Dynamic Mirror
Dynamic Mirror draws the other half for you. Pick a line, turn it on, and draw on one side of the line: as you draw, the mirror image shows on the other side, and when you place a piece its mirrored copy is placed too. Each copy stays tied to its original with a Symmetric relation, so moving or resizing the original moves the copy.
When to Use It
- Drawing a part that is the same on both sides of a center line, such as a bracket, a lever or a plate with matching holes
- Laying out holes or slots in pairs across a part
- Any sketch where you would otherwise draw half and then use Mirror Entities
Step by Step
- Open a sketch and draw the line to mirror about. A construction line is best (Line, then Construction line), since it never cuts. An ordinary single straight line also works.
- Click Mirror on the Sketch tab. The panel opens.
- Click the 2. Mirror about button, then click the line. It turns green.
- Under Dynamic Mirror, click Draw mirrored about the line. The panel closes, the Line tool is picked for you, and a message says Dynamic Mirror is on. The Mirror button stays lit while it is on.
- Draw as usual with any drawing tool. The line stays lit green. With Line, Construction line, Arc, Circle and Rectangle a dashed green copy follows the pointer on the other side while you draw.
- Place the piece. Its mirrored copy is placed at the same moment.
- To stop, click Mirror again and click Stop Dynamic Mirror. The copies made so far stay, still tied to their originals.
Options
- Draw mirrored about the line: starts Dynamic Mirror about the line chosen in step 2 of the panel. With no line chosen, a message says to pick one first.
- Stop Dynamic Mirror: shown in place of the start button while it is on. Ends it.
- Every drawing tool takes part: Line, Construction line, Arc, Circle, Rectangle, and the shape buttons (slots, polygons, center rectangles and the rest). Drawn construction pieces give construction copies.
Tips
- One Undo (Ctrl+Z) takes back a piece and its copy together.
- Change the original, not the copy. The copy is held to the original, so sizes and drags belong on the original.
- A piece that is already its own mirror image is not doubled. A circle centered on the line, a rectangle drawn across it evenly, or a line drawn along it gives no copy.
- A copy that lands exactly on a piece already in the sketch is not made either. A Center Rectangle or a slot centered on the line keeps its own diagonals and sides, without doubles.
- Start an open outline on the line and end it on the line, and the copy closes it into one outline you can cut or extrude. A piece that touches the line is tied point by point (Coincident where it touches, Symmetric points elsewhere) instead of one Symmetric relation; it holds the same way.
- The size box opens on the piece you drew, not on its copy, so a typed size goes to the original and the copy follows.
- Relations added while drawing (Coincident, Horizontal, Vertical and so on) are added to the original only, and never between a piece and its own copy. A piece started on the end of an earlier copy is tied to it like any other piece. The copy is held by its Symmetric tie, which already keeps it a true mirror image.
Limits
- Dynamic Mirror works about one line at a time, in the sketch it was started in. Leaving the sketch turns it off.
- Deleting the line (or taking it back with Undo) turns Dynamic Mirror off, with a message.
- Text, hole places from the Hole tool and part edges brought into the sketch are never mirrored.
- The live dashed preview shows for Line, Construction line, Arc, Circle and Rectangle. The shape buttons and Spline show no dashed copy while you draw; their copy appears when you place them.
- An end you put on the line is joined to the same end of its copy, so the outline stays closed. If you drag that end off the line, both ends move together: the halves stay joined but are no longer exact mirror images at that point. The end is not held on the line unless you snapped it to the line's middle or an end; to keep it there, add a Coincident relation between that end and the line (see Relations).
- Pieces that cannot hold relations (a combined outline) are copied but not tied.
Common Problems
- The message says to choose the line first: click 2. Mirror about in the panel, click a construction line or a single straight line, then click Draw mirrored about the line again.
- The line has no length: the chosen line is a point. Draw a longer line and pick it.
- No copy appeared: the piece is its own mirror image, or it is text, a hole place or a part edge.
- Dynamic Mirror turned itself off: the line was deleted or undone, or you left the sketch. Pick a line and start it again.
- The copy will not take a size: sizes go on the original. Type the size on the original and the copy follows.