Solutions for Fundamentals of Modern Manufacturing , 5/e (published by Wiley) MPGroover 2012
OPERATIONS AND MACHINE 21 MACHINING OPERATIONS TOOLS Review Questions 21.1 21.1
Wht Wht re the the differe differen!es n!es bet" bet"een een rott rottion ionl l prts prts nd nd pris#t pris#ti! i! prts prts in #!h #!hini inin$% n$% Answer. &ottionl prts re !ylindri!l or dis'shped nd re #!hined on turnin$ #!hine (e.$., lthe) pris#ti! prts re blo!'shped or flt nd re $enerlly produ!ed on #illin$ #!hine, shper, or plner.
21.2 21.2
*istin *istin$ui $uish sh bet"ee bet"een n $enerti $enertin$ n$ nd for# for#in$ in$ "hen "hen #!hini #!hinin$ n$ "or' "or' prt prt $eo#etr $eo#etries ies.. Answer. Genertin$ refers to the !retion of "or' $eo#etry due to the feed tr+e!tory of the !uttin$ tool e#ples in!lude stri$ht turnin$, tper turnin$, turnin$, nd profile #illin$. -or#in$ involves the !retion of "or' $eo#etry due to the shpe of the !uttin$ tool !o##on e#ples in!lude for# turnin$ nd drillin$.
21. 21.
Give Give t"o e#p e#ples les of #!hi #!hinin nin$ $ operti opertions ons in "hi!h "hi!h $ener $enerti tin$ n$ nd for#i for#in$ n$ re !o#bi !o#bined ned to !rete "or' prt $eo#etry. Answer. he t"o e#ples $iven in the tet re thred !uttin$ on lthe nd slot #illin$.
21. 21.
*es! *es!ri ribe be the the tur turni nin$ n$ pro! pro!es ess. s. Answer. urnin$ is #!hinin$ pro!ess in "hi!h sin$lepoint tool re#oves #teril fro# the surf!e of rottin$ !ylindri!l "or'pie!e, the tool bein$ fed in dire!tion prllel to the is of "or' rottion.
21.5 21.5
Wht Wht is the the dif diffe feren ren!e !e bet" bet"ee een n thre thred din in$ $ nd nd tppi tppin$ n$%% Answer. thredin$ opertion is perfor#ed on turnin$ #!hine nd produ!es n eternl thred, "hile tppin$ is nor#lly perfor#ed on drillin$ #!hine nd produ!es n internl thred.
21. 21.
3o" does does borin$ borin$ opert opertion ion differ differ fro# fro# turnin turnin$ $ oper operti tion% on% Answer. 4orin$ produ!es n internl !ylindri!l shpe fro# n eistin$ hole, "hile turnin$ produ!es produ!es n etern eternll !ylindri!l !ylindri!l shpe. shpe.
21. 21.
Wht Wht is is #en #entt by the the desi desi$n $nt tio ion n 12 in!h in!h lth lthe% e% Answer. 12 lthe hs 12 in!h s"in$ (#i#u# "or' di#eter tht !n be !!o##odted) nd in!h distn!e bet"een !enters (indi!tin$ the #i#u# "or' len$th tht !n be held bet"een !enters). !enters).
21.6 21.6
7#e the vriou vriouss "ys "ys in in "hi! "hi!h h "or' "or' prt prt !n !n be held held in lthe lthe.. Answer. Methods of holdin$ the "or' in lthe in!lude8 (1) bet"een !enters, (2) !hu!', () !ollet, nd () f!e plte.
21.9 21.9
Wht Wht is the the differe differen!e n!e bet"e bet"een en live live !enter !enter nd nd ded !ent !enter er,, "hen thes thesee ter#s ter#s re used used in the the !ontet of "or'holdin$ in lthe% Answer. !enter holds the "or'pie!e t the tilsto!' end of the lthe. live !enter is #ounted in berin$s berin$s nd rottes rottes "ith the "or', "or', "hile "hile ded ded !enter !enter does not rotte rotte the the "or' rottes bout it.
21.10 21.10
3o" does does turr turret et lthe lthe dif differ fer fro# fro# n en$i en$ine ne lthe lthe%%
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Solutions for Fundamentals of Modern Manufacturing , 5/e (published by Wiley) MPGroover 2012
Answer. turret lthe hs toolholdin$ turret in pl!e of tilsto!' the tools in the turret !n be brou$ht brou$ht to "or' "or' to perfor# perfor# #ultiple #ultiple !uttin$ !uttin$ opertions opertions on on the "or' "ithou "ithoutt the need need to !hn$e tools s in opertin$ !onventionl en$ine lthe.
21.1 21.11 1
Wht Wht is bli blind nd hole hole%% Answer. blind hole does not eit the "or' by !o#prison, throu$h hole eits the opposite side of the "or' prt.
21.12 21.12
Wht Wht is the disti distin$u n$uish ishin$ in$ fetu feture re of rdil rdil drill drill press% press% Answer. rdil drill hs lon$ rdil r# lon$ "hi!h the drill hed !n be positioned to llo" the drillin$ of lr$e "or' prts. he rdil r# !n lso be s"iveled bout the !olu#n to drill prts on either side of the "or'tble.
21.1
Wht is the the differen differen!e !e bet"een bet"een peripherl peripherl #illin$ #illin$ nd nd f!e f!e #illin$% #illin$% Answer. ;n peripherl #illin$, !uttin$ is !!o#plished by the peripherl teeth of the #illin$ !utter nd the tool is is prllel to the "or' surf!e in f!e #illin$, !uttin$ is !!o#plished by the flt f!e of the !utter "hose is is perpendi!ulr to the "or' surf!e.
21.1 21.1
*es! *es!ri ribe be prof profil ilee #il #illi lin$ n$.. Answer. Profile #illin$ $enerlly involves the #illin$ of the outside periphery of flt prt.
