Composite wing spars

Following the article about the vertical spars, another way to make spars in foam wings is to use UD fibreglass or carbone.

Can be used on their own, top and bottom, with different layers etc, but also be combined with the vertical spar, to create an even stronger T or I spar.

Once again, this is the way I do it, but the interweb is full of other methods to achieve the same results. As usual, pictures are worth a thusand words!

On your wing core, trace with a pen the middle line of your spar location :

This is what we try to achieve...

And done!  bit of light filler might be needed, but if you did your grrove correctly, should not be much :) Then, the usual, with the sheeting starting with the upper side of your wing etc...

Of course, same apply if you want to put a spar in the other side of the wing!

Adjust the thickness of the groove depending of the number of layers of material you are using (ie 2 layers of UD carbone from root to ailerons, then 1 layer to the tips...), just update your sanding block with the required thickness.

Below, same, but combined with vertical spars on the wing.