Some protractors have a tiny dimple in the surface at the point where you want the stylus tip to sit. Catching the stylus in the dimple is typically enough detention to immobilize the arm while you are trying to do alignment, even with a bit of AS in play.
Aligning cart on Rega style arms without defeatable anti-skating?
Rega arms use a magnetic adjustment to apply anti-skate force. It is my understanding that many (most?) Rega arms cannot have their anti-skating completely disabled due to this since at the zero setting, the magnet may not be far enough away to completely be ineffective. This probably varies with manufacturing tolerances.
In my experience, zero anti-skate setting always has a small amount of lateral force applied which is most obvious when trying to balance the tonearm. After applying appropriate VTF it is fine, but I cant help but wonder if the lateral force also being applied makes aligning with a precision protractor a futile exercise.
How does anyone mount a non-Rega cart in a Rega arm?