As a newbie.......... :oops:
Just wondering what you guys do to reinforce your glider wings ....
If you fit a carbon fiber spar how long it is and what diameter ...
do you use a flat or round spar...
where about in the wing do you fit it ...
Regards Sean
I think the answer to that would have to be "It depends...."
It's very difficult to give a general answer.
Why are you reinforcing the wing? Is it a repair, to handle extra power due to your new power system or are you trying to make it crash proof?
Crash proofness is pretty much impossible to achieve with anything but very small planes or by making the plane from flexible material (typically EPP). Often the extra weight and stiffness added by reinforcements has the opposite of the planned effect and just makes the plane more likely to break. Weight can also make it harder to fly so a crash is more likely too!
For a wing with a single spar, that spar will normally be at or near the thickest part of the wing to maximise the stiffness it provides. This also puts it near the point on the wing chord (an imaginary line from the leading edge to trailing edge) where the result of the combined aerodynamic forces appears to act which means aerodynamic loads in flight are less likely to cause twisting of the wing around the spar.
The length will depend entirly on the purpose and the wing you're adding the spar to.
A tube provides torsional stiffness (resistance to twisting) as well as resisting bending loads. A strip positioned vertically will be good for preventing vertical bending (which is what you get from lift) but not very good for bending forward and back or torsion. If these aren't needed because it's already stiff enough then a strip is a good option.
Aidan
