Olivier, First question: If I understand you correctly, the best way to get a total length of all 9 segments is to create a so-called Analysis Feature for each of them, then create a Parameter which is equal to the sum of all 9 lengths recorded in these Analysis Features. So, assuming each of your wire segments is created by sweeping a circular section along a Datum Curve arc, start with one by selecting Analysis/Measure/Length, select the Curve, then pick Feature from the drop-down list (default Quick). This will create a feature in your model tree called ANALYSIS_LENGTH_1 containing within it a parameter called LENGTH with the length value you want. You can rename the feature and parameter to make them easier to deal with if you want. After doing this for all 9 segments, create a Parameter with a name like TOTAL, then create a Relation like the following: TOTAL=LENGTH:FID_ANALYSIS_LENGTH_1 + LENGTH:FID_ANALYSIS_LENGTH_2 + ... Note the special syntax required, which can be confusing, namely :FID_ . FID stands for Feature ID. If I were you, I would shorten the names of the Analysis Features before creating the summing relation. Second question: To get one of the Axes you want, create a Datum Point at the Center of one of the curves, then create the Datum Axis through that Point Normal to the Plane of the curve. David
