1. Mechanical engineering

2.  Prepared By: 1. Solanki Mohit (130310119051) 2. Solanki Vishal (130310119052) 3. Sonagra Gopal (130310119053) 4.Thoriya Savjit (130310119054) 5. Vachhani Denish (130310119055)  Guided By S. I. Patel

3.  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.

4.  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.

5.  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.

6. Sketch of drilling

7.  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.

8.  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

9.  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.

10.  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.

11. MaterialCoolantPoint angle In Deg. Leap clearance Chisel point Helix angle Aluminium2/3lard oil 90-14012-17125-13524-48 Brass2/3lard oil 11812-15125-1350-17 Cast ironSoluble oil11810-12125-13524-32 CopperSoluble oil100-11812-15125-13528-40 Nickel pureLard oil11812125-13524-32 Stainless steel Sulphur base oil 125-13510-12120-13024-32 SteelSoluble oil11812-15125-13524-32

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