I have built and flown three Ikarus Shockys till they eventually crashed and am busy with a new Ikarus F3a Shocky... I have learnt the hard way with most of the weak points on these shockys... The new ones are better.. I use a AXI 2208/34 outrunner setup and wouldn't fly it with anything less.. This is what I do to a shocky when I build it..
Before I assemble the two pieces of the fuz I cut square inlays into the front of the fus with about 2-3 degrees right a about 1 degree of down thrust for the firewall be glued onto... Then I cut out a round firewall from 3.2 mm 3ply with little grooves for the foam to slide into... Then I cut a piece of stock 10mm balsa and glue it with 30 min epoxy to the back of the firewall to support it.. It fits nice an snugly.. I also reinforce the fus here an there with triangle balsa and epoxy.. And as I posted in another thread, I use carbon fiber pushrods from an old foamy and use it as bracing between the fin and tail plane to make it stiffer, one mod that really increases its flying quality..
I do exactly the same with the new shockys but they are alot more solid... I will post some pics as soon as I finish the one I'm busy with.. won't be too soon as I'm waiting for a replacement servo.(one died during the last crash
)..
Hope I helped..
AL..