21.1 21.15 5
Wht Wht is is po!' po!'et et #il #illi lin$ n$%% Answer. Po!'et #illin$ uses n end #illin$ !utter to #!hine shllo" !vity (po!'et) into flt "or' prt.
21.1
*es!ribe *es!ribe the the differen!e differen!e bet"een up #illin$ #illin$ nd do"n #illin$. #illin$. Answer. ;n up #illin$, the !utter speed dire!tion is opposite the feed dire!tion in do"n #illin$, the dire!tion of !utter rottion is the s#e s the feed dire!tion.
21.1
3o" does does univers universll #illin$ #illin$ #!hine #!hine differ differ fro# fro# !onventi !onventionl onl 'neend!o 'neend!olu#n lu#n #!hine% #!hine% Answer. he universl #illin$ #!hine hs "or'tble tht !n be rotted bout verti!l is to present present the prt prt t ny spe!ified spe!ified n$le to to the !utter !utter spindle spindle..
21.16 21.16
Wht Wht is #! #!hi hini nin$ n$ !enter !enter%% Answer. #!hinin$ !enter is <7< #!hine tool !pble of perfor#in$ #ultiple types of !uttin$ opertions involvin$ rottin$ spindles (e.$., #illin$, drillin$) the #!hine is typi!lly e=uipped "ith uto#ti! tool!hn$in$, pllet shuttles to speed "or' prt !hn$in$, nd uto#ti! "or' prt positionin positionin$. $.
21.19
Wht is the the differen!e differen!e bet"een bet"een #!hini #!hinin$ n$ !enter !enter nd turnin$ turnin$ !enter% !enter% Answer. #!hinin$ !enter is $enerlly !onfined to rottin$ spindle opertions (e.$., #illin$, drillin$) "hile turnin$ !enter perfor#s turnin$ type opertions, $enerlly "ith sin$lepoint tools.
21.20
Wht !n #illturn #illturn !enter !enter do tht !onventio !onventionl nl turnin$ turnin$ !enter !enter !nnot !nnot do% Answer. he #illturn !enter hs the !p!ity to position rottionl "or' prt t spe!ified n$ulr lo!tion, per#ittin$ #illin$ or drillin$ to be perfor#ed t lo!tion on the periphery of the prt.
21.21 21.21
3o" 3o" do shp shpin in$ $ nd pl plni nin$ n$ dif diffe fer% r%
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Solutions for Fundamentals of Modern Manufacturing , 5/e (published by Wiley) MPGroover 2012
Answer. ;n shpin$, the "or' is sttionry durin$ the !ut, nd the speed #otion is perfor#ed by the !uttin$ tool "heres in plnin$, the !uttin$ tool is sttionry, nd the "or' prt is #oved pst the tool in the speed #otion.
21.22
Wht is the the differen!e differen!e bet"een bet"een internl internl bro!hin$ bro!hin$ nd nd eternl eternl bro!hin$% bro!hin$% Answer. ;nternl bro!hin$ is !!o#plished on the inside surf!e (hole) of "or' prt "hile eternl bro!hin$ is perfor#ed on one of the outside surf!es of the prt.
21.2 21.2
;dentify ;dentify the thre threee bsi! bsi! for#s for#s of of s"in$ s"in$ oper operti tion% on% Answer. he three for#s of s"in$ re8 (1) h!'s"in$, (2) bnds"in$, nd () !ir!ulr s"in$.
Probles ns"ers to proble#s lbeled !A" re listed in n ppendi ppendi t the b!' of the boo'. Turnin# $n% Rel$te% O&er$tions
21.1
!A" (S; units) n en$ine lthe is used to turn !ylindri!l "or' prt 150 ## in di#eter by 500 ## lon$. 2.50 #/s, feed > 0.0 ##/rev, nd depth of !ut > .0 ##. *eter#ine () !uttin$ ti#e nd (b) #etl re#ovl rte. Solution8 () " () " > > #/(? $) $) > (2.50 #/s)/0.150 > 5.05 rev/s f r r > "f > "f > > 5.05(.0) > 1.59 ##/s % m > & > &// f f r r > > 500/1.59 > 1 s > '(2) in
lterntive !l!ultion usin$ :=. (21.5), % m > 150(500)?/(2,500 0.0) > 1 s > 5.2 #in (b) ' (b) ' (' > #fd > > (2.50 #/s)(10 )(0.0 ##)(.00 ##) > 22'* +,s 21.2
(S; units) units) ;n produ! produ!tion tion turnin$ turnin$ opertion opertion,, the !ylindri!l !ylindri!l "or'pie!e "or'pie!e is is 5 ## lon$ lon$ nd 150 ## ## in di#eter. -eed > 0.0 ##/rev, nd depth of !ut > .0 ##. Wht !uttin$ speed #ust be used to !hieve #!hinin$ ti#e of 5.0 #in% &/#f . Solution8 Strtin$ "ith :=. (21.5)8 % m > $o &/ &errn$in$ to deter#ine !uttin$ speed8 # > $o &/ &/ f% f% m # > (5)(150)/(0.0)(5.0) > 11,610 ##/#in > 11-(. ,in
21.
(@S in nd len$th > 15 in. he en$ine lthe spindle rottes t 200 rev/#in. *epth of !ut > 0.110 in, nd feed > 0.006 in/rev. ssu#in$ the !uttin$ tool #oves fro# the outer di#eter of the "or'pie!e to e!tly the !enter t !onstnt velo!ity, deter#ine () the velo!ity of the tool s it #oves fro# the outer di#eter to"rd the !enter nd (b) the !uttin$ ti#e. Solution/ () f () f r r > f" > f" > > (0.006 in/rev)(200 rev/#in) > 1(0* in,in (b) & (b) & > > distn!e fro# outside to !enter of prt > 0.5 $ 0.5 $ % m > & > &// f f r r > > 0.5 $/ $/ f f r r > > /(1.) > 1(.-' in
21.
