,transcrib]'s ,notes3 ,und]scores 80 be=e & aft] a ^w or phrase indicate italics 9 ! orig9al text4 ,equal signs 80 be=e & aft] a ^w or phrase indicate bold 9 ! orig9al text4 ,small capitals h be5 conv]t$ to ,,solid capitals4 ,illu/rations h be5 mov$ s !y d n break up p>agraphs4 ,typographical & punctuation errors h be5 sil5tly correct$4 ,,ma*9]y',s ,,ref]5ce ,,s]ies ,,ea* ,,numb] ,,is ,,"o ,,unit ,,9 ,a ,,complete ,,libr>y ,,( ,,ma*9e ,,design ,,& ,,%op ,,practice ,,revis$ ,,& ,,republi%$ ,,f ,,ma*9]y ,,numb] #ace ,,precision ,,locat+ ,,& ,,divid+ ,,me?ods ,,cont5ts ,precision ,locat+ ,me?ods #c ,accurate ,divid+ & ,spac+ ,me?ods #ba ,locat+ ,"w = ,bor+ on ,mill+ ,ma*9e #cb ,copyright1 #aiad1 ,! ,indu/rial ,press1 ,publi%]s ( ,,ma*9]y1 #adj-adh ,lafayette ,/reet1 ,new ,york ,city ,o!r books 9 ?is s]ies deal+ ) ! subjects ( ,toolmak+ & k9dr$ topics are z foll[s3 ,no4 #ca--,,?read ,,tools ,,& ,,gages ,no4 #fd--;,,gage ,,mak+ ,,& ,,lapp+ ,no4 #ajg--;,,drop ,,=g+ ,,die ,,s9k+ ,no4 #acj--;,,gag+ ,,tools ,,& ,,me?ods ,illu/ration3 ,,ma*9]y ,,ma*9]y ,! ,lead+ ,me*anical ,j\rnal ,,ma*9e ,,design ,,con/ruction ,,%op ,,practice ,,! ,,indu/rial ,,press #adj-adh ,lafayette ,/4 ,new ,york ,city #ea-eb ,*anc]y ,lane1 ,london ,,*apt] ,i ,,precision ,,locat+ ,,me?ods ,! degree ( accuracy t is necess>y 9 ! con/ruction ( c]ta9 classes ( ma*9]y & tools1 has made x necess>y = toolmak]s & ma*9i/s to employ v>i\s me?ods & appliances = locat+ holes or f9i%$ surfaces to giv5 dim5sions & )9 ! prescrib$ limits ( accuracy4 ,9 ?is treatise1 v>i\s approv$ me?ods ( locat+ "w1 su* z are us$ m p>ticul>ly 9 tool-rooms1 are describ$ & illu/rat$4 ,^! are n giv51 9 e case1 z be+ ! be/ possible me?od "u all conditions1 because1 z e me*anical man kn[s1 ! be/ way may be dep5d5t ^u ! elem5t ( accuracy ) little reg>d = ! "t requir$ to d ! "w1 or ?is ord] may be rev]s$2 !re=e1 "o me?od is seldom1 if ev]1 ! be/ "u all circum/ances1 & x is necess>y = ! workman to consid] ! conditions 9 ea* case & !n be guid$ by 8 judgm5t & exp]i5ce 9 det]m9+ j h[ ! "w %\ld be done4 ,button ,me?od ( ,accurately ,locat+ ,"w ,among ! diff]5t me?ods employ$ by toolmak]s = accurately locat+ "w su* z jigs1 etc41 on ! faceplate ( a la!1 "o ( ! mo/ commonly us$ is kn[n z ! 8button me?od40 ,?is me?od is s nam$ because cyl9drical bu%+s or buttons are atta*$ to ! "w 9 positions correspond+ to ! holes to be bor$1 aft] :i* !y are us$ 9 locat+ ! "w4 ,^! buttons :i* are ord9>ily ab\t or in* 9 diamet]1 are gr\nd & lapp$ to ! same size1 & ! ends are f9i%$ p]fectly squ>e4 ,! outside diamet] %\ld pref]ably be su* t ! radius c easily be det]m9$1 & ! hole ?r\gh ! c5t] %\ld be ab\t in* l>g] ?an ! reta9+ screw s t ! button c be adju/$ lat]ally4 ,z a simple example ( ! practical application ( ! button me?od1 suppose ?ree holes are to be bor$ 9 a jig-plate accord+ to ! dim5sions giv5 9 ,fig4 #a4 ,a common me?od ( proc$ure w\ld be z foll[s3 ,fir/ lay out ! c5t]s ( all holes to be bor$1 by ! usual me?od4 ,m>k ^! c5t]s ) a prick-pun* & !n drill holes = ! ma*9e screws :i* are us$ to clamp ! buttons4 ,aft] ! buttons are clamp$ lightly 9 place1 set !m 9 correct relation ) ea* o!r & ) ! jig-plate4 ,! prop] location ( ! buttons is v important1 z _! positions l>gely det]m9e ! accuracy ( ! "w4 ,! be/ me?od ( locat+ a numb] ( buttons dep5ds1 to "s ext5t1 ^u _! relative positions1 ! in/rum5ts available1 & ! accuracy requir$4 ,:5 buttons mu/ be locat$ at giv5 di/ances f ! f9i%$ sides ( a jig1 a surface plate & v]ni] height gage are (t5 us$4 ,! me?od is to place t side f :i* ! button is to be set1 ^u an accurate surface plate & !n set ! button by means ( ! height gage1 all[ance be+ made1 ( c\rse1 = ! radius ( ! button4 ,! c5t]-to-c5t] di/ance betwe5 ! diff]5t buttons c aft]w>ds be v]ifi$ by tak+ direct measurem5ts ) a micromet]4 ,illu/ration3 ,fig4 #a4 ,simple ,example ( ,"w ,illu/rat+ ,application ( ,button ,me?od ,figs4 #b & #c illu/rate a me?od :i* requires only a micromet]4 ,two ( ! buttons are set at ! correct di/ance f "o edge ( ! plate by measur+ f a p>allel /rip4 ,obvi\sly1 ! micromet] read+ w exce$ ! di/ance f ! c5t] ( a button to ! edge ( ! plate1 by ! am\nt equal to ! ?ickness ( ! p>allel /rip plus ! radius ( ! button4 ,! c5t]-to-c5t] di/ance betwe5 ea* pair ( buttons is also te/$ z indicat$ 9 ,fig4 #c1 by measur+ ! ov]all di/ance & d$uct+ ! diamet] ( "o button4 ,aft] ! buttons h be5 set & ! screws are tight5$1 all measurem5ts %\ld be c>efully *eck$4 ,! "w is !n m\nt$ on ! faceplate ( ! la! & "o ( ! buttons is set true by ! use ( a te/ indicator z %[n 9 ,fig4 #d4 ,:5 ! dial ( ! indicator ceases to vibrate1 ?us %[+ t ! button runs true1 ! latt] %\ld be remov$ s t ! hole c be drill$ & bor$ to ! requir$ size4 ,9 a simil> mann] o!r buttons are indicat$ & ! holes bor$1 "o at a "t4 ,x is evid5t t if ea* button is correctly locat$ & set p]fectly true 9 ! la!1 ! v>i\s holes w be locat$ ! requir$ di/ance ap>t )9 v close limits4 ,illu/ration3 ,fig4 #b4 ,det]m9+ ,di/ance f ,button to ,edge ( ,plate ,ano!r example ( "w illu/rat+ ! application ( ! button me?od is %[n 9 ,fig4 #e4 ,! disk-%ap$ "p illu/rat$ is a flange templet :i* =m$ a "p ( a fixture = drill+ holes 9 flang$ plates1 ! holes be+ locat$ on a circle #f in*es 9 diamet]4 ,x 0 necess>y to space ! six holes equi-di/antly s t ! holes 9 ! flanges w\ld mat* 9 any position1 ?us mak+ !m int]*angeable4 ,fir/ a plug 0 turn$ s t x fitt$ snugly 9 ! #a-;in* c5tral hole ( ! plate & project$ above ! top surface ab\t in*4 ,a c5t] 0 locat$ 9 ?is plug & f x a circle ( ?ree in*es radius 0 drawn4 ,?is circle 0 divid$ into six equal p>ts & !n small circles in* 9 diamet] 7 drawn to indicate ! outside circumf]5ce ( ! bu%+s to be plac$ 9 ! holes4 ,^! circles s]v$ z a guide :5 sett+ ! button & enabl$ ! "w to be done mu* m quickly4 ,! c5t]s ( ! holes 7 next c>efully prick-pun*$ & small holes 7 drill$ & tapp$ = ,no4 #aj ma*9e screws4 ,aft] ?is ! six buttons 7 atta*$ 9 approximately ! correct positions & ! screws tight5$ en\gh to hold ! buttons firmly1 b all[ !m to be mov$ by tapp+ lightly4 ,z ! radius ( ! circle is #c in*es1 ! radius ( ! c5tral plug1 in*1 & t ( ea* button1 _/ in*1 ! di/ance f ! outside ( ! c5tral plug to ! outside ( any button1 :5 correctly set1 mu/ be #c _/ in*es4 ,s9ce !re are six buttons ar\nd ! circle1 ! c5t]-to-c5t] di/ance is equal to ! radius1 & ! di/ance betwe5 ! outside or any two buttons %\ld be #c in*es4 ,hav+ det]m9$ ^! dim5sions1 ea* button is set equi-di/ant f ! c5tral plug & ! requir$ di/ance ap>t1 by us+ a micromet]4 ,z ea* button is br\ght into its correct position1 x %\ld be tight5$ d[n a little s t x w be locat$ firmly :5 f9ally set4 ,! "w is !n /rapp$ to ! faceplate ( a la! & ea* button is indicat$ = bor+ ! diff]5t holes by means ( an indicator1 z previ\sly describ$4 ,:5 ! buttons are remov$ x w be f\nd t 9 ne>ly all cases ! small screw holes w n run exactly true2 !re=e1 x is advisable to =m a true />t+ po9t = ! drill by us+ a la! tool4 ,illu/ration3 ,fig4 #c4 ,te/+ ,location ( ,buttons ,fig4 #g %[s a me?od ( locat+ buttons f ! f9i%$ sides ( a plate1 & ?is same plate ) ! five buttons atta*$ is %[n 9 ,fig4 #f4 ,z ! dim5sions 9 ,fig4 #g indicate1 ! holes mu/ n only be accurate ) relation to ea* o!r1 b also ) ref]5ce to ! edges ( ! templet2 !re=e1 x is necess>y to "w f ! sides z well z ! c5t]4 ,! wid? ( ! plate 0 fir/ measur$ c>efully & f\nd to be #e in*es4 ,z ! c5t]-to-c5t] di/ance betwe5 buttons ,b & ,c & also buttons ,d & ,e1 is #b in*es1 ! di/ance f ! c5t] ( ea* outside button to ! edge ( ! plate is #a in*4 ,a -in* p>allel 0 clamp$ aga9/ ! side1 z %[n 9 ! illu/ration1 & !n ! di/ance f ! outside ( ea* button to ! outside ( ! p>allel 7#a _/ in*7 0 measur$ 9 conjunction ) ! di/ance ,l f ! c5tral button4 ,! di/ance ,l 0 obta9$ by fir/ det]m9+ ! c5t]-to-c5t] di/ance ,m :i* repres5ts ! hypot5use ( a "r-angl$ triangle4 ,m #a4be #a4fbe or ,m #a4be #a4fbe #d4jbd #b4jej in*es4 ,!re=e1 ,l #b4jej #j4fbe #b4fge in*es4 ,9 ?is case1 ! c5t] button 0 fir/ locat$ correctly f ! sides & end & !n ! o!r buttons 7 set4 ,:5 do+ precision "w ( ?is k9d1 ! degree ( accuracy obta9$ w dep5d ^u ! in/rum5ts us$1 ! judgm5t & skill ( ! workman1 & ! c>e ex]cis$4 ,a good g5]al rule to foll[ :5 locat+ bu%+s or buttons is to use ! me?od :i* is ! mo/ direct & :i* requires ! lea/ numb] ( measurem5ts1 9 ord] to prev5t an accumulation ( errors4 ,locat+ ,"w by ! ,disk ,me?od ,comp>atively small precision "w is sometimes locat$ by ! disk me?od1 :i* is ! same 9 pr9ciple z ! button me?od1 ! *ief diff]5ce be+ t disks are us$ in/ead ( buttons4 ,^! disks are made to su* diamet]s t :5 _! p]iph]ies are 9 contact1 ea* disk c5t] w co9cide ) ! position ( ! hole to be bor$2 ! c5t]s are !n us$ = locat+ ! "w4 ,to illu/rate ?is me?od1 suppose t ! ma/]-plate %[n at ! left 9 ,fig4 #h is to h ?ree holes a1 b1 & c bor$ into x1 to ! c5t] di/ances giv54 ,illu/ration3 ,fig4 #d4 ,te/+ ,conc5tricity ( ,button ,prep>atory to ,bor+ ,hole 9 ,la! ,x is fir/ necess>y to det]m9e ! diamet]s ( ! disks4 ,if ! c5t] di/ances betwe5 all ! holes 7 equal1 ! diamet]s w\ld1 ( c\rse1 equal ?is dim5sion4 ,:51 h[ev]1 ! di/ances betwe5 ! c5t]s are unequal1 ! diamet]s may be f\nd z foll[s3 ,subtract1 say1 dim5sion y f x1 ?us obta9+ ! diff]5ce betwe5 ! radii ( disks ,c & ,a 7see "r-h& sket*72 add ?is diff]5ce to dim5sion z1 & ! result w be ! diamet] ( disk ,a4 ,divid+ ?is diamet] by #b gives ! radius1 :i*1 subtract$ f c5t] di/ance x equals ! radius ( ,b2 simil>ly ! radius ( ,b subtract$ f dim5sion y equals ! radius ( ,c4 ,= example1 #j4icj-j4gbj #j4baj or ! diff]5ce betwe5 ! radii ( disks ,c & ,a4 ,!n ! diamet] ( ,a #j4baj #j4hfj #a4jgj in*1 & ! radius equals #a4jgj #b #j4ece in*4 ,! radius ( ,b #j4icj-j4ece #j4cie in* & #j4cie #b #j4gij1 or ! diamet] ( ,b4 ,! c5t] di/ance #j4gbj-j4cie #j4cbe1 :i* is ! radius ( ,c2 #j4cbe #b #j4fej or ! diamet] ( ,c4 ,illu/ration3 ,fig4 #e4 ,flange ,templet ) ,buttons ,atta*$ ,illu/ration3 ,fig4 #f4 ,h+e ,jig ,templet ) ,buttons ,atta*$ ,aft] det]m9+ ! diamet]s1 ! disks %\ld be turn$ ne>ly to size & f9i%$1 pref]ably 9 a b5* la!4 ,fir/ ins]t a sold] *uck 9 ! sp9dle1 face x p]fectly true1 & atta* ! disk by a few drops ( sold]1 be+ c>eful to hold ! "w firmly aga9/ ! *uck :ile sold]+4 ,face ! out] side & cut a %>p ,v-c5t] 9 x2 !n gr9d ! p]iph]y to ! requir$ diamet]4 ,next fa/5 ! f9i%$ disks onto ! "w 9 _! correct locations ) _! p]iph]ies 9 contact1 & !n set "o ( ! disks exactly c5tral ) ! la! sp9dle by apply+ a te/ indicator to ! c5t] 9 ! disk4 ,aft] remov+ ! disk & bor+ ! hole1 ! "w is locat$ = bor+ ! o!r holes 9 ! same mann]4 ,illu/ration3 ,fig4 #g4 ,h+e ,jig ,templet ,illu/rat$ 9 ,fig4 #f ,small disks may be secur$ to ! "w by means ( jewel]'s wax4 ,?is is compos$ ( common ros9 & pla/] ( p>is & is made z foll[s3 ,heat ! ros9 9 a vessel until x fl[s freely1 & !n add pla/] ( p>is & keep /irr+ ! mixture4 ,c>e %\ld be tak5 n to make ! mixture too /iff4 ,:5 x appe>s to h ! prop] consi/5cy1 p\r "s ( x onto a slate or m>ble slab & all[ x to cool2 !n ins]t ! po9t ( a knife "u ! flatt5$ cake ?us =m$ & try to pry x (f4 ,if x spr+s (f ) a slight metallic r+1 ! proportions are "r1 b if x is gummy & ductile1 !re is too mu* ros94 ,on ! o!r h&1 if x is too brittle & crumbles1 ?is indicates t !re is too mu* pla/] ( p>is4 ,! wax %\ld be w>m$ be=e us+4 ,a mixture ( beeswax & %ellac1 or beeswax & ros9 9 ab\t equal proportions1 is also us$ = hold+ disks 9 place4 ,:5 ! latt] are fairly l>ge1 x may be advisable to secure !m ) small screws1 provid$ ! screw holes are n objectionable4 ,disk-&-,button ,me?od ( ,locat+ ,holes ,! accuracy ( "w done by ! button me?od previ\sly describ$ is limit$ only by ! skill & pa9/ak+ c>e ( ! workman1 b sett+ ! buttons requires a great deal ( "t4 ,by a little modification1 us+ :at is sometimes call$ ! 8disk-&-button me?od10 a l>ge "p ( ?is "t c be sav$ )\t any sacrifice ( accuracy4 ,! disk-&-button me?od is ext5sively us$ 9 _m %ops4 ,buttons are us$1 b !y are locat$ 9 ! c5t]s ( disks ( :atev] diamet]s are necess>y to give ! requir$ locations4 ,z ?ree disks are us$ 9 ea* /ep ( ! process1 x is sometimes call$ ! 8?ree-disk me?od40 ,to illu/rate ! practical application ( ?is me?od1 suppose six equally-spac$ holes are to be locat$ 9 ! circumf]5ce ( a circle six in*es 9 diamet]4 ,to locate ^!1 "o ne$s1 besides ! buttons1 ?ree disks ?ree in*es 9 diamet]1 ea* hav+ a c5tral hole exactly fitt+ ! buttons4 ,x is be/ to h1 also1 a bu%+ ( ! same diamet] z ! buttons1 :i* has a c5t]-pun* fitt$ to slide 9 x4 ,fir/ ! c5t] button is screw$ to ! templet1 & "o ( ! disks ,a1 ,fig4 #i1 is slipp$ ov] x2 !n a second disk ,b c>ry+ a bu%+ & c5t]-pun* is plac$ 9 contact ) disk ,a & a light bl[ on ! pun* m>ks ! place to drill & tap = ,no4 #b button1 :i* is kept 9 its prop] place :ile tight5+ ! screw by hold+ ! two disks ,a & ,b 9 contact4 ,next ! ?ird disk ,c is plac$ 9 contact ) disks ,a & ,b & locates ,no4 #c button1 & s on until ! sev5 buttons are secur$ 9 position4 ,! templet is !n ready to be /rapp$ to ! la! faceplate = bor+4 ,illu/ration3 ,fig4 #h4 ,an ,example ( ,precision ,"w1 & ,me?od ( ,locat+ ,holes by ,use ( ,disks 9 ,contact ,( c\rse1 x is n possible to use disks ( 8/&>d0 sizes = _m op]ations1 b mak+ a special disk is easy1 & its co/ is insignificant z comp>$ ) ! "t sav$ by its use4 ,"o :o employs ?is me?od1 especially if he also uses disks to lay out angles1 soon accumulates a /ock ( v>i\s sizes4 ,:ile x is desirable to h disks ( tool /eel1 h>d5$ & gr\nd1 or1 9 ! l>g] sizes1 ( ma*9e /eel1 case-h>d5$ & gr\nd1 a disk = occasional use w be entirely satisfactory if left s(t4 ,ano!r