For good sound the needle has to fit parallel into the record groove. Othrewise the sound isn't leveled between left and right channel.

Therefore templates are available to buy or to print. They got orthogonal lines on the area where the needle is setting in and where it is setting off.

The needle should be parallel to the lines on the template at R120,9 mm. If not, the screws shown in step 3 can be loosened and the cartridge can be adjusted. After adjusting tight the screws up again.