Cartridge protractor- the best?

Anything that doesn't have a nail point that rests on the pivot point is useless as far as precise alignment is concerned. Buy the Feickert . The Geo disc is a joke for precise alignment.

Can someone please explain how any of these alignment protractors being discussed that use line of sight from spindle to pivot can be as accurate as a protractor that uses an arm and pin/nail (Dr. Feikert or Clearaudio) that locks the protractor to the arm's pivot point ? Seems to me using line of sight, it would be easy to be off by a few millimeter's either way, resulting in an inaccurate cart alignment.

Hi Nandric...so using a feikert as an example, the arm that touches the pivot point is only for getting the correct spindle to pivot point distance and has nothing to do with adjusting the zenith (offset) angle ? In other words, as long as the protractor is on the spidle, no matter where the platter moves, the null point alignment lines will be correct ? This now makes sense to me...duh

If this is the case, I need to get that mirrored protractor to better see my cantilever which is shorter than normal along with being a low riding cart that makes it very difficult to see the cantilever head on with the needle down on a traditional protractor.

In other words, as long as the protractor is on the spidle, no matter where the platter moves, the null point alignment lines will be correct ? This now makes sense to me...duh

actually on further thought, this doesn't make sense to me...The line of sight line on the protractor used to align the protractor to the pivot point seems prone to error. What am I missing ? TIA

The convenience comes from the ability to firm lock the platter/alignment tool in a single spot when making the tangency adjustment.

Thanks for clearing that up for me Larry.