Originally Posted by TheCure
I'd recommend stuffing a 1cm hollow carbon rod about 1/3 from the tip of the nose to about halfway back in the battery area.
if can be done by serrating the rod by dremelling a number of notches a few mm apart around the perimeter. Rotate the shaft like a drill would. Back it out, stick some Gorilla glue + water in the hole, and re-insert the rod. Once set, cut the front protruding rod off.
My PK is super stif and strong now. I have almost no fear of crashing now (I still would rather not).
My way is to lay in two balsa spars underneath ... these not only are light and give rigidity with them and the epoxy, but also allow me to fix the velcro more securely to hold the LiPo in place.