Baseline Dimensions
Measure many points from one baseline, with the dimensions stacked neatly one above the next. A baseline dimension is the distance across, or up, from a chosen baseline to another point. Shop drawings often give a row of hole or step positions this way, every one from the same edge, so the sizes never add up errors.
When to Use It
- Give the holes in a plate as a stack of sizes, all from one edge
- Size a stepped outline from one datum
- Keep a row of points tied to one baseline, so moving the baseline moves them all
Step by Step
- Open a sketch (see Planes and Faces). Sketching is part of modeling, which comes with the Pro plans.
- On the Sketch tab, click Advanced, then Baseline.
- Choose what to measure in Measure: Horizontal (across) gives each point its distance across the screen, Vertical (up) its distance up the screen, and Both one of each.
- Pick the baseline. Press Sketch origin to measure from the origin of the sketch. Or click a point: an end, a corner, a centre, the middle of a side, or a point. Or click a straight edge that runs straight up the screen (the points are then measured across) or straight across it (measured up). The baseline shows as a large dot. An edge is measured from its middle point.
- Click each point to dimension. Each click adds the dimensions at the size the sketch has now, so nothing moves. The shortest sits nearest the sketch and each longer one is stacked above it (or to its right, for vertical ones) at an even spacing, so no two lines cross.
- Click a number to type a new size. The point moves to that distance from the baseline and the sketch solver keeps the other relations true. The box can also switch a dimension to Aligned, or to a reference dimension.
- Press Pick the baseline to start a new stack from another point or edge. Press Done (or Esc) when finished; the dimensions stay.
Options
- Measure: Horizontal (across), Vertical (up) or Both. A straight edge sets its own way and ignores this choice.
- Sketch origin: use the origin of the sketch as the baseline.
- Pick the baseline: choose another baseline.
- Done: close the panel. The dimensions stay.
Things to Know
- Baseline dimensions are ordinary driving dimensions. They are saved with the sketch, come back when you open it again, are listed in Edit, Relations as Horizontal distance or Vertical distance, can be named and used in Equations, and one Undo takes back each click.
- The stack order follows the sizes. If you change a number so that it becomes longer than the one above, the lines swap places by themselves.
- Clicking the same baseline again continues its stack. A different baseline starts a new one.
- A point keeps the side it is on. If it is left of the baseline, typing a new size keeps it on the left.
- If the sketch already sets that distance, the new dimension would over define the sketch. It is added as a reference dimension instead: grey, in brackets, showing the size without controlling it. See Reference Dimensions.
- Ordinate Dimensions do the same job with short lines in one row instead of a stack.
Problems
- "That point is in line with the baseline": the distance would be zero, so it is not added. Use a Vertical Points or Horizontal Points relation to hold it so.
- "That edge is slanted": only a point, or an edge that runs straight across or straight up, can be the baseline. Click one of its ends instead.
- "This baseline already has 60 horizontal dimensions" (or vertical): one stack holds up to 60 in each way. Start another baseline from a different point. Switching a dimension to the other way in its box is refused for the same reason.
- "That point already has this horizontal dimension from the baseline" (or vertical): the same dimension on the same point is refused.
- "A baseline dimension is measured across or up, so it cannot be Aligned": the box of a baseline dimension can switch it between Horizontal and Vertical only. For an edge baseline the way is fixed, so it keeps it.
- "An edge can only be the baseline": after the baseline is set, click points, not edges. Press Pick the baseline to change it.
Limits
- The numbers are drawn level with the screen. Each stack stands just past the farthest of its points and the spacing follows the zoom.
- An edge is measured from its middle point, so it should stay straight. If you later tilt the edge, the dimension still measures from that middle point.
- An older version of the program opens these as plain horizontal and vertical distances, with the same sizes.