To withstand the strictly perpendicular direction when drilling holes in the wall or to any vertical surface— just attach to a drill with tape or duct tape carpenter’s level. His shifty air bubble in a glass tube, show that you have not rejected the tool from the horizontal.
Recommend to read
THE HAMMER-WEDGE
Each of us happened more than once to dismantle many firmly downed wood planks or boards. Great helper in this work, the hammer-wedge. They are on sale. In principle, any hammer can be...
ACOUSTIC PROBE
The magazine "Amaterske Radio" (Czechoslovakia) proposed scheme is a simple audio probe to detect logic levels; low (logic 0) and high (logical 1). The device consists of a bitonal...
