As one of the most commonly used commands in AutoCAD, Fillet is essential and we cannot imagine working without using it! However, sometimes no matter how hard we are trying Fillet just won’t connect those two polylines (or line and polyline).
Now we are going to look at most common problems that interfere with command’s behavior.
Lines (Polylines) lay in different planes
This is may be the most common problem. If one of the vertexes of our line has Z coordinate, or our 2D polyline has an Elevation, AutoCAD won’t be able to connect them. This happens because AutoCAD is 3D capable software and cannot connect objects that have no intersection point in 3D space. To make it work you just have to change all Elevations to 0, or at least have them at equal one.
TRIMMODE system variable
Other times the issue may be one system variable – TRIMMODE. If it is set to 0 selected objects – Lines or Polylines cannot be trimmed before the Fillet is added and you end up with not working command.
You can correct that by simply typing TRIMMODE on the command line and set the value to 1
Direction of the polyline
This is very strange, but in some rare cases, polylines will not fill if they have different directions. Sometimes they do connect but as said earlier in some really rare cases reversing the direction of the polyline can help you use Fillet.
Changing the direction of a polyline can be done by typing PE on the command line, then you have to select the polyline you want to reverse and AutoCAD will ask you to choose from several options. You just choose reverse and you are done!
Coordinates of line’s vertexes
In other rare cases it the problem might be in the coordinates of Line or Polyline vertex. In that case, you can just move the vertex somewhere along the line and try again.
Have you ever had a problem joining polylines? If yes take a look at our post about joining Polylines – a method that works every time!