The angles change with changing printer delta radius and diagonal rod length.Quote
plastik
What angle should the rods have when the nozzle is all the way to the edge of the printing bed? Is it 20 degrees?
Do not try to measure them. It is hard to do it precisely. It is easier to measure distances.
The only thing why you need them is to get ball joints with enough free angular movement.
When delta radius == diagonal rod then the required free movement:
* around ball joint axe is 0 .. 90°
* in the direction perpendicular to it, it is -30° .. +30°
In most cases, the diagonal rod is a bit longer than delta radius. In those cases, the angular free movement does not need to be as big as indicated above.