(S; units) units) tpered tpered surf!e surf!e is turned turned on n uto#ti uto#ti!! lthe. lthe. he he "or'pie! "or'pie!ee is 550 ## ## lon$ "ith #ini#u# nd #i#u# di#eters of 100 ## nd 200 ## t opposite ends. uto#ti! !ontrols on the lthe per#it the surf!e speed to be #intined t !onstnt vlue of 200 #/#in by d+ustin$ the rottionl speed s fun!tion of "or'pie!e di#eter. -eed > 0.25 ##/rev, nd depth of !ut > .0 ##. he rou$h $eo#etry of the pie!e hs lredy been for#ed, nd this opertion "ill be the finl !ut. *eter#ine () the ti#e re=uired to turn the tper nd (b) the rottionl speeds t the be$innin$ be$innin$ nd end of the !ut !ut (ssu#e (ssu#e !uttin$ !uttin$ strts strts t t the s#ller s#ller di#eter di#eter). ). Solution8 () ' () ' (' > #fd > > (200 #/#in)(10 ##/#)(0.25 ##)(.0 ##) > 150,000 ## /#in re of frustru# of !one A !one A > > ( ' '1 A ' A '2)Bh )Bh2 A ( ' '1 C ' C '2)2D0.5 Given ' Given '1 > 100 ##, ' ##, '2 > 50 ##, nd h > 550 ##,
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Solutions for Fundamentals of Modern Manufacturing , 5/e (published by Wiley) MPGroover 2012
A > A > (100 A 50)B550 2 A (100 C 50) 2D0.5 > 150(05,000) 0.5 > 20,250 ## 2 Given depth of !ut d > > .0 ##, volu#e !ut ) > Ad > Ad > > (20,250 ## 2)(.0 ##) > 60,51 ## % m > ) / ' ' (' > (60,51 ## )/(150,000 ## /#in) > '(21 in (b) t be$innin$ of !ut ( $ ( $1 > 100 ##), " ##), " > > #/ $ > $ > 200,000/100 > 0+0(0 rev,in t end of !ut ( $2 > 200 ##), " ##), " > > 200,000/200 > +1.(+ rev,in 21.5
(S; units) units) ;n the tper turnin$ turnin$ +ob of Proble# Proble# 21., 21., suppos supposee tht tht the uto#ti! uto#ti! lthe lthe "ith "ith surf!e surf!e speed !ontrol is not vilble nd !onventionl lthe #ust be used. *eter#ine the rottionl speed tht "ould !o#plete the +ob in e!tly the s#e ti#e s in prt () of tht proble#. Solution8 t !onstnt rottionl speed nd feed, feed rte f r r is is !onstnt nd :=s. (21.) nd (21.) !n be used. & > &// "f "f nd nd then rerrn$in$ to obtin rottionl speed " > & > &// f% f% m Given & Given & > > 550 ##, f ##, f > > 0.25 ##/rev, nd % m > 5.21 #in fro# Proble# 21., " > > 550/(0.25)(5.21) > )22(+ rev,in
21.
!A" (@S .5 in nd len$th > 52 in is !hu!'ed in n en$ine lthe nd supported t the opposite end usin$ live !enter. .0 in portion of the len$th is to be turned to di#eter of .25 in one pss t speed of 50 ft/#in. he #etl re#ovl rte should be .5 in /#in. *eter#ine () the re=uired depth of !ut, (b) the re=uired feed, nd (!) the !uttin$ ti#e.
> (.50 .25)/2 > *(12' in Solution8 () depth d > (b) ' (b) ' (' > #fd f > ' > ' ('/(12#d /(12#d ) > .5/(12 50 0.125) > 0.010 in f > > *(*1* in,rev (!) " (!) " > > #/? $ > $ > 50 12/.5 > 62 rev/#in f r r > > 62(0.010) > .62 in/#in % m > /.62 > 12(*) in 21.
(@S 00 ft/#in, feed > 0.015 in/rev, nd depth of !ut > 0.125 in. he br "ill be held in !hu!' nd supported on the opposite end in live !enter. With this "or'holdin$ setup, one end #ust be turned to di#eter then the br #ust be reversed to turn the other end. @sin$ n overhed !rne vilble t the lthe, the ti#e re=uired to lod nd unlod the br is 5.0 #inutes, nd the ti#e to reverse the br is .0 #inutes. -or e!h turnin$ !ut n llo"n!e #ust be dded to the !ut len$th for ppro!h nd overtrvel. he totl llo"n!e (ppro!h plus overtrvel) > 0.50 in. *eter#ine the totl !y!le ti#e to !o#plete this turnin$ opertion. Solution8 -irst end8 !ut 15 in of 0 in len$th. > 00 12/ > 26. rev/#in, f rev/#in, f r r > > 26.(0.015) > .29 in/#in " > % m > (15 A 0.5)/.29 > .1 #in this redu!es di#eter to .5 in " > > 00 12/.5 > 05.5 rev/#in, f r r > > 05.5(0.015) > .56 in/#in % m > 15.5/.56 > .6 #in to redu!e the di#eter to .50 in
&everse the br, "hi!h t'es .0 #in nd !ut the re#inin$ 15 in of 0 in len$th. he #!hinin$ ti#es "ill be the s#e s before be!use the len$th nd di#eters re the s#e. Eodin$ nd unlodin$ br t'es 5.0 #in. otl !y!le ti#e > 5.0 A .1 A .6 A .0 A .1 A .6 > 21(. in 21.6 21.6
(@S 6.0 in, inside di#eter > 20.0 in, nd hei$ht > 16.0 in. ;f the f!in$ opertion is perfor#ed perfor#ed t rottionl rottionl speed speed > 0 rev/#in, rev/#in, feed feed > 0.015 0.015 in/rev in/rev,, nd depth depth of of !ut > 0.160 in,
