Combining Commands
In drawing your parts you will encounter challenges:
- How can I make a Popsicle stick shape so the end arcs meet the straight lines perfectly?
- How can I place mounting holes equidistant from each corner of a rectangle?
- How can I place two holes evenly spaced between two other holes?
- How can I move a circle so it's tangent to two other circles?
- etc.
Those new to CAD often try painstakingly over and over to carefully position lines with the mouse, zooming in and out to check their results and other ad-hoc methods such as nudging lines incrementally by very small steps (e.g. .001"). These methods get them close to the desired result but left knowing the drawing it not quite right.
There is a better way - one that's fast and gives perfect results. It's called geometric construction. Geometric construction is a technique of combining available commands to solve drawing problems. For example, to draw a Popsicle stick using geometric construction you might combine the rectangle, circle, snap and intersect
commands to get a perfect result in seconds.
The diagrams below give many more examples that help you learn geometric construction. Try several yourself. Many of these techniques are also
demonstrated in the
Video guides.
The diagrams below assume you have learned how to draw, select, move, delete,
stretch, rotate and snap basic lines.
The techniques assume snap is on and grid
is off. Menu commands are shown in blue. Changes are shown in red.
For example,
look at the "Draw a square" diagram below. Read it this way:
- Hold down the Ctrl key on the keyboard.
- Draw a diagonal line.
- Draw a rectangle snapped to the diagonal line.
Correction above for Polygon: Edit Preferences; 2D; Rotation Snap Angle; 360/5;
OK; Edit Copy; Edit Paste; Press R key; Edit Copy; Edit Paste; Moves lines into
position.
