In AutoCAD drawings, the objects' shapes are drawn with fills, as if they were fonts.

I can make the fills "transparent" and the strockes "1 pt," although this is just a cosmetic solution.

In many instances, however, it is impossible to enlarge the modified objects, as they develop "spikes" at the ends of each segment.

As a workaround, I redraw in a new layer the shape of the object using regular lines (strokes, no fills), but this is incredibly time consuming.

Is there a better way to convert the shapes into regular lines?

Thanks!