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Solutions for Fundamentals of Modern Manufacturing , 5/e (published by Wiley) MPGroover 2012
deter#ine () !uttin$ ti#e to !o#plete the f!in$ opertion nd (b) !uttin$ speeds nd #etl re#ovl rtes t the be$innin$ nd end of the !ut. trveled & > > ( $ $o $ $i)/2 > (6 20)/2 > 9.0 in Solution8 () *istn!e trveled & f r r > > (0 rev/#in)(0.015 in/rev) > 0.5 in/#in % m > 9.0/0.5 > 2*(* in (b) t $ t $o > 6 in, " in, " > > #/? $, $, # > " > " ? $ > $ > (0 rev/#in)( 6/12) > 2.(' t,in ' (' > #fd > > (296.5 12)(0.015)(0.16) > (0- in+,in t $ t $i > 20 in, # > " > " ? $ > $ > (0 rev/#in)( 20/12) > 201(. t,in ' (' > #fd > > (21.6 12)(0.015)(0.16) > .(). in+,in 21.9 21.9
(@S 0 rev/#in nd is !ontinuously in!resed therefter to #intin !onstnt !uttin$ speed. (!) Wht is the rottionl speed t the end of the !ut% (b) ' (' is !onstnt throu$hout !uttin$ if # is !onstnt. Solution8 (b) ' # > " > " ? $ > $ > (0 rev/#in)( 6/12) > 2.(' t,in ' (' > #fd > > (296.5 12)(0.015)(0.16) > (0- in+,in () otl #etl re#oved ) (' > 0.25d ( $ $o2 $ $i2) > 0.25(0.160)(6.0 2 C 20.02) > 1. in % m > ) ('/ ' ' (' > 1./9. > 1'(20 in (!) " (!) " > > #/? $ > 296.5 12/?(20) > '- rev,in
Drillin#
21.10
!A" (S; units) drillin$ opertion is perfor#ed on steel prt usin$ 12. 12.##di#eter ##di#eter t"ist drill "ith point n$le > 116 . he hole is blind hole "ith depth of 0 ##. 15 #/#in, nd feed > 0.20 ##/rev. *eter#ine () !uttin$ ti#e of the opertion nd (b) #etl re#ovl rte fter the drill bit re!hes full di#eter. Solution8 () " () " > > #/? $ > $ > 15(10)/(12.) > rev/#in f r r > "f > "f > > (0.20) > 5.2 ##/#in A > A > 0.5 $ tn $ tn (90 C * /2) /2) > 0.5(12.)tn(90 C 116/2) > .62 ## % m > (d (d A A A A)/ )/ f f r r > > (0 A .62)/5.2 > *(.)' in
(b) ' (b) ' (' > 0.25? $2 f r r > > 0.25(12.) 2(5.2) > 3'20 +,in 21.11 21.11
(@S 1.50 > 0.25? $12 f r r A A 0.25? $22 f r r > > 0.25?( $ 0.25?( $12 A $ A $22 ) f r r 1.50 > 0.25?( 0.5 2 A 0.52 ) f f r r > > 0.6 f r r f r r > > 1.50/0.6 > 2(+' in,in
(b) -or 1/2 in hole, " hole, " > > #/? $ > $ > 00/(0.50?/12) > 2292 rev/#in -or / in hole, " hole, " > > #/? $ > $ > 00/(0.5?/12) > 1526 rev/#in > f > / . -or 1/2 hole, f hole, > f f r r " " f > 2.5/2292 > *(**1* in,rev -or / hole, f hole, f > > 2.5/1526 > *(**1' in,rev :!erpts fro# this "or' #y be reprodu!ed by instru!tors for distribution on notforprofit bsis for testin$ or instru!tionl purposes only to students enrolled in !ourses for "hi!h the tetboo' hs been dopted. Any other reproduction reproduction or translation of this work work beyond that permitted by Sections 107 or 108 of the 1976 United States Copyriht Act without the permission of the copyriht owner is unlawful! 211
Solutions for Fundamentals of Modern Manufacturing , 5/e (published by Wiley) MPGroover 2012
(!) Must use #i#u# llo"n!e for the 2 drills. -or 1/2 in hole, A hole, A > > 0.5 $ tn $ tn (90 C * /2) /2) > 0.5(0.50) tn(90 C 116/2) > 0.150 in -or / in hole, A hole, A > > 0.5 $ tn $ tn (90 C * /2) /2) > 0.5(0.5) tn (90 C 116/2) > 0.225 in % m> (t (t A A A A)/ )/ f f r r > > (1.00 A 0.225)/2.5 > *('22 in 4 +1(2 se5on%s 21.12
(@S / in. here re 100 holes in ll, rrn$ed in 10 by 10 #tri pttern, nd the distn!e bet"een d+!ent d+!ent hole !enters (lon$ the s=ure) s=ure) > 1.5 in. in. 00 00 ft/#in, ft/#in, penetrtio penetrtion n feed ( + dire!tion) dire!tion) > 0.015 in/rev, nd trverse rte bet"een holes ( ,( ,-yy plne) > 15.0 in/#in. ssu#e tht ,tht ,- y #oves re #de t distn!e of 0.50 in bove the "or' surf!e, nd tht this distn!e #ust be in!luded in!luded in in the penetrtion penetrtion feed rte rte for e!h e!h hole. hole. lso, the the rte t "hi!h "hi!h the drill is retr!ted retr!ted fro# e!h hole is t"i!e the penetrtion feed rte. he drill hs point n$le > 100 . *eter#ine the ti#e re=uired fro# the be$innin$ of the first hole to the !o#pletion of the lst hole, ssu#in$ the #ost effi!ient drillin$ se=uen!e is used to !!o#plish the +ob. Solution8 i#e to drill e!h hole8 " > > 00 12/0.5 > 152. rev/#in f r r > > 152.(0.015) > 22.91 in/#in *istn!e per hole > 0.5 A A A A A 1.5 A > A > 0.5(0.5) tn(90 C 100/2) > 0.15 in % m > (0.5 A 0.15 A 1.5)/22.91 > 0.112 #in
