The compasses has been used to find accurately the center of the lens mount protection cap.
Adjusting and aligning very accurately the position of the vertical arm w.r.t. the lower rail:
The pin nail must fit nicely inside the 3/8" threaded hole of the lower rail of NN5.
Below: this was shot just before final aligniment shown above: You may see the necessary magic tool (in red on the pic):
Another "rail" is aligned by using the same means.
Note: That other system produces a much lower Nadir obstruction when screwed on my Slim Rotator. It is by far now my favorite system when a single row of image is not sufficient. Note that alternately, the vertical arm of the NN3 can also be fitted precisely here (see the other hole just next to the knob)...
11 November 2009