metal removal Flashcards
milling?
The milling is a metal removal operation by means of a multi-point rotary cutter attached to the machine spindle which advances in the material fixed on the machine bed. In this operation, the cutter takes the cutting motion and the workpiece usually takes the feed motion. Milling is typically used to produce parts that are not axially symmetric and have many features, such as holes, slots, pockets, and even three dimensional surface contours.
metal cutting parameters?
- relative motion between tool and workpiece
- shape of tool
- material of tool and work piece
feed?
relative motion of tool in turning on miiling machines
speed?
rotation of object in RPM.
speed=N*pie*Do
N= spindle speed
depth of cut?
Do -DF /2
+ve rake?
Sharp & pointed tool HSS are given +ve rake angle Low strength materials Not preferred for high speed operations
-ve rake?
Greater tool strength Enhances surface finish Carbide tools are given –ve rake angles Usually for high speed cutting
turning?
- center lathe machine
- work piece in chuck
- tool in tool post
- tail stock to hold work piece
- feed is cross or longitudinal
- single point
facing?
- cross feed
- Removing metal from the end of the workpiece to produce a flat surface perpendicular to the axis of the machine.
- single point
drilling?
- tool is fixed to tail stock
- longitudinal feed
- multipoint
- Making a hole
counter sinking?
- longitudinal feed
- single point
- to make an entrance for the drill bit
tapering?
- To make a conical shape
- single point
- longitudinal
- tanx=D1 - D2 /2L
boring?
- longitudinal
- single point
- to increase a hole’s diameter
inner threading?
- To make an inner threading for a nut to be assembled with a screw.
- longitudinal
- single point
chamfering?
- To convert sharp edges to an angular shapes
- vertical milling machine
- longitudinal
- multipoint
undercut?
- cross
- To decrease the diameter of a certain part at the middle of the WP.
- single point
cutoff?
- cross
- To cut the product from a shaft.
- single point
knurling?
- cross
- To make criss-cross shapes.
- random point
up/conventional milling?
- tool cuts to the right
- feed is to the left
- high force
- bad surface finish and tool life
- gears and slots at low cost
climb milling?
- cutting and feed have same direction
- cutting is counterclockwise
- for large objects
counter boring?
- Impression to accommodate the head of the screw.
- single point
*
counter sinking?
- To make an entrance for the drill bit
- single point
reaming?
- Finishing holes with standard diameters
- multipoint
tapping?
- In case of inner threading inside a hole.
- multipoint
broaching?
- linear motion
- for complex cuts
grinding?
- removing thin layer
- tool: grinding wheel
- used for its accuracy, great surface finish and machining complex cutoffs
abrasive type?
- coarce=big
- fine = small
grain size?
- small amount of particles = rough object
- big amount of particles = fine obj.
grade?
- abc= soft
- xyz= hard
