SKETCHING IN Pro/ENGINEER Part 2
Terminology Constraint: condition defining the geometry of the entity, such as, horizontal, vertical, perpendicular, etc. Weak constraint: shown in gray. Pro/E may delete this constraint at any time without notification. Strong constraint: shown in yellow. Pro/E will notify you that you have given conflicting instructions giving you the power to decide which constraint or dimension you wish to keep. Current constraint: selected constraint, shown in red.
Constraints Weak constraints are added while you sketch.
Constraints cont’d You want all constraints to be strong. If they are strong they will be displayed in yellow. The smart student will make sure all constraints are yellow. Delete constraint Select constraint symbol, press Delete key
Constraints cont’d Constraints made strong, disabled, or toggled between while sketching. Lock constraint Toggle between constraints Hold down the Shift key and right mouse click. Press the tab key to toggle between constraints Disable constraint Sketch Right mouse click Result
Constraints cont’d Add constraint after the entity was sketched or make a weak constraint strong.
Constraints cont’d Add constraints after the entity was sketched cont’d. Before Selected Vertical: Selected Horizontal: Selected center of circles Selected endpoints Selected line
Constraints cont’d Perpendicular Midpoint Equal Parallel lines
Constraints cont’d Tangent Concentric
Resolve Sketch Given: Lines constrained to be perpendicular and one horizontal Crashed when tried to also make the lines parallel (2 lines can’t be parallel and perpendicular at the same time. Undo or Delete the constraint you wish to remove.
Practice Constraints – all except symmetric Try different combinations, such as endpoints, centers of circles and arcs, on the line or edge of circle, etc. Add conflicting constraints and resolve them
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Dimensions Weak dimensions are in gray Pro/E may change these dimensions at any time without notification. Strong dimensions are in yellow Pro/E will notify you if there is a conflict. The value of the dimension may change, but you decide whether to display the dimension or replace it with another dimension or constraint.
Dimensions cont’d To add a strong dimension Select the Dimension icon Select entity(ies) – THINK dimensioning rules! Middle mouse click where dimension is to be placed Select entity Place dimension Place dimension. Notice extension lines overlap object lines. This will cause more work when cleaning up the drawing file. Select entity Select endpoints Place dimension Better
Dimensions cont’d After all dimensions necessary for manufacturing have been made. Gray constraints must be made strong. Select endpoints Place dimension
Dimensions cont’d Single click for radius (180° or less) R will not be displayed in sketch mode, but will in drawing file Double click for diameter (over 180°) will not be displayed in sketch mode, but will in drawing file Single click. Radius – notice arrowhead. Double click. Diameter – notice arrowhead. Click on the circle or arc.
Dimensions cont’d To move dimensions To edit dimensions Select the Select icon, click and drag dimension to new position, release mouse button To edit dimensions Select the Select icon, click on dimension and type in new dimension Modify dimensions Select the Modify Dimension icon Select dimensions to be modified. Edit dimensions, select check mark icon
Customize Select Sketch > Options > Sketcher Preferences Parameter: value in Sketcher, such as, grid spacing, etc.
Practice Think dimensioning rules! Add strong dimensions Move dimensions by dragging them Edit dimensions (double click) or Modify dimensions
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Best Way to Start Draw a circle Edit the dimension to an overall dimension of part Delete the circle