Machining is achieved by knowing the machine parts, feed rates and the proper
speeds based on the rigidity of the workpiece as well as cutting tool. Turning
process works to remove material from the rotating workpiece surface and
reducing its diameter for each spindle revolution or rpm, this operation could
be taper turning, form turning, and contour turning, drilling, knurling,
threading or boring.
Spindle speed is
calculated as rpm= (CS*320)/D where rpm represents revolutions per minute of
the cutter or workpiece, CS=cutting speed, D=diameter
Feed rate is the
multiplication of calculated speed, number of teeth of the cutter and chip
load(feed per tooth).
Feed
per tooth=feed/(spindle speed*number of flutes)
Straight cut depth when cutting threads on the lathe=0.6134*pitch
Straight cut depth when cutting threads on the lathe=0.6134*pitch
Range
of feed per revolution for roughing on a lathe machine:
Work material
|
High speed steel
|
carbide
|
||
Inches
|
millimetres
|
inches
|
millimetres
|
|
Mild
steel
|
0.010-0.020
|
0.25-0.5
|
0.015-0.035
|
0.4-0.9
|
Tool
steel
|
0.010-0.020
|
0.25-0.5
|
0.015-0.035
|
0.25-09
|
Cast
iron
|
0.015-0.025
|
0.4-0.65
|
0.015-0.030
|
0.4-0.75
|
aluminum
|
0.015-0.030
|
0.4-0.75
|
0.015-0.035
|
0.4-0.9
|
brass
|
0.015-0.025
|
0.4-0.65
|
0.015-0.030
|
0.4-0.75
|
Other operations are:
About
boring machining, cutting is performed inside the material either horizontal or
vertical.
Milling machine allows work part to be fed
past a rotating tool with edges.
Further,
hacksaw machine is used for linear reciprocating motion while bandsaw helps with linear
continuous motion.
Finishing
improves the product appearance could be done with filing.
Knurling
helps to form ridges increasing the diameter of the workpiece unto 0.030 inch and
this process should be performed with high feed rate and at low spindle speed.
Grinding
produces required sizes with fine finishing.
Durable and reliable metalworking machines as follows Lathe Machine
|