example ( "w is %[n 9 ,fig4 #aj4 ,?is is a jig templet simil> to ! "o illu/rat$ 9 ,figs4 #f & #g4 ,sket* ,a gives its dim5sions & sket* ,b %[s ! disk-&-button way ( locat+ ! holes4 ,a /eel squ>e is clamp$ ) its /ock aga9/ ! "r-h& edge ( ! templet & its blade ext5d+ across ! top4 ,! l[] edge ( ! blade %\ld be locat$ #j4bej in* f ! upp] edge ( ! templet by ! use ( size blocks4 ,a #b-;in* disk1 t\*+ bo? blade & /ock1 locates hole ,c4 ,ano!r #b-;in* disk1 t\*+ ! fir/ disk & ! squ>e blade1 locates hole ,b4 ,next a disk #a4fjj in* diamet] is plac$ 9 contact ) ! two upp] disks & locates ! c5t] hole ,a2 &1 f9ally1 ! disks = holes ,b & ,c are us$ to locate holes ,d & ,e4 ,illu/ration3 ,fig4 #i4 ,locat+ ,holes on a ,circle & ,equi-di/ant by us+ ,disks & ,buttons 9 ,comb9ation ,two o!r jobs t illu/rate ?is me?od may be ( int]e/4 ,! fir/ "o1 %[n 9 ,fig4 #aa1 requir$ ! locat+ ( n9e equally-spac$ holes on a circumf]5ce ( #g in*es diamet]4 ,9 any su* case1 ! size ( ! small] disks is f\nd by multiply+ ! diamet] ( ! circle ^u :i* ! c5t]s ( ! disks are locat$ by ! s9e ( half ! angle betwe5 two adjac5t disks4 ,! angle betwe5 ! c5t]s ( adjac5t disks equals #cfj numb] ( disks4 #cfj #i #dj2 h5ce1 9 ?is case1 ! diamet] ( ! small] disks equals #g multipli$ by ! s9e ( #bj degrees1 or #g #j4cdbjb #b4ebbd in*es4 #g-b4ebbd #d4hebf in*es1 :i* is ! diamet] ( ! c5tral disk4 ,! templet %[n 9 ,fig4 #ab requir$ two holes on a circumf]5ce #f in*es diamet]1 ) _! c5t]s #cg degrees #bj m9utes ap>t4 ,to f9d ! diamet] ( ! small] disks1 multiply ! diamet] ( ! l>ge circle by ! s9e ( "o-half ! requir$ angle1 z 9 ! prec$+ example2 ?us #f s9 #ah degrees #dj m9utes #b4jhjd in*es1 :i* is ! diamet] ( ! two small] disks4 ,! diamet] ( ! l>g] disk equals #f-b4jhjd #d4daif in*es4 ,v accurate results c be obta9$ by ! disk-&-button me?od4 ,( c\rse1 absolute exactness is equally unatta9able ) buttons & a micromet]1 or any o!r me?od2 ! micromet] does n %[ ! slight inaccuracy 9 any "o *ordal measurem5t1 :ile 9 us+ ! disks ! error is accumulative & ! ins]tion ( ! la/ disk 9 ! s]ies %[s ! sum ( ! errors 9 all ! disks4 ,x is only 9 cases l ! "o illu/rat$ 9 ,fig4 #i t we note ?is1 & !n1 ?\gh 9 correct+ ! error1 we may *ange ! diamet] ( ! circle a v slight am\nt1 an exce$+ly accurate division ( ! circumf]5ce is secur$4 ,use ( ,two- & ,?ree-,diamet] ,disks ,fig4 #ac illu/rates1 on an enl>g$ scale1 a piece ( "w requir+ great accuracy1 :i* 0 successfully h&l$ by an ext5sion ( ! ?ree-disk me?od4 ,f\rte5 holes 7 requir$ 9 a space h>dly l>g] ?an a silv] half-doll>1 &1 al?\gh ! draw+ gave dim5sions f ! c5t] ( ! circle1 ! actual c5t] c\ld n be us$ 9 do+ ! "w1 z !re 0 to be no hole !re2 moreov]1 a boss slightly (f c5t] prev5t$ ! use ( a c5tral disk1 unless ! bottom ( ! disk 7 bor$ out to receive ?is boss1 :i* 0 n ?\ght exp$i5t4 ,h5ce1 ! me?od adopt$ 0 to make ! plate ?ick] ?an ! dim5sion giv5 on ! draw+1 & !n bore x out to leave a rim ( def9ite diamet]1 ?is rim to be remov$ aft] x _h s]v$ its purpose z a locat+ limit = ! disks4 ,illu/ration3 ,fig4 #aj4 7,a7 ,lay\t ( ,jig-,plate4 7,b7 ,disk-&-,button ,me?od ( ,locat+ ,holes ,z ! holes ,a & ,b1 :i* 7 f9i%$ fir/1 7 #j4fjj in* ap>t & #j4fbe in* f ! c5t]1 ! rim 0 bor$ to #a4hej in* & two #j4fjj-;in* disks1 9 contact ) ! rim & ) ea* o!r1 locat$ ^! holes4 ,z hole ,c 0 to be equi-di/ant f holes ,a & ,b1 & its di/ance f ! c5t] 0 giv51 ! size ( ! disk = ?is hole 0 readily det]m9$4 ,! disks = holes ,a1 ,b & ,c h two diamet]s2 ! upp] diamet]s are made to :atev] size is requir$ = locat+ ! disks ( adjac5t holes1 & !y also =m a hub :i* c be us$ :5 sett+ ! disks ) an indicator4 ,hole ,d 0 #j4dbai in* f ,b1 & calculations bas$ on ?is dim5sion & its di/ance f ! c5t] %[$ t x 0 #j4dcge in* f hole ,c4 ,a 8?ree-/ory0 disk or button 0 made = hole ,d4 ,! diamet] ( ! l>ge "p 0 #j4dfhge in* & x ov]lapp$ disks ,c & ,b 7! upp] sections ( :i* 7 made #j4cge in* & #j4djfb in*1 respectively71 ?us locat+ ,d4 ,!n hole ,f & all ! rema9+ holes 7 locat$ 9 a simil> mann]4 ,! upp] diamet]s ( disks ,e & ,d 7 us$ 9 locat+ disks = o!r adjac5t holes1 z well z a hub = ! indicator2 = in/ance1 to locate a hole ) ref]5ce to holes ,c & ,d1 ! diamet] ( ! new disk & ! diamet] ( ! upp] "p ( disk ,d1 7 v>i$ to give ! requir$ location4 ,! relation betwe5 ! disks ,b1 ,d & ,f is %[n by ! side view4 ,illu/ration3 ,fig4 #aa4 ,example ( ,circul> ,spac+ requir+ a ,l>ge ,c5tral ,disk ,x _h be5 decid$ t no screws %\ld be us$ 9 atta*+ ! buttons or disks to ! "w1 z x 0 fe>$ t ! tapp$ holes w\ld introduce inaccuracy by deflect+ ! bor+-tools2 !re=e ! foll[+ me?od 0 employ$4 ,aft] all ! disks 7 fa/5$ 9 place by clamps1 a s(t sold] ( l[ melt+ po9t 0 fl[$ ab\t !m1 fill+ ! "w to ! top ( ! rim4 ,:5 ! sold] _h cool$1 ! clamps 7 remov$1 ! "w transf]r$ to ! la! faceplate1 indicat$ 9 ! usual way1 & ! holes bor$ by a 8,d0 or 8hog-nose0 drill1 guid$ by an axial hole 9 ea* disk1 :i* _h be5 provid$ = t purpose :5 ! disks 7 made4 ,x 0 ?\ght t ! unequal contraction ( ! sold] & ! plate 9 cool+ might ?r[ ! holes 8out ( squ>e20 h[ev]1 c>eful measurem5ts fail$ to %[ any appreciable lack ( p>allelism 9 te/-b>s ins]t$ 9 ! holes4 ,illu/ration3 ,fig4 #ab4 ,locat+ ,holes at an ,angle by use ( ,disks & ,buttons ,illu/ration3 ,fig4 #ac4 ,locat+ ,holes by ,means ( ,two- & ,?ree-,diamet] ,disks 9 ,contact ,accurate ,angul> ,measurem5ts ) ,disks ,= sett+ up a piece ( "w on :i* a surface is to be plan$ or mill$ at an exact angle to a surface already f9i%$1 disks provide an accurate means ( adju/m5t4 ,"o me?od ( us+ disks = angul> "w is illu/rat$ at ,a 9 ,fig4 #ad4 ,let u assume t ! l[] edge ( plate %[n is f9i%$ & t ! upp] edge is to be mill$ at an angle a ( #cb degrees ) ! l[] edge4 ,if ! two disks x & y are to be us$ = locat+ ! "w1 h[ f> ap>t mu/ !y be set 9 ord] to locate x at ! requir$ angle8 ,! c5t]-to-c5t] di/ance c be det]m9$ z foll[s3 ,subtract ! radius ( ! l>g] disk f ! radius ( ! small] disk1 & divide ! diff]5ce by ! s9e ( "o-half ! requir$ angle4 ,illu/ration3 ,fig4 #ad4 ,obta9+ ,accurate ,angul> ,measurem5ts ) ,disks ,example3 ,if ! requir$ angle a is #cb degrees1 ! radius ( ! l>ge disk1 #b in*es1 & ! radius ( ! small disk1 #a in*1 :at is ! c5t]-to-c5t] di/ance8 ,! s9e ( "o-half ! requir$ angle1 or #af degrees1 is #j4bgefd4 ,! diff]5ce betwe5 ! radii ( ! disks equals #b - #a #a1 & #a #j4bgefd #c4fbd in*es4 ,!re=e1 = an angle ( #cb degrees1 disks ( ! sizes giv5 %\ld be set s t ! di/ance betwe5 _! c5t]s is #c4fbd in*es4 ,ano!r me?od ( accurately locat+ angul> "w is illu/rat$ at ,b 9 ,fig4 #ad4 ,9 ?is case1 two disks are also us$1 b !y are plac$ 9 contact ) ea* o!r & *anges = diff]5t angles are obta9$ by v>y+ ! diamet] ( ! l>g] disk4 ,! small] disk is a /&>d #a-;in* size1 su* z is us$ = sett+ a #b-;in* micromet]4 ,by ?is me?od any angle up to ab\t #dj degrees c be obta9$ )9 a v close limit ( accuracy4 ,! foll[+ rule may be us$ = det]m9+ ! diamet] ( ! l>g] disk1 :5 bo? disks are 9 contact & ! diamet] ( ! small disk is kn[n3 ,multiply twice ! diamet] ( ! small disk by ! s9e ( "o-half ! requir$ angle2 divide ?is product by #a m9us ! s9e ( "o-half ! requir$ angle2 add ! quoti5t to ! diamet] ( ! small disk to obta9 ! diamet] ( ! l>ge disk4 ,example3 ,! requir$ angle a is #ae degrees4 ,f9d ! diamet] ( ! l>ge disk to be 9 contact ) ! /&>d #a-;in* ref]5ce disk4 ,! s9e ( #g degrees #cj m9utes is #j4acjec4 ,multiply+ twice ! diamet] ( ! small disk by ! s9e ( #g degrees #cj m9utes1 we h #b #a #j4acjec #j4bfajf4 ,?is product divid$ by #a m9us ! s9e ( #g degrees #cj m9utes #j4bfajf ---------------------- #c4jjb4 #a - #j4acjec ,?is quoti5t add$ to ! diamet] ( ! small disk equals #a #j4cjjb #a4cjjb in*1 :i* is ! diamet] ( ! l>ge disk4 ,illu/ration3 ,fig4 #ae4 ,disk-&-,squ>e ,me?od ( ,accurately ,sett+ ,angul> ,"w ,! accompany+ table gives ! sizes ( ! l>g] disks to ! ne>e/ #j4jjja in* = :ole degrees rang+ f #e to #dj degrees inclusive4 ,incid5tally1 ! usefulness ( ^! disks c be increas$ by /amp+ on ea* "o its diamet] & also ! angle :i* x subt5ds :5 plac$ 9 contact ) ! /&>d #a-;in* disk4 ,,disk ,,diamet]s ,,= ,,angul> ,,measurem5t ---------------------------------------- ----- ,deg4 ,in* ,deg4 ,in* ,deg4 ,in* ---------------------------------------- ----- #e #a4jiab #ag #a4cdfh #bi #a4ffhj #f #a4aajd #ah #a4cgjh #cj #a4fihc #g #a4acjj #ai #a4ciec #ca #a4gbid #h #a4adii #bj #a4dbjc #cb #a4gfaj #i #a4agjb #ba #a4ddeg #cc #a4gicd #aj #a4aiji #bb #a4dgaf #cd #a4hbfb #aa #a4babj #bc #a4dihj #ce #a4hfjj #ab #a4bccd #bd #a4ebdi #cf #a4hidd #ac #a4beec #be #a4eebd #cg #a4ibie #ad #a4bgge #bf #a4ehje #ch #a4ifed #ae #a4cjjb #bg #a4fjij #ci #b4jjba #af #a4cbcd #bh #a4fchb #dj #b4jcif ---------------------------------------- ----- ,ma*9]y ---------------------------------------- ------------ ,disk-&-,squ>e ,me?od ( ,det]m9+ ,angles ,! me?od %[n 9 ,fig4 #ae = det]m9+ angles = sett+ up "w on a mill+ ma*9e or plan]1 possesses sev]al advantages4 ,no exp5sive tools are requir$1 ! me?od c be appli$ quickly1 & ! results obta9$ are q accurate en\gh = any b ! mo/ exact+ requirem5ts4 ,z w be se51 an ord9>y comb9ation squ>e is us$ 9 connection ) a disk1 ! head ( ! squ>e be+ set at diff]5t po9ts on ! blade accord+ to ! angle t is desir$4 ,!oretically1 a "o-in* disk c\ld be us$ = all angles f ab\t #f degrees up to a "r angle1 b 9 practice x is m conv5i5t & accurate to employ l>g] disks = ! l>g] angles4 ,! only inaccuracy result+ f ?is me?od is due to sett+ ! squ>e at ! ne>e/ 8scale fraction0 in/ead ( at ! exact po9t det]m9$ by calculation4 ,?is error is v small1 h[ev]1 & is negligible 9 practically all cases4 ,! dim5sion x requir$ = any desir$ angle a c be f\nd by multiply+ ! radius ( ! disk1 by ! cotang5t ( "o-half ! desir$ angle1 & add+ to ?is product ! radius ( ! disk4 ,example3 ,! squ>e blade is to be set to an angle ( #ae degrees #aj m9utes1 us+ a #b-;in* disk4 ,at :at di/ance x 7see ,fig4 #ae7 %\ld ! head ( ! squ>e be set8 ,cot #g degrees #ce m9utes #g4eaac1 & #g4eaac #a #a #h4eaac in*es4 ,by sett+ ! squ>e to #h in*es 8full10 ! blade w\ld be set v close to ! requir$ angle ( #ae degrees #aj m9utes4 ,locat+ ,"w by means ( ,size ,blocks ,! size-block me?od ( locat+ a jig-plate or o!r "p1 9 diff]5t positions on a la! faceplate1 = bor+ holes accurately at giv5 c5t]-to-c5t] di/ances1 is illu/rat$ 9 ,fig4 #af4 ,! way ! size blocks are us$ 9 ?is p>ticul> in/ance is z foll[s3 ,a pair ( accurate p>allels are atta*$ to a faceplate at "r angles to ea* o!r & !y are s locat$ t ! c5t] ( "o ( ! holes to be bor$ w co9cide ) ! la! sp9dle4 ,! hole :i* is align$ 9 ?is way %\ld be t "o on ! "w :i* is ne>e/ ! out] corn]1 s t ! rema9+ holes c be set 9 a c5tral position by adju/+ ! "w away f ! p>allels4 ,aft] ! fir/ hole is bor$1 ! "w is locat$ = bor+ ea* additional hole by plac+ size blocks ( ! requir$ wid? betwe5 ! edges ( ! "w & ! p>allels4 ,= in/ance1 to set ! plate = bor+ hole ,d1 size blocks 7or a comb9ation ( blocks or gages7 equal 9 wid? to dim5sion ,a w\ld be ins]t$ at ,a1 & o!r blocks equal 9 wid? to dim5sion ,b b5ea? ! "w z at ,b4 ,z w be se51 ! dim5sions ( ^! blocks equal ! horizontal & v]tical di/ances betwe5 holes ,c & ,d4 ,) ! use ( o!r comb9ations ( gage blocks1 any additional holes t might be requir$ are locat$ 9 ! c5tral position4 ,:ile only two holes are %[n 9 ?is case1 x w be und]/ood t ! plate c\ld be locat$ accurately = bor+ almo/ any numb] ( holes by ?is me?od4 ,illu/ration3 ,fig4 #af4 ,me?od ( sett+ ,"w on ,faceplate ) ,size ,blocks or ,gages ,incid5tally1 su* gages z ! ,johansson comb9ation gages are p>ticul>ly suit$ = "w ( ?is k9d1 z any dim5sion )9 ! m9imum & maximum limits ( a set c be obta9$ by simply plac+ ! requir$ sizes toge!r4 ,sometimes :5 su* gages are n available1 disks :i* h be5 gr\nd to ! requir$ diamet] are int]pos$ betwe5 ! p>allels & ! "w = secur+ accurate locations4 ,ano!r me?od ( secur+ a positive adju/m5t ( ! "w is to use p>allels compos$ ( two tap]+ sections1 :i* c be adju/$ to v>y ! wid? & be lock$ toge!r by means ( screws4 ,ea* half has ! same tap] s t out] edges are p>allel = any position1 & ! wid? is measur$ by us+ a micromet]4 ,! size-block me?od is usually appli$ to "w hav+ accurately ma*9$ edges1 al?\gh a "p hav+ edges :i* are ( a r\gh or irregul> %ape c be locat$ by ?is me?od1 if x is m\nt$ on an auxili>y plate hav+ accurately f9i%$ squ>e edges4 ,= in/ance1 if holes 7 to be bor$ 9 ! ca/+ = a jig templet :i* _h simply be5 plan$ on ! top & bottom1 ! ca/+ c\ld be bolt$ to a f9i%$ plate hav+ squ>e edges & ! latt] be set 9 ! diff]5t positions requir$1 by means ( size blocks4 ,comp>atively l>ge jig plates are sometimes locat$ = bor+ 9 ?is way & ! mill+ ma*9e is (t5 us$ in/ead ( a la!4 ,! ,ma/]-plate ,me?od ,:5 x is necess>y to ma*9e two or m plates s t !y are duplicates z to ! location ( holes1 circul> recesses1 etc41 :at is kn[n z a ma/]-plate is (t5 us$ = locat+ ! "w on ! la! faceplate4 ,?is ma/]-plate ,m 7see ,fig4 #ag7 conta9s holes :i* correspond to ^? want$ 9 ! "w1 & :i* accurately fit a c5tral plug ,p 9 ! la! sp9dle1 s t by engag+ fir/ "o hole & !n ano!r ) ! plug1 ! "w is accurately position$ = ! v>i\s op]ations4 ,:5 mak+ ! ma/]-plate1 great c>e %\ld be tak5 to h ! sides p>allel & ! holes at "r angles to ! sides1 z well z accurately locat$ ) ref]5ce to "o ano!r4 ,! v>i\s holes may be locat$ ) consid]able precision by ! use ( buttons z previ\sly describ$4 ,( c\rse1 x is necess>y to h a hole 9 ! ma/]-plate = ea* diff]5t position 9 :i* ! "w w h to be plac$ on ! faceplate2 = example1 if a circul> recess r 7 requir$1 a hole r exactly conc5tric ) x w\ld be ne$$ 9 ! ma/]-plate4 ,! me?od ( hold+ ! "w & locat+ x ) ref]5ce to ! holes 9 ! ma/]-plate w dep5d l>gely on its %ape4 ,! cyl9drical blank ,b illu/rat$1 is position$ by a recess 9 ! ma/]-plate 9 :i* x fits4 ,! "w is commonly held to ! ma/]-plate by means ( clamps & tap bolts or by screws :i* pass ?r\gh ! "w & into ! ma/]-plate4 ,sold] is sometimes us$ :5 x is n conv5i5t to hold ! "w by clamps or screws4 ,illu/ration3 ,fig4 #ag4 ,ma/]-plate appli$ to a ,b5* ,la! ,faceplate ,! plug ,p :i* locates ! ma/]-plate1 is fir/ turn$ to fit ! sp9dle or collet ( ! la! & ! out] or project+ end is r\ghturn$ = ! holes 9 ! ma/]-plate1 :i* %\ld all be f9i%$ to exactly ! same diamet]4 ,! plug is !n ins]t$ 9 ! sp9dle & gr\nd & lapp$ to a close fit = ! holes 9 ! ma/]-plate4 ,! latt]1 ) ! "w atta*$ to x1 is next clamp$ to ! faceplate by ! /raps %[n1 :i* engage a groove ar\nd ! edge ( ! ma/]-plate4 ,! fir/ hole is f9i%$ by drill+ to )91 say1 #j4jje or #j4jjf in* ( ! size1 & !n bor+ practically to size1 a v small am\nt be+ left = ream+ or gr9d+4 ,! rema9+ holes c !n be f9i%$ 9 ! same way1 ! "w be+ positively locat$ 9 ea* case by loos5+ ! ma/]-plate & engag+ ! prop] hole 9 x ) ! c5tral plug4 ,x is app>5t t by ! use ( ?is same ma/]-plate1 a numb] ( pieces ,b c\ld be made :i* w\ld be practically duplicates4 ,! ma/]-plate me?od ( locat+ "w c be appli$ 9 _m diff]5t ways4 ,x is us$ = mak+ duplicate dies1 = accurately locat+ ! v>i\s holes 9 wat* movem5ts1 & = _m o!r op]ations requir+ great precision4 ,ma/]-plates are q frequ5tly us$ by toolmak]s :5 x is necess>y to produce a numb] ( drill jigs :i* are to be us$ = drill+ holes 9 diff]5t p>ts hav+ ! same relative locations1 ?us requir+ jigs t are duplicates )9 v close limits4 ,:5 a ma/]-plate is requir$1 t is to be us$ 9 mak+ duplicates ( an exi/+ model1 ! holes are bor$ 9 ! ma/]-plate by rev]s+ ! process illu/rat$ 9 ,fig4 #ag4 ,t is1 ! c5tral plug ,p is turn$ to fit ! l>ge/ hole 9 ! model & ! latt] ) ! atta*$ ma/]-plate blank is clamp$ to la! faceplate4 ,! fir/ hole is !n bor$ to )9 say #j4jjb in* ( ! f9i% diamet]1 to all[ = gr9d+1 provid$ ! ma/]-plate is to be h>d5$4 ,! c5tral plug is !n turn$ d[n to fit ! next l>ge/ hole & ! second hole is bor$ 9 ! ma/]-plate4 ,?is me?od is cont9u$ until all ! holes are bor$4 ,9 ord] to prev5t any *ange 9 ! position ( ! ma/]-plate relative to ! model1 x may be secur$ by ins]t+ d[el-p9s ?r\gh bo? p>ts1 ! "w be+ held to ! la! faceplate by ord9>y screw clamps4 ,if ! holes 9 ! model d n ext5d cle> ?r\gh1 a flat plate hav+ p>allel sides may be int]pos$ betwe5 ! model & ma/]-plate to provide cle>ance betwe5 ! two & prev5t cutt+ into ! model :5 bor+ ! ma/]-plate4 ,,*apt] ,,ii ,,accurate ,,divid+ ,,& ,,spac+ ,,me?ods ,toolmak]s & ma*9i/s occasionally f9d x necess>y to locate a numb] ( equally-spac$ holes on a /raight l9e betwe5 two po9ts1 or to divide a circle ) holes :i* are equi-di/ant )9 a v small limit ( accuracy4 ,sev]al divid+ & spac+ me?ods are describ$ 9 ?is *apt]2 "s ( ^! me?ods c1 ) slight modification1 be appli$ 9 v>i\s ways4 ,illu/ration3 ,fig4 #ah4 ,me?od ( ,drill+ ,small ,equally-spac$ ,holes 9 ,r[s ,locat+ ,small ,equally-spac$ ,holes 9 ,r[s ,x is sometimes necess>y to drill "o or m r[s ( small equally-spac$ holes4 ,! be/ me?od ( do+ ?is "w naturally dep5ds1 to "s ext5t1 ^u ! accuracy requir$1 b ev5 :5 a high degree ( accuracy is n necess>y1 if an attempt is made to lay out ! holes & drill !m 9 ! ord9>y way1 consid]able "t is usually requir$ & ! results are liable to be unsatisfactory4 ,= example1 suppose a r[ ( holes _/ in* 9 diamet] & in* c5t]-to-c5t] di/ance 7 to be drill$ 9 a flat plate4 ,"s ma*9i/s w\ld proce$ by fir/ scrib+ a c5t]-l9e & !n lay+ out ! c5t]s ( ! holes by means ( divid]s4 ,a mu* easi] & accurate me?od is illu/rat$ 9 ,fig4 #ah1 & is z foll[s3 ,lay out ! fir/ hole & drill x2 !n secure a small piece ( flat /eel = a drill guide1 drill a hole ?r\gh x1 bevel "o corn] & scribe a f9e l9e on ! bevel$ section1 z %[n 9 ! illu/ration4 ,align ! hole drill$ 9 ! guide ) ! hole 9 ! "w1 by ins]t+ a close-fitt+ plug1 & clamp a scale aga9/ "o edge ( ! drill guide s t "o ( ! graduation m>ks exactly mat*es ) ! l9e on ! guide4 ,! edge ( ! scale mu/ also be locat$ p>allel to ! c5t]-l9e ( ! r[ ( holes to be drill$4 ,n[ proce$ to drill ! holes1 sett+ ! drill guide ea* "t1 to :atev] graduation l9e repres5ts ! requir$ spac+ or pit* ( ! holes4 ,x is advisable to use a magnify+ glass to accurately align ! graduation m>k on ! scale ) ! l9e on ! drill guide4 ,if two or m r[s ( holes are to be drill$ p>allel1 ! guide block c be drill$ accord+ly1 s t ! diff]5t r[s ( holes c be f9i%$ at ! same "t4 ,! drill guide block %\ld be reliev$ slightly 9 ! c5t] s z to insure ! ends ( ! block be>+ aga9/ ! edge ( ! scale4 ,a toolmak] or ma*9i/ c drill a r[ ( holes accurately by ?is simple me?od1 9 ! "t requir$ to lay !m out 9 ! usual way1 & ev5 ?\gh accuracy is n necess>y1 x is quick] to drill holes by ?is me?od ?an by ! "o m commonly employ$4 ,use ( ,disks = ,locat+ ,equally-,spac$ ,holes ,a simple me?od ( spac+ holes t are to be drill$ 9 a /raight l9e is illu/rat$ 9 ,fig4 #ai4 ,two disks are made1 ea* hav+ a diamet] equal to ! c5t]-to-c5t] di/ance requir$ betwe5 ! holes4 ,^! disks mu/ also h holes :i* are exactly c5tral ) ! outside to act z a guide = ! drill or ream]4 ,! fir/ two holes are drill$ 9 ! "w :ile ! disks are clamp$ s t !y are 9 contact ) ea* o!r & also ) ! /raight$ge z %[n4 ,"o disk is !n plac$ on ! opposite side ( ! o!r1 z indicat$ by ! dott$ l9e1 & a ?ird hole is drill$2 ?is process ( sett+ "o disk aga9/ ! opposite side ( ! o!r is cont9u$ until all ! holes are drill$4 ,:5 x is necess>y to drill a p>allel r[ ( 8/agg]$0 holes1 ! second r[ c be locat$ by plac+ disks ( ! prop] size 9 contact ) ! fir/ r[ ( disks4 ,illu/ration3 ,fig4 #ai4 ,locat+ ,equi-di/ant ,holes 9 a ,/raight ,l9e by ,means ( ,disks & ,/raight$ge ,a me?od ( us+ disks1 :i* is pref]able = v accurate "w1 is %[n 9 ,fig4 #bj4 ,! disks are clamp$ aga9/ ea* o!r & along /raight$ge ,a by ! screws %[n1 & if ! outside diamet]s are correct & ! guide holes conc5tric ) ! outside1 v accurate "w c be done4 ,) ?is device !re may be z _m disks z !re are holes to be drill$1 if ! numb] ( holes is comp>atively small1 b if x is necess>y to drill a long r[ ( holes1 ! disks & frame are %ift$ along an auxili>y /raight$ge ,b1 ! hole 9 "o ( ! end disks be+ align$ ) ! la/ hole drill$ by ins]t+ a close-fitt+ plug ?r\gh ! disk & hole4 ,adju/able ,jig = ,accurate ,hole ,spac+ ,an adju/able jig = accurately spac+ small holes is %[n 9 ,fig4 #ba4 ,illu/ration3 ,fig4 #bj4 ,special ,disk-jig = ,precision ,drill+ ,?is =m is especially adapt$ = locat+ a numb] ( equally spac$ holes betwe5 two previ\sly drill$ or bor$ holes1 & ! accuracy ( ! me?od lies 9 ! fact t a slight error 9 ! orig9al spac+ ( ! guide bu%+ is