Always sand in perpendicular direction to skin
Always sand in perpendicular direction to skin

When using zigzag, at least.

Contributes to issue CURA-3903.

ROBO3D/CuraEngine,ROBO3D/CuraEngine,ROBO3D/CuraEngine,alephobjects/CuraEngine,alephobjects/CuraEngine,Ultimaker/CuraEngine,Ultimaker/CuraEngine,alephobjects/CuraEngine