For J4:
- when floor mount -> J3 = 0 deg
- when +90 deg mount -> J3 = 90 deg
- when 30 deg mopunt -> use the method: J3 = +30 or -30 deg, depends what you mean "30 deg to the floor" -> J3 arm perpendicular to the floor
For J5/J6 try using the same method - look at pictures in manual and try to achieve the same attitude to the floor.
thank you!