multipli$1 &1 !re=e1 easily detect$4 ,!re are two ( ^! guide bu%+s ,a & ,b :i* are c>ri$ by indep5d5t slides4 ,^! slides c be %ift$ along a dovetail groove aft] loos5+ ! screws ( clamp-gib ,c4 ,to illu/rate ! me?od ( us+ ?is jig1 suppose five equally spac$ holes are to be locat$ betwe5 two holes t are #ab in*es ap>t4 ,z ! c5t]-to-c5t] di/ance betwe5 adjac5t holes is #b in*es1 slides ,a & ,b w\ld be set s t ! dim5sion x equals #b in*es plus ! radii ( ! bu%+s4 ,a /raight$ge is !n clamp$ to ! "w 9 su* position t a close-fitt+ plug c be ins]t$ ?r\gh ! end holes :i* 7 previ\sly drill$ or bor$4 ,!n ) a plug ins]t$ ?r\gh1 say1 bu%+ ,b & "o ( ! end holes1 ! fir/ hole is drill$ & ream$ ?r\gh bu%+ ,a2 ! jig is !n %ift$ to ! left until ! plug 9 ,b ent]s ! hole j made4 ,! second hole is !n drill$ & ream$ ?r\gh bu%+ ,a & ?is drill+ & %ift+ ( ! jig is cont9u$ until ! la/ hole is f9i%$4 ,! di/ance betwe5 ! la/ hole & ! orig9al end hole at ! left is next te/$ by attempt+ to ins]t close-fitt+ plugs ?r\gh bo? bu%+s4 ,evid5tly1 if !re 7 any inaccuracy 9 ! spac+ ( ! bu%+s1 ?is w\ld be multipli$ z _m times z ! jig 0 %ift$1 ! error be+ accumulative4 ,to illu/rate h[ ! error accumulates1 suppose t ! bu%+s 7 #j4jja in* too f> ap>t2 !n ! di/ance to ! fir/ hole w\ld be #b4jja in*1 to ! second hole1 #d4jjb in*1 & f9ally ! di/ance f ! fir/ to ! six? hole w\ld be #aj4jje in*es2 consequ5tly1 ! di/ance betwe5 ! six? & sev5? holes w\ld equal #ab-aj4jje #a4iie in*1 or #j4jje in* less ?an ! requir$ spac+1 assum+1 = ! sake ( illu/ration1 t ! fir/ & la/ holes 7 exactly #ab in*es ap>t4 ,9 case ( an error ( #j4jje in*1 ! bu%+s w\ld be set clos] toge!r an am\nt equal to "o-fif? ( ?is error1 z ne> z c\ld be det]m9$ ) a micromet]1 & all ( ! holes w\ld !n be re-ream$4 ,illu/ration3 ,fig4 #ba4 ,adju/able ,jig = ,accurate ,hole ,spac+ ,me?ods ( ,accurately ,divid+ a ,circle ,sometimes x is necess>y to ma*9e a numb] ( holes 9 a plate s t all ! holes are on a circle or equi-di/ant f a c5tral po9t1 & also ! same di/ance ap>t1 )9 v small limits4 ,a simple me?od ( spac+ holes equally is illu/rat$ at ,a1 ,fig4 #bb4 ,a numb] ( buttons equal to ! numb] ( holes requir$ are gr\nd & lapp$ to exactly ! same diamet]1 pref]ably by m\nt+ !m all on an arbor & f9i%+ !m at ! same "t4 ,! ends %\ld also be made squ>e ) ! cyl9drical surface ( ! button4 ,:5 ^! buttons are f9i%$1 ! diamet] is c>efully measur$ & ?is dim5sion is subtract$ f ! diamet] ( ! circle on :i* ! holes are to be locat$1 9 ord] to obta9 ! diamet] d 7see illu/ration74 ,a n>r[ %\ld] is !n turn$ on ! plate to be bor$1 ! diamet] be+ made exactly equal to dim5sion d4 ,by plac+ ! buttons 9 contact ) ?is %\ld]1 !y are accurately locat$ radially & c !n be set equi-di/ant f ea* o!r by ! use ( a micromet]4 ,9 ?is p>ticul> case1 x w\ld be advisable to beg9 by sett+ ! f\r buttons :i* are #ij degrees ap>t & !n ! rema9+ f\r4 ,! buttons are next us$ = sett+ ! "w prep>atory to bor+4 7,see 8,button ,me?od ( ,accurately ,locat+ ,"w407 ,illu/ration3 ,fig4 #bb4 ,f\r ,me?ods ( ,accurately ,divid+ a ,circle ,correct+ ,spac+ ,errors by ,split ,r+ ,me?od ,ano!r me?od ( secur+ equal spac+ = holes 9 index+ :eels1 etc41 is illu/rat$ at ,b1 ,fig4 #bb4 ,?is me?od1 h[ev]1 is n to be recomm5d$ if ! diamet] ( ! circle on :i* ! holes are to be locat$1 mu/ be v accurate4 ,! disk or r+ 9 :i* ! holes are requir$1 is =m$ ( two sections e & f1 in/ead ( be+ "o solid piece4 ,! c5t]s = ! holes are fir/ laid out z accurately z possible on r+ e4 ,p>ts e & f are !n clamp$ toge!r & ! holes are drill$ ?r\gh ^! two sections4 ,obvi\sly1 :5 ! holes are laid out & drill$ 9 ?is way1 !re w be "s error 9 ! spac+1 &1 consequ5tly1 all ( ! holes w\ld n mat*1 except :5 plate e is 9 ! position x occupi$ :5 be+ drill$4 ,:atev] errors may exi/ 9 ! spac+ c be elim9at$1 h[ev]1 by successively %ift+ plate e to diff]5t positions & re-ream+ ! holes = ea* position4 ,a tap] ream] is us$ & two p9s %\ld be provid$ hav+ ! same tap] z ! ream]4 ,r+ e is fir/ locat$ s t a hole is align$ q accurately ) "o 9 ! l[] plate4 ,! r+ is !n clamp$ & ! hole is p>tly ream$1 ! ream] be+ ins]t$ f> en\gh to f9i% ! hole 9 plate e & also cut cle> ar\nd 9 ! upp] "p ( plate f4 ,"o ( ! tap] p9s is !n driv5 into ?is hole & !n a hole on ! opposite side is p>tly ream$1 aft] :i* ! o!r p9 is ins]t$4 ,! rema9+ holes are n[ ream$ 9 ! same way1 & ! ream] %\ld be f$ 9 to ! same dep? 9 ea* case4 ,if a pair ( holes is consid]ably out ( alignm5t1 x may be necess>y to run ! ream] 9 to a great] dep? ?an 0 requir$ = ! fir/ pair ream$1 & 9 su* a case all ! holes %\ld be re-ream$ to secure a uni=m size4 ,! next /ep 9 ?is op]ation is to remove ! tap] p9s & clamps or turn index plate e "o hole & aga9 clamp x 9 position4 ,! ream+ process j describ$ is !n repeat$2 ! holes on opposite sides ( ! plate are re-ream$ some:at deep]1 ! tap] p9s are ins]t$1 & !n all ( ! rema9+ holes are re-ream$ to secure p]fect alignm5t = ! new position ( ! plate4 ,by repeat+ ?is process ( %ift+ plate e & re-ream+ ! holes1 :atev] error t may h exi/$ orig9ally 9 ! spac+ ( ! holes1 w practically be elim9at$4 ,x w\ld be v difficult1 h[ev]1 to h ^! holes locat$ ) any great degree ( accuracy1 on a circle ( giv5 diamet]4 ,circul> ,spac+ by ,contact ( ,uni=m ,disks ,:5 an accurate index+ or divid+ :eel is requir$ on a ma*9e1 ! me?od ( secur+ accurate divisions ( ! circle illu/rat$ at ,c1 ,fig4 #bb1 is sometimes employ$4 ,!re is a s]ies ( circul> disks or bu%+s equal 9 numb] to ! divisions requir$1 & ^! disks are all 9 contact ) ea* o!r & ) a circul> boss or %\ld] on ! plate to :i* !y are atta*$4 ,! space betwe5 adjac5t disks is us$ to accurately locate ! divid+ :eel1 engagem5t be+ made ) a suitable lat* or index+ device4 ,:5 mak+ a divid+ :eel ( ?is k9d1 all ( ! disks are gr\nd & lapp$ to ! same diamet] & !n ! diamet] ( ! c5tral boss or plate is gradually r$uc$ until all ( ! disks are 9 contact ) ea* o!r & ) ! boss4 ,= an example ( ! practical application ( ?is me?od see 8,orig9at+ a ,precision ,divid+ ,:eel40 ,spac+ by ,correct+ ! ,accumulat$ ,error ,ano!r index+ me?od ( spac+ holes equi-di/ant1 is illu/rat$ by ! diagram at ,d1 ,fig4 #bb4 ,an accurately fitt+ plug is ins]t$ 9 ! c5tral hole ( ! plate 9 :i* holes are requir$4 ,two arms h are closely fitt$ to ?is plug b are free to rotate & are provid$ ) a f9e-pit* screw & nut at ! out] ends = adju/+ ! di/ance betwe5 ! arms4 ,ea* arm conta9s an accurately made1 h>d5$ /eel bu%+ k locat$ at ! same radial di/ance f ! c5t] ( ! plate4 ,^! bu%+s are us$ z a guide = ! drill & ream] :5 ma*9+ ! holes 9 ! plate4 ,to det]m9e ! c5t]-to-c5t] di/ance betwe5 ! bu%+s1 divide #cfj by twice ! numb] ( holes requir$2 f9d ! s9e correspond+ to ! angle ?us obta9$1 & multiply x by ! diamet] ( ! circle ^u :i* ! holes are locat$4 ,= example1 if !re 7 to be