The Shrinking Corridor After a Scale Change
A junior drafter is laying out an accessible corridor in a floor plan drawn at 1:50 in model space. The clear corridor width must be at least 1500 mm. She draws two parallel lines 1500 mm apart, then uses STRETCH to move one wall line outward by 300 mm to create an alcove. After the STRETCH, she runs DIST and measures 1500 mm between the lines. She also notices that the dimension she placed earlier now reads 1800 mm, yet the geometry still measures 1500 mm. She has DIMASSOC set to 2 and the dimension was created by selecting the two lines. A colleague suggests she simply override the dimension text to 1500 and move on. The drawing is due for consultant review in two hours.
1. Explain why the measured distance and the dimension text disagree, and what the drafter should verify first.
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The dimension is associative (DIMASSOC = 2), so it stores references to the two lines and recomputes when they change. A 300 mm STRETCH that moves only one line should update the text to 1800 mm, which matches the dimension. The 1500 mm DIST result means the geometry did not actually move as intended, so the discrepancy is between the geometry and the drafter's belief about it, not a dimension bug.
She should first select the dimension and check which objects are highlighted as its definition points, and use the LIST command on each line to compare their X or Y coordinates. Likely causes: the STRETCH crossing window missed the endpoint (only part of the line was in the selection), the line was locked on a layer, or OSNAP snapped the moved endpoint back onto the original position. Only after confirming the true coordinates should she decide whether to move the line or correct the dimension.
2. Evaluate the colleague's suggestion to override the dimension text, and state the correct course of action.
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Overriding the text to 1500 mm would make the annotation agree with the current geometry but would hide the fact that the alcove was never created. It also breaks the associative link's usefulness: future edits would move the geometry while the overridden text stays fixed, producing a drawing that silently lies. On an accessibility dimension this is a liability issue, not a cosmetic one.
The correct action is to fix the geometry so the clear width is genuinely 1800 mm (or whatever the design requires), then let the associative dimension update itself. If the design intent was a 1500 mm corridor plus a 300 mm alcove, the wall line must be moved 300 mm and the dimension verified with DIST afterward. Text overrides should be reserved for cases where the measured value is intentionally non-graphical, and should be documented.