2100kv Brushless Micro Motor (19g) https://hobbyking.com/en_us/ax-1806n-2100kv-brushless-micro-motor-19g.html
and 12A ESCs https://hobbyking.com/en_us/turnigy-plush-12amp-2a-bec-besc.html
with CW/CCW 6x4 Props and 3s2200 mAh Lipo .
The wooden gondolas are simply hot-glued to the wings:
and houses the esc*s
At rear, where the motor was former located, a small amount of material has to be removed to allow the 3s 2200 mAh battery to be inserted
The pixracer is mounted in front with direction to the right, because this direction allows the USb plug and the SD card to be easily accessed from the front. The frsky Rx is mounted on the left side of the battery, also conntected with the telemtry port of the pixracer.
The power module is located between the battery and the controller
Safety switch and M8N GPS are mounted on the hood.
The CoG in the vertical axis is also where it should be - only luck.
Unfortunately due to the the bad weather forecast for central europe, it will take a while until we will dare the first flight...