Hello GW,

Some models already have a firewall that povides yaw thrutst angle and down (pitch) thrust angle.

Many models do not have such angled thrust.

It is quite common to use washers (shims) to adjust such angles if and as desired.

Different methods are used to measure these angles.
Some commercially available devices are available on the market.

One method that can be used at home (workshop) is to verify that the leading edge of the wings is square ( 90 degrees) with the longitudinal axis and measure from the prop tips to the leading edge. A simple calculation gives us the angle of side thrust.

A similar methos can measure the downthrust angle (or up thrust) by placing the longitudinal axis horizontal and making measurements from a known square perpendicular to the horizontal.

These angles are not critical and it will not be obvious if there is an appreciable error from any specifications. They are a compromise anyway.and would stand true for only one flight condition which would be a straight and level flight at a specificspeed..

Zor