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9.1. Over-constraint and conditional locators will produce error messages in Run Log after nominal build or analysis (simulation, sensitivity, geo factor).
9.1.1. 3DCS Mechanical is very rigid about wanting each part constrained by 6 and only 6 DoFs and about using the same pairs of locators restraining the same DoFs for each build.
9.1.2. Conditional logic is available in the moves, but since it doesn't automatically break a previous joint, it can be difficult to use.
9.1.3. This does not mean 3DCS Mechanical can’t be used in models with locators that may fight each other. For example, consider a part with a flange which attaches to a Fixed part by attaching the flange to a flat surface (Planar move) and also with a long pin placed within a long hole (Cylinder move.) Since the Planar move controls 3 DoFs and the Cylinder move controls 4 DoFs, the locators will fight each in one or more DoFs.
9.1.3.1. First, determine which pair of locators will be the master. If the flange has a large overlap to the base part and the hole-pin pair has a generous amount of hole-pin clearance, then the Planar move should be the master and the Cylinder move should subordinate. The move Drop DoF setting, move Type, and/or move features may need to be changed so that only 2 (or 3) DoFs are controlled by the subordinate move. The Point on Line move is probably a good choice for this case.
9.1.3.2. Verify the tolerances are unlikely to switch which pair of locators are master. If the tolerances are likely to switch which pair of locators are master:
9.1.3.2.1. Alert your customers about the inconsistent locators. If possible, have them designate which locators to use.
9.1.3.2.2. Otherwise, model with the “more likely” locators as master. Add an Iteration move loop to switch to the other locators as master when they interfere. If necessary, add another Iteration move loop to switch to “average” locators as master when both sets interfere.