i#e to retr!t drill fro# hole > 0.112/2 > 0.05 #in ll #oves bet"een holes re t distn!e > 1.5 in usin$ b!' nd forth pth bet"een ro"s of holes. i#e to #ove bet"een holes > 1.5/15 > 0.1 #in. With 100 holes, the nu#ber of #oves bet"een holes > 99. otl !y!le ti#e to drill 100 holes > 100(0.112 A 0.05) A 99(0.1) > 20(- in 21.1
!A" (@S 000 rev/#in, nd feed > 0.001 in/rev. ;n order to i#prove surf!e finish in the hole, it hs been de!ided to in!rese the speed by 20I nd de!rese the feed by 25I. 3o" lon$ "ill it t'e to perfor# the opertion t the ne" !uttin$ !onditions%
> "f > > 000 rev/#in (0.001 in/rev) > .6 in/#in Solution8 f r r > "f 3ole depth d > > 2.5 #in(.6 in/#in) > 1.0 in 7e" speed speed # > 000(1 A 0.20) > 600 rev/#in 7e" feed feed f > > 0.001(1 0.25) > 0.00125 in/#in 7e" feed feed rte f rte f r r > > 600(0.00125) > .12 in/#in 7e" drillin$ drillin$ ti#e % m > 1.0/.12 in/#in > 2(-. in Millin#
21.1
!A" (S; units) Peripherl #illin$ is perfor#ed on the top surf!e of re!tn$ulr "or' prt tht is 00 ## lon$ by 50 ## "ide. he #illin$ !utter is 0 ## in di#eter nd hs five teeth. ;t overhn$s the "idth of the prt on both sides. 0 #/#in, !hip lod > 0.25 ##/tooth, nd depth of !ut > .5 ##. *eter#ine () #!hinin$ ti#e of the opertion nd (b) #i#u# #teril re#ovl rte durin$ the !ut. Solution8 () " () " > > #/? $ > $ > 0(10) ##/0 > 2 rev/#in f r r > "n > "n f > 2(5)(0.25) > 1 ##/#in t > A > A > (d (d ( $ $d )) ))0.5 > (.5(0.5)) 0.5 > 20. ## % m > (00 A 20.)/1 > 1(2+ in
:!erpts fro# this "or' #y be reprodu!ed by instru!tors for distribution on notforprofit bsis for testin$ or instru!tionl purposes only to students enrolled in !ourses for "hi!h the tetboo' hs been dopted. Any other reproduction reproduction or translation of this work work beyond that permitted by Sections 107 or 108 of the 1976 United States Copyriht Act without the permission of the copyriht owner is unlawful! 211
Solutions for Fundamentals of Modern Manufacturing , 5/e (published by Wiley) MPGroover 2012
(b) ' (b) ' (' > wdf r r > > 50(.5)(1) > 11*3.2' +,in 21.15
(S; units) units) f!e f!e #illin$ #illin$ opertion opertion re#oves .0 ## fro# fro# the top surf!e surf!e of of re!tn$ulr re!tn$ulr pie!e pie!e of lu#inu# tht is 00 ## lon$ by 90 ## "ide by 5 ## thi!'. he !utter follo"s pth tht is !entered over the "or'pie!e. ;t hs four teeth nd is 100 ## in di#eter. 2.0 #/s, nd !hip lod > 0.2 ##/tooth. *eter#ine () #!hinin$ ti#e nd (b) #i#u# #etl re#ovl rte durin$ !uttin$. () " > > #/? $ > $ > 2.0(10) ##/s)/100 > . rev/s Solution8 () " f r r > "n > "n f > .()(0.2) > .66 ##/s t > A
0.5 $
$
2
w
2
>
0.5 100
100
2
90
2
> 0.5(100 C .) > 26.2 ##
% m > ( & & A A)/ A)/ f f r r > > (00 A 26.2))/.66 > )-(- s 4 *(.* in (b) ' (b) ' (' > wdf r r > > 90()(.66) > +-1' +,s 21.1
(@S 125 ft/#in, feed > 0.00 in/tooth, nd depth of !ut > 0.00 in. *eter#ine () #!hinin$ ti#e nd (b) #i#u# #etl re#ovl rte durin$ the !ut. (!) ;f n dditionl ppro!h distn!e of 0.5 in is provided t the be$innin$ be$innin$ of the pss pss (before (before !uttin$ !uttin$ be$ins) be$ins),, nd n n overtrvel overtrvel distn! distn!ee is provide provided d t the the end of of the pss e=ul to the !utter rdius plus 0.5 in, "ht is the durtion of the feed #otion. Solution8 () " () " > #/? $ > $ > 125(12)/ > 159.15 rev/#in f r r > "n > "n f > 159.15(6)(0.00) > . in/#in t > A > A > (d (d ( $ $d )) ))0.5 > (0.0(.00.0)) 0.5 > 0.90 in % m > ( & A & A A A)/ )/ f f r r > > (12.0 A 0.9)/. > 1(0 in
(b) ' (b) ' (' > wdf r r > > 2.5(0.0)(.) > '(-+ in+,in (!) he !utter trvels 0.5 in before #'in$ !ont!t "ith the "or'. ;t #oves 0.90 in before re!hin$ full depth of !ut. ;t then feeds the len$th of the "or' (12.0 in). he overtrvel !onsists of the !utter rdius (1.5 in) plus n dditionl 0.5 in. hus, % f > > (0.5 A 0.9 A 12.0 A 1.5 A 0.5)/. > 2(*2 in 21.1
(@S 250 ft/#in, feed > 0.00 in/tooth, nd depth of !ut > 0.150 in. *eter#ine () #!hinin$ ti#e nd (b) #i#u# #etl re#ovl rte durin$ the !ut. (!) ;f n dditionl ppro!h distn!e of 0.5 in is provided t the be$innin$ be$innin$ of the pss pss (before (before !uttin$ !uttin$ be$ins) be$ins),, nd n n overtrvel overtrvel distn! distn!ee is provide provided d t the the end of of the pss e=ul to the !utter rdius plus 0.5 in, "ht is the durtion of the feed #otion% Solution8 () " () " > > #/? $ > $ > 250(12)/ > 16. rev/#in f r r > > 16.(5)(0.00) > 9.55 in/#in A
