Did some trimming of my two new F1D models yesterday. The first one flew
practically "off the board", had to reduce decalage a bit off the
settings I had found with short test hops at the workshop. The second
one gave more problems, at launch torque (~15 to 17 g*cm) the wing
twisted a lot, requiring lots of extra decalage to prevent a dive-in. I
tried to figure out the source of the twist, as these two models should
be similar, built at the same time from same materials, and weighting
the same. While holding the model with a wound motor, there seems to be
a considerable amount of twist in the motor tube. It could be that the
wing struts also bend, increasing the warps under flight loads, I'll
have to try to stiffen them. But it seems that also the tube is
twisting. So:
- can it be that two pieces of balsa, from same batch and similar in
weight, have such a huge difference in stiffness?
- how can the tube be stiffened? Spirally wound boron/carbon/kevlar to
increase twisting stiffness?
Thx,
-Tapio-
Received on Sat Aug 22 2009 - 21:21:54 CEST
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:45 CET