Dimensional Constraints (DCLINEAR, DCRADIUS ...)

Add constraints that hold a value (distance, radius, diameter, angle) and convert dimensions into constraints.

What it does

A dimensional constraint forces a size to a value you set. When you change the value, the shape changes with it.

Where to find it

Ribbon: Parametric › Dimensional (Linear, Radius, Diameter, Angular) and Auto Constrain ▾ › Convert dimensions (DCCONVERT)

Commands

Command	Alias	Meaning
DCLINEAR	`DCL`	The distance between the start points of two lines. Select exactly 2 lines; it does not set the length of a single line.
DCRADIUS	`DCR`	The radius of a circle.
DCDIAMETER	`DCD`	The diameter of a circle.
DCANGULAR	`DCA`	The angle between two lines.
DIMCONSTRAINT	`DIMCON`	`DIMCONSTRAINT <distance\|radius\|diameter\|angle> [value]`
DCCONVERT	–	Converts dimensions that are attached to objects into constraints. Free dimensions placed by clicking points cannot be converted.

Steps

Select the objects.
Type DCRADIUS 25 and press Enter (give the value after the command), or click the button on the Ribbon and enter the value in the dialog that opens.
The solver adjusts the shape and reports the remaining DOF.

Try it: Desk cable grommet ring

An acrylic ring that dresses up the cable hole in a desk: 60 mm outside, with an inner hole sized to your cables. Sketch two circles at any size, then let the constraints set the exact numbers, and change them later.

Draw two circles that are deliberately a bit off: C, 0,0, 27, Esc. Then C, 4,3, 17, Esc.
Click the outer circle and type DCDIAMETER 60. The result reads DIAMETER: 1 constraint(s) satisfied; 5 DOF remaining.
Click the inner circle and type DCDIAMETER 40.
Click the outer circle, Ctrl+click the inner circle, and type GCCONCENTRIC. Both circles now share one centre.
The power plug needs a bigger hole: type CBAR to see the list (#0 diameter(#0) = 60; #1 diameter(#1) = 40; #2 concentric(#0, #1)), then DELCONSTRAINT 1. Click the inner circle and type DCDIAMETER 44. The ring updates and stays centred.

Grommet ring with Ø60 outer and Ø44 inner circles

Challenge: Make the ring 70 mm outside the same way: CBAR to find the number, DELCONSTRAINT it, then DCDIAMETER 70 on the outer circle.