From Marlin configuration.h

// Horizontal offset of the universal joints on the end effector.
#define DELTA_EFFECTOR_OFFSET 30.0 // mm

The distance from the pivot point of the Rod to the center of the Jgead on the end effector is 30mm.

Do they mean the mid point between the two parallel rods? If so it should me 17.5mm.

This is not proportional but which measurement is correct?

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disneytoy
Do they mean the mid point between the two parallel rods? If so it should me 17.5mm.

Yes, the distance from the effector center to the middle point of the two pairs of u-joints is the right one.

good reference image

My only concern about that diagram, is the DELTA EFFECTOR OFFSET goes from the ro pivot point, to the next axis pivot rod . But wouldn't the Centerline be th absolute center of the effector? I think that drawing is inaccurate.

In the picture it goes from effector center to the middle point of the two pairs of u-joints.

Maybe this will be clearer...

John's 3DR “Simple” Delta Printer Firmware Settings

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disneytoy
My only concern about that diagram, is the DELTA EFFECTOR OFFSET goes from the ro pivot point, to the next axis pivot rod . But wouldn't the Centerline be th absolute center of the effector? I think that drawing is inaccurate.

Remember that the effector base is triangular so it appears off center in the side view...

Very helpful information. Thank you. Will have my arms fiished maybe tomorrow. Getting closer!!!

Quote
ddseeker
Maybe this will be clearer...

John's 3DR “Simple” Delta Printer Firmware Settings