About me
born 1976, M.E. in media tech, living in Leipzig (Germany)
early photography and model plane involvement, first contact with the mikrokopter project in late 2007.
Project MikroKopter X8 "The Oggdo Egg" ;-) (Working Title)
Forum Thread: http://forum.mikrokopter.de/topic-18630.html
After 3 years and several copters I built myself or together with ligi (my +4, the Oktopussy (U8), a dodeka (H12) and a quick & dirty V8) it was time for a little more sophisticated copter. For reasons of redundancy and increased payload I chose it to be an octocopter. The result is a X8 which had its outdoor maiden flight a few days ago in late august 2010. First thing to do were some range tests on the ground for RC connection (~400 m) and Wi.232 telemetry (~ 350 m) followed by some first emptied lipos. I'm quite satisfied so far as it is without extensive adjusting which I will do anyway to maximize handling and performance.
Incidentally it passed the redundancy test: I lost a nut on one of the lower propeller hubs which was apparently not tightened enough and lost a propeller. The change in flight behaviour and handling was barely noticeable, just a tiny bit of drift and a sudden change in sound.
The name 'Oggdo Egg' is just a working title that springs to mind if you see it the first time, and it refers to the way "octo" is pronounced around here where I live (Saxony, Germany). An octocopter would be an "oggdogobbdor" as i was told by a passer-by
Tech. Specs
FC ME with altitude sensor and extra recom
NC 1.1, MK-GPS, MK3mag (from my old quadro)
8x BL 12 (red) in octo distribution board (complete plastic spray isolation)
8x MK 2832/35 brushless motors with EPP1045 props (coax) with 4S lipo
frame: X8 with standard MK centerplates, 15 mm Al profile, 600 mm axial distance
weight: empty 1023gr, with 1x 4S lipo 1250-1350 gr, with 2x 4S Lipo 1550-1670 gr
Lipos: 4S with 2150-2650 mAh single or in pairs
hover current: 16-22 A
RC: ACT DSL-4top 35 MHz, Graupner MC-16/20 (8 ch, soon to be replaced))
Telemetry: BT & Wi.232, DUBwise or kopter tool
While the X shape was initially chosen for a better camera field of view to the front and a more compact design, it proved to be very nice in both handling and visually. I really like it more than the + by now. Probably going to modify my quad to X too (for fpv).
The Styro egg 'helmet', which is actually a deco article from an art supplies shop, looks quite massive but is just 16gr and very stable, almost like a very lightweight bicycle helmet. I managed to destroy only 2 of these (in round form) over the past 3 years. The large asymmetrical outline is recognizable even further away, supported by red and green LEDs sideways and white ones below.
Compared with earlier projects the X8 looks very 'tidy', there are almost no visible cables thanks to the Okto distribution board and I put more thought into a better way of wiring.
The FC is pluggable over a 10p flat cable for all connections, except for power (I²C, beeper, PPM, ACT DSL) so it can be removed / attached in seconds.
I plan to use parallel pairs of identical 4S lipos of the same age and cycle life for more maximum current and capacity, first tests were successful.
Some recycled things were used in the construction: the bottom of a pringles chips can (as the 45° FC adaptor for the X, see pic above), some ancient cables out of 70's computers (lightweight and twisted, perfect for inside the arms for LEDs or beeper), and some carbon scraps as 45° adaptors for the landing gear.
A very first outdoor video:
To Do:
un-improvise antenna setup
new landing gear (too low for cam holder)
more extensive flight testing
payload test