Even when the blade cut along a wooden ruler — there is no guarantee that the edge, huddling, does not crash or find yourself on it.
This will not happen if the shaver to wear a paperclip as shown: she cut off the blade from the line and the cut goes right.
Recommend to read
ATLAS PROFILES
PROFILE "NACA-6409". Developed in the early 30-ies in the aerodynamic laboratory of the NAC (USA) for lifting aircraft-biplanes. This profile can be recommended as models of gliders...
Automatic bee feeder and waterer
When I leased three apiaries with the right to buy them out, I realized how difficult it is to maintain a large number of bee colonies. I solved some of the problems with a feeder-drinker,...