Plotter blades geometry

GIS Premium Blades

Angles, offset, overcut

Wedge angle? 

Clearance angle?

Cutting edge angle?

Offset?

Orthogonal to cutting direction

Plotter blade wedge angle
Cutting direction

Plotter blade clearance angle
Cutting direction

Plotter blade cutting edge angle
Cutting direction

Plotter blade offset
The angle across the cutting edge measured at the point of the tip. The angle between the foil surface and the cutting edge.
The angle between the front and rear edge of the blade. The distance by which the blade's tip follows the symmetry line (for drag blades only).
Usually applies: α + β = 90°. With double-sided blades, the cutting edge angle is measured from edge to edge.

 

Overcut

Plotter blade overcut Plotter blades overcut
The overcut is the measure between the symmetry line of the blade and the intersection point of the cutting edge with the material surface. The overcut slightly alters contours on curves, but in practice this is usually insignificant.

The deformation can be reduced by selecting blades with a steep clearance angle α . It is not possible to cut completely without any overcut, the blade would then have to be "infinitely steep".
A single-sided plotter blade creates an overcut only to the front. A double-sided plotter blade creates an overcut to the front and back.

This is usually helpful for weeding, but can be unfavorable for filigree motifs or for repro work with masking film ("sparks").