elev5 holes on a circle #h in*es 9 diamet]1 ! di/ance betwe5 ! c5t]s ( ! bu%+s w\ld equal #cfj -------------- #af4cf degrees4 #b #aa ,! s9e ( #af4cf degrees is #j4bhae1 & #j4bhae #h #b4beb in*es4 ,! arms are adju/$ to locate ! c5t]s ( ! bu%+s ?is di/ance ap>t1 by plac+ closely fitt+ plugs 9 ! bu%+s & measur+ f "o plug to ano!r ) a micromet] or v]ni] calip]4 ,( c\rse1 :5 tak+ ?is measurem5t1 all[ance is made = ! diamet] ( ! plugs4 ,aft] ! arms are set1 a hole is drill$ & ream$2 an accurately fitt+ plug is !n ins]t$ ?r\gh ! bu%+ & hole to secure ! arms :5 drill+ & ream+ ! adjac5t hole4 ,! radial arms are !n index$ "o hole s t ! plug c be ins]t$ ?r\gh "o ( ! arms & ! la/ hole ream$4 ,! ?ird hole is !n drill$ & ream$1 & ?is op]ation is repeat$ = all ( ! holes4 ,evid5tly1 if ! c5t]-to-c5t] di/ance betwe5 ! bu%+s is n exactly "r1 ! error w be indicat$ by ! position ( ! arms relative to ! la/ hole & ! fir/ "o ream$2 moreov]1 ?is error w be multipli$ z _m times z !re are holes4 ,= in/ance1 if ! arms 7 too f> ap>t1 ! diff]5ce betwe5 ! c5t]-to-c5t] di/ance ( ! la/ pair ( holes & ! c5t]-to-c5t] di/ance ( ! bu%+s 9 ! arms1 w\ld equal1 9 ?is p>ticul> case1 eight times ! error1 & ! arms %\ld be re-adju/$ accord+ly4 ,l>g] bu%+s w\ld !n be ins]t$ 9 ! arms & ! holes re-ream$1 ?is op]ation be+ repeat$ until ! holes 7 all equi-di/ant4 ,z w be se51 ! value ( ?is me?od lies 9 ! fact t x %[s ! accumulat$ error4 ,?us1 if ! arms 7 #j4jjje in* too f> ap>t1 ! diff]5ce betwe5 ! fir/ & la/ hole w\ld equal #h #j4jjje #j4jjd in*4 ,?is same pr9ciple ( divid+ c be appli$ 9 v>i\s ways4 ,= in/ance1 ! radial arms if slightly modifi$1 c\ld be us$ = drill+ equally-spac$ holes 9 ! p]iph]y or disk ( a plate1 or1 if a suitable m>k+ device 7 atta*$1 a device ( ?is k9d c\ld be us$ = accurately divid+ circul> p>ts4 ,orig9at+ a ,precision ,divid+ ,:eel ,!re are v>i\s me?ods employ$ = mak+ accurate index+ :eels = a def9ite numb] ( divisions4 ,"o ( ^! me?ods1 suitable p>ticul>ly = small numb]s ( divisions1 employs a split :eel ) a s]ies ( tap] holes ream$ ?r\gh ! two divisions4 ,by %ift+ ! two divisions f po9t to po9t 7z expla9$ 9 connection ) sket* ,b1 ,fig4 #bb7 & ream+ & re-ream+ ! tap] holes at ea* %ift+1 !y may f9ally be br\ght v accurately into position4 ,ano!r me?od t has be5 employ$ consi/s 9 clamp+ ab\t ! rim ( ! divid+ :eel a numb] ( precisely simil> blocks1 fitt+ close to ea* o!r & to ! :eel itself4 ,^! blocks are !n us$ = locat+ ! :eel 9 ea* ( its sev]al positions 9 actual "w4 ,a ?ird & simpl] me?od 7a modification ( ! "o la/ describ$7 consi/s 9 gr9d+ a s]ies ( disks & clamp+ !m ar\nd a rim ( su* diamet] t ! disks all t\* ea* o!r & ! rim simultane\sly1 z expla9$ 9 connection ) sket* ,c1 ,fig4 #bb4 ,! :eel describ$ 9 ! foll[+1 :i* is illu/rat$ 9 ,fig4 #bc1 0 made 9 ?is way4 ,illu/ration3 ,fig4 #bc4 ,precision ,divid+ ,:eel ,disks ,a are clamp$ aga9/ an accurately gr\nd face ( ! :eel ,b & are suppos$ to j t\* ea* o!r all ar\nd1 & to be ea* ( !m 9 contact ) ! gr\nd cyl9drical surface at x4 ,!y are held 9 prop] position by bolts ,c & nuts ,d4 ,! bolts fit loosely 9 ! holes ( ! disks or bu%+s ,a s t ! latt] are free to be locat$ z may be desir$ ) ref]5ce to ! bolts4 ,"o or two improvem5ts 9 ! con/ruction ( ?is type ( divid+ :eel may be not$ be=e proce$+ to a description ( ! way 9 :i* x is made4 ,= "o ?+1 in/ead ( hav+ an index+ bolt ent] ! ,v-space betwe5 two adjo9+ disks1 a small] diamet] y is gr\nd on ea* ( !m1 ov] :i* lock+ f+] or pawl passes1 hold+ ! :eel firmly f movem5t 9 ei!r direction4 ,?is con/ruction has ! advantage ( a probable less5+ ( error by locat+ on ea* bu%+ in/ead ( betwe5 two bu%+s2 moreov]1 x gives a bett] hold+ surface & bett] hold+ angles ?an w\ld be ! case if ?is small] diamet] 7 n provid$4 ,a second improvem5t lies 9 ! me?od ( clamp+ ! bu%+s ,a 9 place4 ,in/ead ( provid+ ea* bolt ) a sep>ate wa%]1 a r+ ,f is us$4 ,?is r+ fits closely on a seat turn$ to receive x on ! divid+ :eel ,b4 ,:5 "o bu%+ ,a has be5 clamp$ 9 place1 ! disk is lock$ f movem5t s t !re is no possibility1 9 clamp+ ! rema9+ bu%+s1 ( hav+ _! location di/urb$ 9 ! slighte/ degree by ! turn+ ( ! nuts 9 fa/5+ !m 9 place4 ,! bu%+s ,a1 ( :i* !re 7 9 ?is case #bd1 7 all gr\nd exactly to ! requir$ diamet]s on _! locat+ & lock+ surfaces4 ,! important ?+s 9 ?is op]ation are1 fir/1 t ! l>ge or locat+ diamet] ( ! bu%+ %\ld be exactly to size2 & second1 t ?is surface %\ld be 9 exact alignm5t ) ! diamet] 9 :i* ! lock+ is done2 &1 f9ally1 t ! face ( ! bu%+ %\ld be squ>$ ) ! cyl9drical surfaces4 ,a ref9$ exactness = ! diamet] ( ! lock+ surfaces is n s important1 z ! =m ( lock+ device provid$ all[s slight v>iations at ?is po9t )\t impairm5t ( accuracy4 ,?is dim5sion 0 kept )9 v close limits1 h[ev]4 ,! tru? ( ! two cyl9drical surfaces & ! face ( ! bu%+ 0 assur$ by f9i%+ all ^! surfaces 9 "o op]ation on ! gr9d+ ma*9e4 ,! siz+ ( ! out] diamet] ( ! bu%+1 :i* 0 #a4aeh in*1 mu/ be done s accurately t x 0 n ?\ght wise to tru/ to ! ord9>y micromet] calip]4 ,an index+ device 0 !re=e made hav+ a calip]+ lev] ) a long end1 9 ! ratio ( #aj to #a1 :i* actuat$ ! plung] ( a dial te/ indicator ( ! well-kn[n type made by ! ,wal?am ,wat* ,tool ,co4 ,! ?\s&? graduations on ! dial ( ?is indicator w\ld !n read 9 t5-?\s&?s1 p]mitt+ read+s to be tak5 to "o-half or "o-qu>t] ( ?is am\nt4 ,! f9al measurem5ts ) ?is device 7 all tak5 aft] dipp+ ! bu%+s 9 wat] ( a c]ta9 temp]ature1 long en\gh to give assurance t ?is temp]ature 0 univ]sal 9 all ! p>ts measur$4 ,x w be und]/ood1 ( c\rse1 9 ?is connection1 t gett+ ! diamet] ( ^! bu%+s absolutely to #a4aeh in* 0 n s important z gett+ !m all exactly alike1 :e!r slightly ov] or slightly "u ?is dim5sion2 h5ce1 ! precaution tak5 9 measurem5t4 ,:eel ,b 0 next gr\nd d[n ne>ly to size1 great c>e be+ tak5 t x %\ld run exactly conc5tric ) ! axis4 ,z soon z ! diamet] ( ! surface x 0 br\ght ne>ly to ! requir$ dim5sion z obta9$ by calculation1 ! disks 7 tri$ 9 place4 ,! fir/ "o 0 put 9 position ) its loose hole c5tral on ! bolt & clamp$ 9 place "u r+ ,f4 ,! next bu%+ 0 !n press$ up aga9/ x & aga9/ ! surface x ( ! :eel & clamp$ 9 place4 ,! ?ird "o 0 simil>ly clamp$ 9 contact ) its neighbor+ bu%+ & ! :eel1 & s on1 until ! :ole circle 0 complet$4 ,x 0 !n f\nd t ! la/ disk w\ld n fill ! rema9+ space4 ,?is requir$ ! gr9d+ (f ( "s /ock f surface x1 & a repetition ( ! fitt+ ( ! bu%+s ,a until !y exactly fill$ ! space provid$ = !m4 ,illu/ration3 ,fig4 #bd4 ,precision ,divid+ ,:eel & its ,index+ ,me*anism ,?is op]ation requir$1 ( c\rse1 consid]ably m skill ?an a simple description ( ! job w\ld indicate4 ,"o ( ! po9ts t _h to be c>efully look$ out = 0 ! clean+ ( all ! surfaces 9 contact4 ,a bit ( du/ or l9t on "o ( ! surfaces w\ld ?r[ ! fitt+ entirely out4 ,! temp]ature ( ! p>ts 0 ano!r important consid]ation4 ,z an evid5ce ( ! accuracy ) :i* ! "w 0 done1 x might be m5tion$ t x 0 f\nd impossible to d ?is fitt+ on a b5* on ! s\!rn or sunny side ( ! %op1 ! v>iations ( temp]ature betwe5 morn+ & noon1 & betwe5 bright sun%9e & pass+ cl\ds1 be+ su* t ! disks w\ld n fit uni=mly4 ,! v>iation f ^! m9ute temp]ature *anges result$ f ! diff]5t coeffici5ts ( expansion ( ! iron :eel & ! /eel bu%+s4 ,! obvi\s ?