0.5 $
$
2
w
2
>
0.5
2
2.0
2
0.62
in
% m > (12.0 A 0.62)/9.55 > 1(+* in (b) ' (b) ' (' > 2.0(0.150)(9.55) > 2(.- in+,in (!) he !utter trvels 0.5 in before #'in$ !ont!t "ith the "or'. ;t #oves 1.50 in before its !enter is li$ned "ith the strtin$ ed$e of the 12.0 in "or'pie!e. ;t then feeds the len$th of the "or' (12.0 in). he overtrvel !onsists of the !utter rdius (1.5 in) plus n dditionl 0.5 in. hus, % f > > (0.5 A 1.5 A 12.0 A 1.5 A 0.5)/9.55 > 1(0. in :!erpts fro# this "or' #y be reprodu!ed by instru!tors for distribution on notforprofit bsis for testin$ or instru!tionl purposes only to students enrolled in !ourses for "hi!h the tetboo' hs been dopted. Any other reproduction reproduction or translation of this work work beyond that permitted by Sections 107 or 108 of the 1976 United States Copyriht Act without the permission of the copyriht owner is unlawful! 211
Solutions for Fundamentals of Modern Manufacturing , 5/e (published by Wiley) MPGroover 2012
21.16
(@S 1.0 in "ide. his is !lled prtil f!e #illin$, -i$ure 21.20(b). Solution8 () " () " > > 250(12)/ > 16. rev/#in f r r > > 16.(5)(0.00) > 9.55 in/#in A
w $
w
1.0 1.0 .0 .0
1.0
> 1.1 in
% m > (12.0 A 1.1)/9.55 > 1()*' in (b) ' (b) ' (' > 1.0(.150)(9.55) > 1()+ in+,in (!) he !utter trvels 0.5 in before #'in$ !ont!t "ith the "or'. ;t #oves 1.1 in before re!hin$ full "idth of !ut. ;t then feeds the len$th of the "or' (12.0 in). he overtrvel !onsists of the !utter rdius (1.5 in) plus n dditionl 0.5 in. hus, % f > > (0.5 A 1.1 A 12.0 A 1.5 A 0.5)/9.55 > 1(0- in 21.19
(@S 5 ft/#in nd !hip lod > 0.00 in/tooth. *eter#ine () #!hinin$ ti#e, (b) ver$e #etl re#ovl rte durin$ the entire !ut, nd (!) #i#u# #etl re#ovl rte. Solution/ () " () " > > #/? $ > $ > 5(12)/? > 56 rev/#in f r r > "n > "n f > 56()(0.00) > . in/#in t > % m > & > &// f f r r > > .9/. > *(0*' in
(b) ' (b) ' ('a#erae 0.25? $2d /% m > 0.25?(.9)2(0.2)/0.05 > 0(+2 in+,in ('a#erae > totl re#oved/totl ti#e > 0.25? $ (!) ' (!) ' ('ma, > point "here the !utter +ust bout !overs the entire !ylinder. ;n this !se it "ould be the s#e s #illin$ re!tn$le so ' (' > wdf r r ' (' > wdf r r > > .9(0.2). > .(*) in+,in 21.20
(S; units) units) he he top surf!e surf!e of re!tn$u re!tn$ulr lr "or' prt is #!hine #!hined d in peripherl peripherl #illin$ #illin$ opertion. opertion. he "or' prt is 5 ## lon$ by 50 ## "ide by 95 ## thi!'. he #illin$ !utter, "hi!h is 5 ## in di#eter nd hs five teeth, overhn$s the "idth of the prt e=ully on both sides. 0 #/#in, !hip lod > 0.20 ##/tooth, nd depth of !ut > .5 ##. () *eter#ine the ti#e re=uired to #'e one pss !ross the surf!e, $iven tht the setup nd #!hine settin$s provide n ppro!h distn!e of 5 ## before !tul !uttin$ be$ins nd n overtrvel distn!e of 25 ## fter !tul !uttin$ hs finished. (b) Wht is the #i#u# #teril re#ovl rte durin$ the !ut% Solution8 () " () " > > #/? $ > $ > 0(10) ##/5 > 29.6 rev/#in f r r > "n > "n f > 29.6(5)(0.20) > 29.6 ##/#in t > A > A > (d (d ( $ $d )) ))0.5 > (.5(5.5)) 0.5 > 20.6 ## % m > (5 A 5 A 20.6 A 25)/29.6 > 2(0- in
(b) ' (b) ' (' > wdf r r > > 50(.5)(29.6) > 11*31-' +,in M$56inin# $n% Turnin# Centers
21.21
!A" threeis !o#puter nu#eri!l !ontrol #!hinin$ !enter is tended by "or'er "ho lods nd unlods prts bet"een #!hinin$ !y!les. he #!hinin$ !y!le t'es 5.5 #in, nd the "or'er t'es 2.60 #in usin$ hoist to unlod the prt +ust !o#pleted nd lod nd fiture the net prt onto the #!hine "or'tble. proposl hs been #de to instll t"oposition pllet shuttle t the #!hine so tht the "or'er nd the #!hine tool !n perfor# their respe!tive ts's si#ultneously rther thn se=uentilly. he pllet shuttle "ould trnsfer the prts bet"een the #!hine "or'tble nd the lod/unlod sttion in 15 se!. *eter#ine () the !urrent !y!le ti#e for the opertion nd (b) the
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Solutions for Fundamentals of Modern Manufacturing , 5/e (published by Wiley) MPGroover 2012
!y!le ti#e if the proposl is i#ple#ented. (!) Wht is the per!ent$e in!rese in hourly produ!tion rte tht "ould result fro# usin$ the pllet shuttle% Solution8 () he !urrent !y!le ti#e is the #!hine !y!le ti#e plus the lod unlod ti#e. % c > 5.5 A 2.60 > .('' in
