You may want to make three accurate templates pattern
A stable material like 1/2" thick Birch ply or 5/8 Flooring
plywood will be OK.
Make one template for the 2 ft station away from the root
one at the first taper break and the third near the tip.
use the top surface of the template as a reference
to measure your angle deviation.
your measuring device should be accurate to within 1/4 degree
over 2 ft. make sure to position the templates in the same
relative position on the other wing when measuring it.
Always point the measuring device in the same relative direction.

You need to print out the airfoil with the correct chord dimension
for each station. The Ventus has a different tip airfoil, you must
find out what airfoil it is.
You can see a sample picture on my web page under personal
http://www.wingdolly.reach.net/personal.html
All this assumes you checked your aileron and flap settings.
Even if the aileron is set right, if the flap is off by 11/2 degree you will
have that effect.
Regard
Udo