FILLET

FILLET joins two objects with a rounded corner. It draws an arc of the radius you choose and trims or extends both objects so they meet it exactly. With a radius of 0 it makes a clean, sharp corner.

How it works

Type F and press Enter. Musa CAD shows the current mode and radius. Set the radius with Radius if you need a new one. Then pick the first object and the second. Pick each one on the part you want to keep. The corner is rounded and the command ends.

Command line

Command: F
Current settings: Mode = TRIM, Radius = 0.0000
Select first object or [Undo/Polyline/Radius/Trim/Multiple]: R
Specify fillet radius <0.0000>: 12
Select first object or [Undo/Polyline/Radius/Trim/Multiple]: (pick the first line)
Select second object or shift-select to apply corner or [Radius]: (pick the second line)
Filleted.

Pick 1, then 2, with the radius set to 12.

Plotted by Musa CAD 0.8.0 from the example drawing cmd-fillet.musaDownload the drawing

While you move over the second object, Musa CAD shows the result a click would make: both objects as they would be, and the arc.

Hold Shift as you pick the second object to make a sharp corner this once, whatever the radius.

Options

Option	What it does
Undo (U)	Takes back the last fillet made in this run. Useful with Multiple.
Polyline (P)	Rounds every corner of a 2D polyline at once. Asks Select 2D polyline or [Radius]:, then reports how many corners it rounded, such as 4 lines were filleted.
Radius (R)	Asks Specify fillet radius <0.0000>:. Type the new radius, or press Enter to keep it. Also offered at the second prompt.
Trim (T)	Asks Enter Trim mode option [Trim/No trim] <Trim>:. Trim cuts or extends the objects to meet the arc. No trim leaves them as they are and only adds the arc.
Multiple (M)	Keeps asking for pairs, so you can round many corners. Press Enter to stop. Each corner is its own undo step.
Enter at Select first object	Ends the command.

What FILLET can join

• Two lines. Both are trimmed or extended to meet the arc. At radius 0 they meet in a sharp corner.
• Two parallel lines. They are joined by a half circle as wide as the gap, at the end of the first line nearer where you picked it. The second line is trimmed or extended to meet it. The radius is not used.
• An arc or circle with a line, arc or circle, and an ellipse or spline with any of these. The arc touches both smoothly, and each object is cut back to it on the side you picked. A circle or a whole ellipse stays whole. These need a radius greater than 0.
• A line and an open polyline, or two open polylines. Pick the polyline’s straight end segment. The two become one polyline with the corner rounded.
• Two segments of one polyline that meet. That corner is rounded, and the arc becomes part of the polyline.
• Construction lines and rays. They are treated as the line they run along. What stays of a construction line is a ray.

Settings FILLET remembers

The radius and the Trim mode are kept for the next time, for as long as Musa CAD stays open. The first line of each run shows them.

• The radius is the FILLETRAD setting. Type FILLETRAD to set it directly.
• The Trim mode is the TRIMMODE setting: 1 for Trim, 0 for No trim. CHAMFER uses the same setting, so changing it in one changes it in the other.

Good to know

• A radius too big for the lines is refused with Fillet: radius too large for these lines.
• An arc, circle, ellipse or spline at radius 0, including a Shift pick, is refused with Fillet: a radius greater than 0 is needed to fillet a curve.
• Fillet: no arc of that radius is tangent to both objects. means no arc of that size can touch both. Try another radius.
• Radius 0 with No trim has nothing to add: Fillet: nothing to add with radius 0 in No trim mode.
• With Polyline, corners too short for the radius are skipped and counted at the end of the message. If none fit, Musa CAD says Fillet: the radius fits none of the polyline's corners.
• The trimmed objects keep their layer, colour and linetype. The new arc takes the objects’ properties when both are on the same layer, and otherwise goes on the current layer. A fillet between an arc or circle and a line, arc or circle always puts the new arc on the current layer.
• At the Trim mode prompt, Enter chooses Trim, even when the default shown is No trim. Type N to keep No trim.
• Undo takes back only the most recent fillet. After that it says Nothing to undo.

Compared with AutoCAD

FILLET uses AutoCAD’s prompts and options. As in AutoCAD, two parallel lines are joined by a half circle, the new arc takes the objects’ properties when they share a layer, and the Trim mode is shared with CHAMFER.

Next

• Cut a straight bevel across a corner instead with CHAMFER.
• Draw a rectangle with rounded corners in one go with RECTANG.
• See all the editing commands together in Modifying objects.