(b) he !y!le ti#e under the proposl is % c > MB5.5, 2.60D A 0.25 > 0(** in (!) he !urrent hourly produ!tion rte ' p > 0/6.55 > .02 p!/hr he produ!tion rte under the proposl ' p > 0/.0 > 10 p!/hr his is n in!rese of (10 C .02)/.02 > 0.25 > )2('7 21.22 21.22
prt prt is produ!ed produ!ed usin$ si si !onvention !onventionl l #!hine #!hine tools !onsis !onsistin$ tin$ of three three #illin$ #illin$ #!hines #!hines nd three drill presses. he #!hine !y!le ti#es on these #!hines re . #in, 2. #in, 0.6 #in, 0.9 #in, . #in, nd 0.5 #in. he ver$e lod/unlod ti#e for e!h opertion is 1.25 #in. he !orrespondin$ setup ti#es for the si #!hines re 1.55 hr, 2.62 hr, 5 #in, 5 #in, .15 hr, nd #in, respe!tively. respe!tively. he totl #teril hndlin$ ti#e to !rry one prt bet"een the #!hines is 20 #in (!onsistin$ of five #oves bet"een si #!hines). !o#puter !o#puter nu#eri!l !ontrol #!hinin$ !enter hs been instlled, nd ll si opertions "ill be perfor#ed on it to produ!e the prt. he setup ti#e ti#e for the #!hinin$ !enter for this this +ob is 1.0 hr. hr. ;n ddition, the #!hine #ust be pro$r##ed for this prt (!lled (!lled Jprt pro$r##in$K), pro$r##in$K), "hi!h t'es .0 hr. hr. he #!hine !y!le ti#e is the su# of the #!hine !y!le ti#es for the si #!hines. Eod/unlod ti#e is 1.25 #in. () Wht is the totl ti#e to produ!e one of these prts usin$ the si !onventionl #!hines if the totl !onsists of ll setups, #!hine !y!le ti#es, lod/unlod ti#es, nd prt trnsfer ti#es bet"een #!hines% (b) Wht is the totl ti#e ti#e to produ!e one of these prts prts usin$ the <7< #!hinin$ !enter if the totl !onsists of the setup ti#e, pro$r##in$ ti#e, #!hine !y!le ti#e, nd lod/unlod ti#e. Wht re the per!ent svin$s in totl ti#e !o#pred to your ns"er in ()% (!) ;f the s#e prt is produ!ed in bt!h of 20 pie!es, "ht is the totl ti#e to produ!e the# under the s#e !onditions s in () e!ept tht the totl #teril hndlin$ ti#e to !rry the 20 prts in one unit lod bet"een bet"een the #!hines is 0 #in% (d) ;f the prt is produ!ed produ!ed in bt!h of 20 pie!es on the <7< #!hinin$ #!hinin$ !enter, "ht is the totl ti#e to produ!e produ!e the# under the s#e !onditions s in prt (b), nd "ht re the per!ent svin$s in totl ti#e !o#pred to your ns"er in (!)% (e) ;n future orders of 20 pie!es of the s#e prt, the pro$r##in$ ti#e "ill not be in!luded in the totl ti#e be!use the prt pro$r# hs lredy been prepred nd sved. ;n this !se, ho" lon$ does it t'e to produ!e the 20 prts usin$ the #!hinin$ !enter, nd "ht re the per!ent svin$s in totl totl ti#e !o#pred to your your ns"er in (!)% Solution8 () %% > > % su A % m A % & A % (. % su > 0(1.55 A 2.62 A .15) A 5 A 5 A > 569.2 #in % m > . A 2. A 0.6 A 0.9 A . A 0.5 > 12. #in > (1.25 )A 20 > 2.5 #in % & A % (. > %% > > 569.2 A 12. A 2.5 > 29. #in > 10.9 hr
(b) %% > > % pp A % su A % m A % & %% > > 160 A 0 A 12. A 1.25 > 25.65 #in > .2 hr I svin$s > (10.9 C .2)/10.9 > .2/10.9 > 0.59 > 59.I (!) %% > > % su A 20% m A 20% & A % (. % su > 0(1.55 A 2.62 A .15) A 5 A 5 A > 569.2 #in 20% m > 20(. A 2. A 0.6 A 0.9 A . A 0.5) > 20(12.) > 252 #in 20% & A % (. > 20()(1.25) A 0 > 150 A 0 > 190 #in %% > > 569.2 A 252 A 190 > 101.2 #in > 1.19 hr (d) %% > > % pp A % su A 20% m A 20% 20% & :!erpts fro# this "or' #y be reprodu!ed by instru!tors for distribution on notforprofit bsis for testin$ or instru!tionl purposes only to students enrolled in !ourses for "hi!h the tetboo' hs been dopted. Any other reproduction reproduction or translation of this work work beyond that permitted by Sections 107 or 108 of the 1976 United States Copyriht Act without the permission of the copyriht owner is unlawful! 211
Solutions for Fundamentals of Modern Manufacturing , 5/e (published by Wiley) MPGroover 2012
%% > > 160 A 0 A 20(12.) A 20(1.25) > 51 #in > 6.2 hr I svin$s > (1.19 C 6.2)/1.19 > 6.5/1.19 > 0.99 > 9.9I (e) %% > > % su A 20% m A 20% 20% & %% > > 0 A 20(12.) A 20(1.25) > #in > 5.2 hr I svin$s > (1.19 C 5.2)/1.19 > 11.5/1.19 11.5/1.19 > 0. > .I Ot6er O&er$tions
21.2
