Maybe you have a combination of diagonal rod length and delta radius error, possibly with incorrect steps per mm. These errors can lead to z-height error like this (these may be at the same height, depending where you measure ABC and centre):
[attachment 32970 err.png]
If your z-height error is not nicely symmetrical across the 3 axes then position of one of your virtual towers may be wrong too.
For possible remedies look here: [forums.reprap.org]
[attachment 32970 err.png]
If your z-height error is not nicely symmetrical across the 3 axes then position of one of your virtual towers may be wrong too.
For possible remedies look here: [forums.reprap.org]