I have now finished all the sub-assemblies of my Cularis, so before sticking the fuselage together, I decided to do a trial balance to check on the COG. Here it is, poised on the wing dimples. The airframe, with installed servos, but not motor, battery etc. weighs 1.1kg including the two steel balls located in the tail section.
In the photo below, you can see the Pentax A30 camera mounted down in the cockpit area which I expanded to a width of 60mm by machining out 6mm from each side wall. I then stuck the perspex side panels with thick CA as recommended to increase
rigidity. The large nut and bolt weighs a little more than the Pico-Pilot NA which have now bought second hand. There is a 3P 2500mAH LiPo battery pushed up under the wing root with the stock Multiplex motor, ESC and spinner up front and a Multiplex dual conversion 7 channel Rx.
The real trick that made this all work was moving the elevator and aileron servos to the rear. Because of the 4:1 leverage, some 35gm of servos is now balancing 140gm of camera. It needs some careful work to machine out the interior of
the tail section to mount the servo, but the result is worth it. I will post more details of my modifications in the Cularis building thread on rcgroups.
Building a UAV for phot mapping - Previous Posts