This can happen if the BASE UNIT SYSTEM in which the model was original created, and the BASE UNIT SYSTEM in which it is subsequently edited are not the same. For example, if you created it when the BASE UNIT SYSTEM was set to Metric, and then made changes to the model when the BASE UNIT SYSTEM is English, the joint coordinates will undergo minor changes due to rounding off.
The best practice is to ensure that the BASE UNIT SYSTEM is consistent with the units in which data is specified in your model. So, if you coordinates are in MMS, set the BASE UNIT SYSTEM to Metric before you start creating or editing the model. If the coordinates are in FEET or INCHES, set the BASE UNIT SYSTEM to English.
You can find some useful information on the BASE UNIT SYSTEM in section 1.3 of Tutorial 1 in the Getting Started and Tutorials manual under the heading "Note about the unit system".
The best practice is to ensure that the BASE UNIT SYSTEM is consistent with the units in which data is specified in your model. So, if you coordinates are in MMS, set the BASE UNIT SYSTEM to Metric before you start creating or editing the model. If the coordinates are in FEET or INCHES, set the BASE UNIT SYSTEM to English.
You can find some useful information on the BASE UNIT SYSTEM in section 1.3 of Tutorial 1 in the Getting Started and Tutorials manual under the heading "Note about the unit system".
