CHAPTER 23 - Machining Processes used to Produce Various Shapes

EXAMPLE 23.1 - PG NO 600

In [1]:
#Example 23.1
#page no. 600
# Given that
import math
l=12.#in inch Length of block
w=4
f=0.01#in inch/tooth feed  
d=0.125#in inch depth of cut
D=2.#in inch diameter of cutter
n=20.#no. of teeth
N=100.#in rpm spindle rotation
Vt=8.#in inch/minute axial speed of the tool

# Sample Problem on page no. 600

print("\n # Material Removal Rate , Power required and Cutting Time in slab milling # \n")

v=f*N*n
MRR=w*d*v 
print'%s %d %s' %("\n\n Material Removal Rate = ",MRR," in^3/min")

#for annealed mild steel unit power is taken as 1.1 hp min/in3
P=1.1*MRR
print'%s %d %s' %("\n\n Cutting power=",P,"hp")

T=P*33000/(N*2*3.14)
print'%s %d %s' %("\n\n Cutting torque=",T,"lb-ft")

lc=math.sqrt(d*D)
t=(300.+12.2)/500.
print'%s %.6f %s' %("\n\n Cutting time=",t*60,"sec")

#Answers vary due to aproximations 
 # Material Removal Rate , Power required and Cutting Time in slab milling # 



 Material Removal Rate =  10  in^3/min


 Cutting power= 11 hp


 Cutting torque= 578 lb-ft


 Cutting time= 37.464000 sec

EXAMPLE 23.2 - PG NO 655

In [2]:
#example 23.2
#page no. 655
# Given that
l=500#in mm Length
w=60#in mm width
v=0.6#in m/min  
d=3#in mm depth of cut
D=150#in mm diameter of cutter
n=10#no. of inserts
N=100#in rpm spindle rotation

# Sample Problem on page no. 655

print("\n # Material Removal Rate , Power Required and Cutting Time in Face Milling # \n")

MRR=w*d*v*1000. 
print'%s %d %s' %("\n\n Material Removal Rate = ",MRR,"mm^3/min")

lc=D/2.
t=((l+(2.*lc))/((v*1000.)/60.)) # velocity is converted into mm/sec
t1=t/60.
print'%s %.6f %s' %("\n\n Cutting time= ",t1,"f min")

f=(v*1000.*60.)/(60.*N*n) # N is converted into rev/sec by dividing by 60 , velocity is converted into mm/sec
print'%s %.6f %s' %("\n\n Feed per Tooth =",f,"mm/tooth")

#for high strength aluminium alloy unit power is taken as 1.1 W s/mm3
P=(1.1*MRR)/60. # MRR is converted into mm3/sec by dividing by 60
P1=P/(1000.)#in KW
print'%s %.6f %s' %("\n\n Cutting power =",P1,"KW")
 # Material Removal Rate , Power Required and Cutting Time in Face Milling # 



 Material Removal Rate =  108000 mm^3/min


 Cutting time=  1.083333 f min


 Feed per Tooth = 0.600000 mm/tooth


 Cutting power = 1.980000 KW