Most AutoCAD users have never typed this command, because the Properties palette does most of what it does. But the change command in AutoCAD can do one thing the Properties palette cannot: bring the ends of many lines to exactly one point with a single pick. When tidying old drawings, that saves a great deal of time.
This article works through five examples, each with coordinates before and after. For the whole editing toolkit, the Institute runs an AutoCAD course for construction.
The -CH alias: CH is not CHANGE
This needs saying first, because it causes the most confusion.
Reading the 2027 alias file acad.pgp directly shows two lines side by side.
| Type | Opens |
|---|---|
CH | PROPERTIES, the Properties palette |
-CH | CHANGE, the command this article covers |
So typing CH opens the Properties palette, not CHANGE. To start CHANGE, use the -ch alias with its leading hyphen, or type CHANGE in full.
The command has no button on the ribbon, no entry in the classic menus and no place on any toolbar. It can only be typed. Using the Properties palette is covered in our article on the Properties palette.
The prompts, step by step
Autodesk sums the command up in one line: "Changes the properties of existing objects." The middle column below quotes the 2027 prompts exactly.
| Step | The prompt | What you do |
|---|---|---|
| 1 | Select objects: | Select objects, Enter |
| 2 | Specify change point or [Properties]: | Pick a point, or type P |
Step 2 is what sets this command apart. The same picked point does different things depending on whether you selected lines, circles or text, as the first four examples show.
Example 1: change point on a single line
Draw a line from 0,0 to 1000,0. Type -CH, select it, Enter. At the change point prompt, type 1000,500.
The end at 1000,0 moves to 1000,500. The end at 0,0 stays put. The line is now 1,118.03 long, which checks out: the square root of 1000² plus 500².
Which end moves? The CHANGE page from Autodesk answers: "Moves the endpoints of the selected lines that are closest to the change point to the new point". Whichever end is closer to the change point is the one that moves.
Example 2: converge line ends to one point
This is where CHANGE beats every other method. Draw two parallel lines: 0,0 to 800,0, and 0,600 to 800,600. Type -CH, select both, Enter. Type the change point 1200,300.
The right-hand ends of both lines move to exactly 1200,300. The lines now meet at one point, each 1,236.93 long, forming a V on its side. Again the figure checks out: each line now runs 1200 across and 300 up or down, and the square root of 1200² plus 300² is 1,236.93. The left-hand ends, farther from the change point, did not move at all.
The practical uses are many: grid lines that should converge but miss by a few millimetres, rafters that must meet at the ridge, leader lines that should gather at one point. Instead of dragging each end by its grip, select them all and use -CH once.
AutoCAD treats each line separately: for every line, whichever end is closer to the change point is the one moved. So when selecting many lines, place the change point on the side of the ends you want to gather. If a line's other end happens to be closer, the wrong end moves and that line flips round. Before picking, check that the ends you want to gather all lie on the same side.
Example 3: change a circle radius
Draw a circle centred on 0,0, radius 100. Type -CH, select it, Enter, and type the change point 0,300.
The circle keeps its centre and its radius becomes 300, exactly the distance from the centre to the point you gave. With a single circle selected, AutoCAD asks nothing further after the change point; the command simply ends.
Autodesk describes it as "Changes the circle radius. If you selected more than one circle, the prompt is repeated for the next circle." Select several circles and AutoCAD asks for each in turn.
This suits the case where a circle must pass through a known point, such as the corner of a column, and you do not know the radius in advance. Pick that point and you are done. Other ways to draw circles are covered in our article on circles in AutoCAD.
Example 4: ORTHO mode and CHANGE
This one surprises people. Draw a sloping line from 0,0 to 1000,300. Turn on orthogonal mode by typing ORTHOMODE and setting it to 1. Type -CH, select the line, Enter, and type the change point 700,900.
The result is not a line running to 700,900. The line becomes vertical, from 0,0 to 0,900: the same X as the fixed end, the same Y as the point you gave. It is exactly 900 long, against the 1,044.03 of the original sloping line. In this example the vertical result follows the larger of the two offsets: from the fixed end, the picked point is 700 across but 900 up.
Autodesk says so plainly: "If Ortho mode is on, the selected lines are modified so that they become parallel to either the X or the Y axis; their endpoints are not moved to the specified coordinate."
So when you want CHANGE to move a line end to an exact point, make sure ORTHO is off. And when you want to straighten a batch of slightly sloping lines into verticals or horizontals, turning ORTHO on and using this command is very quick.
Example 5: change properties, and change text
Type P at the change point prompt and the command switches to properties. AutoCAD asks, word for word, Enter property to change [Color/Elev/LAyer/LType/ltScale/LWeight/Thickness/TRansparency/Material/Annotative]:
Draw a line on layer 0. Type -CH, select it, Enter, type P, type LA, and enter a new layer name, for example WALL. The line moves to layer WALL. AutoCAD then offers the property list again so you can change something else; press Enter once more to finish.
In that list the capital letters are the shortcut you type.
| Type | Property |
|---|---|
C | Colour |
E | Elevation along Z |
LA | Layer |
LT | Linetype |
S | The object's own linetype scale |
LW | Lineweight |
T | Thickness along Z |
TR | Transparency |
M | Material |
A | Annotative |
You can change several properties in one go; after the layer, type C to change the colour as well.
For single-line text, the command asks in turn for the insertion point, style, height, rotation and content. Write ABC at a height of 100, run -CH, select it and answer as follows.
| The prompt | You type |
|---|---|
Select objects: | Select the text, Enter |
Specify change point or [Properties]: | Enter |
Specify new text insertion point <no change>: | Enter |
Enter new text style <Standard>: | Enter |
Specify new height <100.0000>: | 250 |
Specify new rotation angle <0>: | Enter |
Enter new text <ABC>: | IIC |
The text becomes IIC, 250 high, still at its original insertion point. A second line of text nearby that was not selected keeps its height of 100 and its original wording.
When to use CHANGE, and when to use Properties
| The job | Better tool |
|---|---|
| Bring the ends of many lines to one point | CHANGE |
| Straighten a batch of lines to vertical or horizontal | CHANGE with ORTHO on |
| Make a circle pass through a known point | CHANGE |
| Change layer, colour or linetype for many objects | Properties palette, more visual |
Picking empty space at the selection step makes AutoCAD report 0 found and change nothing, so experimenting with this command carries no risk. If you change something by mistake, a single U puts it back.
Frequently asked questions
What is the alias for the change command in AutoCAD?
-CH, with the hyphen. Typing CH without it opens the Properties palette.
Which end of the line moves?
The end closer to the change point. The other end stays where it is.
Why does the line not reach the point I picked?
ORTHO is on. The command then straightens the line parallel to X or Y instead of moving its end to the point.
How do I change a circle's radius with CHANGE?
Select the circle, press Enter, then pick a point. The new radius is the distance from the centre to that point.
Is CHANGE on the ribbon?
No. It has no ribbon button, menu entry or toolbar button; it can only be typed.
Can CHANGE bring the ends of several lines to one point?
Yes, and this is its most useful job. Select all the lines, press Enter, and pick the meeting point. For every line, the end nearer that point moves onto it, while the far end stays exactly where it was.