Mechanical engineering

 Prepared By: 1. Solanki Mohit ( ) 2. Solanki Vishal ( ) 3. Sonagra Gopal ( ) 4.Thoriya Savjit ( ) 5. Vachhani Denish ( )  Guided By S. I. Patel

 For this purpose we have to design a machine by which material can drilled quickly and at a low cost.  The hole is generated by the rotating edge of a cutting tool which known as the drill which exerts large force on the work clamped on the table.  For our purpose we can use small drill machine. It’s also known as portable drilling machine.

 This type of drilling machine can be operated with ease any where in the workshop  It is used for drilling holes in work pieces in any position which can not be drilled in a standard drilling machine.  Mostly in drilling machine small and compact motor is used.

 The motor is usually of universal type which may be driven by both A.C. and D.C.  Maximum size of drill that it can accommodate is more that 12-18mm.  The machine is operated at high speed as smaller size drills are only used.  Some of the portable drill machines are driven by pneumatic power.

Sketch of drilling

 In the Drill has base which is that part of the machine on which vertical column is mounted.  The column is vertical member of machine which support the table and the head containing hold the driving mechanism.  Table is mounted on the column and is provided with T-slots for clamping the work directly on its face.  Head is mounted on the column and houses the driving and feeding mechanism for the spindle.  Spindle is a vertical shaft which holds the drill.

 The types of the drill commonly used are: 1) Flat or spade drill 2) Straight fluted drill 3) Two-lip twist drill 4) Taper shank core drill 5) Oil tube drill 6) Centre drill

 For our purpose straight fluted drill gives best result in soft material.  A straight fluted drill has grooves or flutes running parallel to the drill axis.  This type of drill is inconvenient in standard practice as the chips do not come out from the hole automatically.  It is mainly used drilling brass, copper or other softer material.

 In drilling brass, the twist drill tends to advance faster than the rate of feed and the drill digs into the metal.  No such difficulty occurs in the use of a straight fluted drill when drilling sheet metal.  The straight fluted drill does not tend to lift the sheet as does the twist drill.

MaterialCoolantPoint angle In Deg. Leap clearance Chisel point Helix angle Aluminium2/3lard oil Brass2/3lard oil Cast ironSoluble oil CopperSoluble oil Nickel pureLard oil Stainless steel Sulphur base oil SteelSoluble oil

 Workshop technology vol.:2 published by media promoters. Authors are S.K.hajra chaudhary A.K.hajra chaudhary Nirjhar roy