TOOL GUIDING & SETTING DEVICES

(JIG BUSHES, TENONS & CUTTER SETTERS)

DRILLING AND REAMING JIG

REAMING ALLOWANCES

• H7 HOLE ( REAMED HOLE) CAN BE OBTAINED IN DRILL JIG BY CHANGING THE SLIP DRILL BUSH WITH REAMING BUSH

• THE REAMING ALLOWANCE IS GENERALLY TAKEN AS 0.1 M.M / SIDE TO 0.15 MM/ SIDE

ERRORS IN DRILL JIGS

• EXTENT OF THE ERROR BETWEEN JIG BUSH AND DRILL ( F7 / h8)

• EXTENT OF THE CENTER DISTANCE TOLERANCE ERROR BETWEEN THE TWO JIG BUSH HOLES ( +/- 0.01 M.M)

• EXTENT OF THE ERROR BETWEEN SLIP DRILL BUSH AND LINER BUSH ( H7 / g6)

• EXTENT OF THE CONCENTRICITY ERROR OF LINER AND JIG BUSHES ( 0.005 )

• FUNCTION OF A TENON IS TO ESTABLISH RELATION BETWEEN FIXTURE AND MILLING MACHINE

• THE ACCURACY OF A WORK PIECE DEPENDS ON THE ACCURACY OF GUIDE WAYS OF A MILLING MACHINE AND THE CLEARANCE BETWEEN GUIDE WAYS AND TENON.

• GUIDE WAYS TOLERANCE – H8• TENON TOLERANCE - j6

ERRORS IN GUIDING SYSTEM

CUTTER SETTER ERRORS IN MILLING:

CUTTER SETTER POSTIONAL ERROR WITH RESPECT

TO DATUM OF FIXTURE IS AROUND 0.02 M.M.

LOCATOR PLATE POSITIONAL ERROR WITH RESPECT

TO DATUM OF THE FIXTURE IS AROUND 0.02 M.M.

CUTTER SETTING

SECTION A-A