As per DH convention, direction of X2 is wrong. It's not perpendicular to Z1. It should be along X1 direction in order to make it perpendicular to both Z1 and Z2.
As per DH frame assignment convention, direction of X(i) should be perpendicular to both Z(i) and Z(i-1).
As per DH convention, direction of X2 is wrong. It's not perpendicular to Z1. It should be along X1 direction in order to make it perpendicular to both Z1 and Z2.
As per DH frame assignment convention, direction of X(i) should be perpendicular to both Z(i) and Z(i-1).