!A" (S; units) shper is used to redu!e the thi!'ness of 50## !st iron prt to 5 ##. he top surf!e of the prt is 550 ## lon$ by 200 ## "ide. 0.125 #/se!, nd feed > 0.50 ##/pss. he shper r# is hydruli!lly driven nd hs return stro'e ti#e tht is 50I of the !uttin$ stro'e ti#e. n etr 100 ## #ust be dded before nd fter the prt for !!elertion nd de!elertion to t'e pl!e. ssu#in$ the r# #oves prllel to the lon$ di#ension of the prt, ho" lon$ "ill it t'e to #!hine% Solution8 i#e per for"rd stro'e > (100 A 550 A 100)/(0.125 1000) > .0 se! i#e per reverse stro'e > 0.50(.0) > .0 se! otl ti#e per pss > A > 9 se! > 0.15 #in 7u#ber of psses psses > 200/0.5 200/0.50 0 > 500 500 psses psses otl ti#e % m > 500(0.15) > -' in
21.2
(@S 0 ft/#in, feed > 0.015 in/pss, nd depth of !ut > 0.250 in. he len$th of the stro'e !ross the "or' #ust be set up so tht 10 in re llo"ed t both the be$innin$ nd end of the stro'e for ppro!h nd overtrvel. he return stro'e, in!ludin$ n llo"n!e for !!elertion nd de!elertion, t'es 0I of the ti#e for the for"rd stro'e. 3o" lon$ "ill it t'e to !o#plete the +ob, ssu#in$ tht the prt is oriented in su!h "y s to #ini#iLe the ti#e% Solution8 rient the prt so tht its len$th ( & ( & > > 5 in) is in the dire!tion of the stro'e. his "ill #ini#iLe the nu#ber of psses re=uired "hi!h "ill #ini#iLe ti#e in this !se. i#e per for"rd stro'e > (10 A 5 A 10)/(0 12) > 0.16 #in i#e per reverse stro'e > 0.0(.16) > 0.11 #in otl ti#e per pss > 0.16 A 0.11 > 0.29 #in 7u#ber of psses psses > 20.0/0 20.0/0.015 .015 > 1 1 psses psses otl ti#e % m > 1(0.29) > +.- in C6e58 8 orient "or' so tht its "idth ( w > 20 in) is in dire!tion of stro'e. i#e per for"rd stro'e > (10 A 20 A 10)/(0 12) > 0.11 #in i#e per reverse stro'e > 0.0(.11) > 0.0 #in otl ti#e per pss > 0.11 A 0.0 > 0.1 #in 7u#ber of psses psses > 5.0/0 5.0/0.015 .015 > 000 000 psses psses otl ti#e > 000(0.1) > '+1 in
21.25 21.25
(S; units units)) 3i$hspeed 3i$hspeed #!hini #!hinin$ n$ is bein$ !onside !onsidered red to produ!e produ!e the lu#inu# lu#inu# prt in Proble# Proble# 21.15. ll !uttin$ !onditions !onditions re#in the s#e e!ept for the !uttin$ speed nd the type of insert used in the !utter. !utter. ssu#e the !uttin$ speed "ill be t the li#it $iven in ble 21.1. *eter#ine () the ne" ti#e to #!hine the prt nd (b) the ne" #etl re#ovl rte. (!) ;s this prt $ood !ndidte for hi$hspeed #!hinin$% # !hinin$% :plin. Solution/ ssu#e the s#e indeble tool (f!e #ill "ith pproprite inserts) "ill be used in the ne" opertion. -or lu#inu#, the 3SM !uttin$ speed "ill be ,00 #/#in fro# ble 21.1.
() " () " > > #/? $ > $ > (00(10 ) ##/#in)/(100 ##/rev) > 11,59 rev/#in :!erpts fro# this "or' #y be reprodu!ed by instru!tors for distribution on notforprofit bsis for testin$ or instru!tionl purposes only to students enrolled in !ourses for "hi!h the tetboo' hs been dopted. Any other reproduction reproduction or translation of this work work beyond that permitted by Sections 107 or 108 of the 1976 United States Copyriht Act without the permission of the copyriht owner is unlawful! 211
Solutions for Fundamentals of Modern Manufacturing , 5/e (published by Wiley) MPGroover 2012
f r r > "n > "n f > 11,59()(0.2) > 12, ##/#in > 20. ##/s t > A
0.5 $
$
2
w
2
>
0.5 100
100
2
90
2
> 0.5(100 C .) > 26.2 ##
> (00 A 26.2)/20. > 1(- se5 % m > ( &A &A A)/ A)/ f f r r > (b) ' (b) ' (' > wdf r r > > 90()(20.) > 1113)** +,se5 (!) his is probbly not $ood !ndidte be!use the # !hinin$ ti#e is so s#ll nd it is sin$le, si#ple$eo#etry opertion. opertion. he ti#e to lod nd unlod the prt "ill be #u!h lon$er thn the #!hinin$ ti#e nd the #!hine "ill be idle "hile tht is hppenin$. Generlly, Generlly, 3SM is +ustified by t lest one of the follo"in$ follo"in$ !onditions8 !onditions8 (1) lr$e volu#es volu#es of #etl re#oved fro# lr$e prts, prts, (2) #ultiple !uttin$ opertions re=uirin$ #ny different tools, nd () !o#ple shpes.
:!erpts fro# this "or' #y be reprodu!ed by instru!tors for distribution on notforprofit bsis for testin$ or instru!tionl purposes only to students enrolled in !ourses for "hi!h the tetboo' hs been dopted. Any other reproduction reproduction or translation of this work work beyond that permitted by Sections 107 or 108 of the 1976 United States Copyriht Act without the permission of the copyriht owner is unlawful! 211
