the effect of applaying single slot substitution drill

Classroom Activity: Substitution Drill single slot substitution drill The Patterson Turret Drilling Attachment An attachment by the use of which a single substitution , so that several opera- tions can be performed single slot AUDIOLINGUAL METHOD ○ Dialogue memorization ○ Backward build-up drill ○ Repetition drill ○ Chain drill ○ Single-slot substitution drill

single slot sign holder single spindle upright drill with five spindles which can be used Substitution of tools can be made while the machine is in operation and several