+ to d w\ld be to build a room = ?is "w kept at a con/ant temp]ature & pref]ably t ( ! body1 s t ! heat ( ! body w\ld make no diff]5ce 9 ! results4 ,x 0 f\nd suffici5t 9 ?is case1 h[ev]1 to d ! "w on ! nor!rn side ( ! %op :]e ! temp]ature 0 m ne>ly con/ant1 n be+ affect$ by v>iations 9 sun%9e4 ,! divid+ :eel1 ! con/ruction ( :i* has j be5 describ$1 0 made by ! ,fell[s ,ge> ,%ap] ,co4 ,x is us$ = index+ ! ,fell[s ge> cutt]s 9 ! ma*9e 9 :i* ! tee? are gr\nd4 ,! index+ me*anism ( ?is ma*9e is %[n 9 ,fig4 #bd4 ,x is op]at$ by a h&le or lev] p9n$ to rock-%aft ,h1 to :i* is key$ arm ,j4 ,pivot$ to ,j is a pawl ,k engag+ ! tee? ( rat*et ,l1 :i* revolves loosely on %aft ,h4 ,?is rat*et ,l controls ! movem5t ( lock+ f+] ,e4 ,! p>ts are %[n 9 _! normal or lock$ position 9 ! engrav+4 ,z ! h&le on %aft ,h is pull$ 9 ! direction indicat$ by ! arr[1 arm ,j is rais$1 c>ry+ ! rat*et :eel ar\nd to ! "r4 ,?is all[s flat spr+ ,m to drop (f ( ! rat*et too?1 p]mitt+ helical spr+ ,o to raise lat* ,e & ?us leave ! :eel free4 ,! cont9u$ movem5t ( ! h&-lev] & ( rock-%aft ,h1 by means ( ge> ,n1 int]m$iate p9ion ,p & ge> ,q1 causes ! index+ pawl ,r1 :i* is pivot$ to ge> ,q & acts on ! head ( "o ( ! bolts ,c 7see ,fig4 #bc71 to index ! :eel "o /ep4 ,j be=e rea*+ its new location ! new too? ( rat*et :eel ,l com+ up1 be>s d[n on ! top ( spr+ ,m1 press+ lat* ,e into place aga9/ ! t5sion ( coil spr+ ,o4 ,by ?is means ! :eel is lock$ 9 position4 ,:5 ! op]ator pu%es ! h&le on %aft ,h back aga9 to its position ( re/1 ! pawl ,r is retract$ into position to act on ! next bolt head = ! next index+4 ,/>-:eel ,l rema9s /ation>y on ?is backw>d movem5t1 be+ prev5t$ f revolv+ by ! not* on ! top ( ! too? into :i* spr+ ,m fits4 ,pawl ,k on its return engages ) ! next too? ( ?is :eel1 ready = ! next index+ op]ation4 ,a slight rot>y adju/m5t ( divid+ :eel ,b1 indep5d5t ( ?is index+ me*anism1 is requir$ = ! fe$+ ( ! ma*9e4 ,?is is accompli%$ by ! end movem5t ( lat* ,e1 :i* is pivot$ 9 slide ,s4 ,?is slide is press$ to ! "r by spr+ plung] ,t1 & is adju/$ positively 9 ! o!r direction by fe$-screw ,u1 :i* is f9ely graduat$ to p]mit accurate adju/m5t4 ,! accuracy 9 index+ obta9$ by ! use ( a :eel ?us made 0 requir$ to br+ ! f9i%$ cutt]s )9 ! v n>r[ limits all[$ = !m 9 ! f9al inspection4 ,,*apt] ,,iii ,,locat+ ,,"w ,,= ,,bor+ ,,on ,,mill+ ,,ma*9e ,x is (t5 desirable to p]=m bor+ op]ations on ! mill+ ma*9e1 p>ticul>ly 9 connection ) jig "w4 ,l>ge jigs1 :i* because ( _! size or %ape c\ld n be conv5i5tly h&l$ 9 ! la!1 & also a v>iety ( small] "w1 c (t5 be bor$ to advantage on ! mill+ ma*9e4 ,:5 su* a ma*9e is 9 good condition1 ! necess>y adju/m5ts ( ! "w 9 bo? v]tical & horizontal planes1 c be made ) consid]able accuracy by ! direct use ( ! graduat$ fe$-screw dials4 ,x is good practice1 h[ev]1 :5 mak+ adju/m5ts 9 ?is way1 to *eck ! accuracy ( ! sett+ by measur+ ! c5t] di/ances betwe5 ! holes directly4 ,= ! purpose ( obta9+ f9e adju/m5ts :5 bor+ on ! mill+ ma*9e1 ! ,br[n amp2 ,%>pe ,mfg4 ,co4 makes special scales & v]ni]s t are atta*$ to mill+ ma*9es1 s t ! table may be set by direct measurem5t4 ,by atta*+ a scale & v]ni] to ! table & saddle1 respectively1 & a second scale to ! column ) a v]ni] on ! knee1 bo? longitud9al & v]tical measurem5ts c be made quickly & accurately1 & ! *ance ( error result+ f inaccuracy ( ! screw1 or f lo/ motion betwe5 ! screw & nut1 is elim9at$4 ,*eck+ ,location ( ,holes by ,micromet]-&-plug ,me?od ,"o me?od ( *eck+ ! accuracy ( ! location ( holes bor$ 9 ! mill+ ma*9e1 is to ins]t closely fitt+ gr\nd plugs into ! bor$ holes & !n det]m9e ! c5t]-to-c5t] di/ance by tak+ a direct measurem5t across ! plugs ) a micromet] or v]ni] calip]4 ,= example1 if holes 7 to be bor$ 9 a jig-plate1 z %[n 9 ,fig4 #a1 assum+ t hole ,a 7 f9i%$ fir/1 ! plat5 w\ld !n be mov$ two in*es1 z %[n by ! fe$ dial2 hole ,b w\ld !n be bor$ slightly "u size4 ,plugs %\ld !n be accurately fitt$ to ^! holes1 hav+ project+ ends1 pref]ably ( ! same size4 ,by measur+ f "o ( ^! plugs to ! o!r ) a v]ni] or micromet] calip]1 ! c5t] di/ance betwe5 !m c be accurately det]m9$1 all[ance be+ made1 ( c\rse1 = ! radii ( ea* plug4 ,if ?is di/ance is incorrect1 ! "w c be adju/$ be=e f9i%+ ,b to size1 by us+ ! fe$-screw dial4 ,aft] hole ,b is f9i%$1 ! knee c\ld be dropp$ #a4e in*1 z %[n by ! v]tical fe$ dial1 & hole ,c bor$ slightly "u size2 !n by ! use ( plugs1 z be=e1 ! location ( ?is hole c\ld be te/$ by measur+ c5t] di/ances betwe5 ,c-,b & ,c-,a4 ,an example ( "w requir+ ! micromet]-&-plug te/1 is %[n set up 9 ! mill+ ma*9e 9 ,fig4 #be4 ,! l>ge circul> plate %[n has a c5tral hole & x 0 necess>y to bore ! out] holes 9 correct relation ) ! c5t] hole )9 a limit ( #j4jjje in*4 ,! c5t] hole 0 fir/ bor$ & ream$ to size2 !n an accurately fitt+ plug 0 ins]t$ & ! di/ances to all ! o!r holes 7 *eck$ by measur+ f ?is plug4 ,?is me?od ( te/+ ) ! plugs is int5d$ to prev5t errors :i* might occur because ( we> 9 ! fe$-screws or nuts1 t w\ld cause ! graduat$ dials to give an incorrect read+4 ,on "s jig "w1 suffici5t accuracy c\ld be obta9$ by us+ ! fe$-screw dials alone1 t is1 )\t te/+ ) ! plugs1 9 :i* case ! accuracy w\ld naturally dep5d l>gely on ! condition ( ! ma*9e4 ,illu/ration3 ,fig4 #be4 ,example ( ,precision ,bor+ on ,mill+ ,ma*9e ,a me?od t is a modification ( ! "o 9 :i* plugs are us$ to te/ ! c5t] di/ance is z foll[s3 ,all ! holes are fir/ drill$ ) suitable all[ance = bor+1 ! location be+ obta9$ directly by ! fe$-screw dials4 ,a special bor+-tool1 ! end ( :i* is gr\nd true ) ! %ank1 is !n ins]t$ 9 ! sp9dle & ! fir/ hole1 z at ,a 9 ,fig4 #a is f9i%$1 aft] :i* ! plat5 is adju/$ = hole ,b by us+ ! dial z be=e4 ,a close-fitt+ plug is !n ins]t$ 9 hole ,a & ! accuracy ( ! sett+ is obta9$ by measur+ ! di/ance betwe5 ?is plug & ! end ( ! bor+-tool1 :i* is a comb9ation tool & te/ plug4 ,9 a simil> mann]1 ! tool is mov$ f "o position to ano!r1 &1 z all ! holes h be5 previ\sly drill$1 all are bor$ )\t remov+ ! tool f ! sp9dle4 ,ano!r modification ( ! micromet]-&-plug me?od is illu/rat$ 9 ,figs4 #bf & #bg4 ,x is assum$ t ! plate to be bor$ is f9i%$ on ! edges1 & t x is fa/5$ to an angle-plate1 :i* is secur$ to ! table ( ! mill+ ma*9e & set squ>e ) ! sp9dle4 ,a piece ( cold-roll$ /eel or brass is fir/ fa/5$ 9 ! *uck 7:i* is m\nt$ on ! sp9dle7 & turn$ (f to any diamet]4 ,?is diamet] %\ld pref]ably be an ev5 numb] ( ?\s&?s1 to make ! calculations :i* are to foll[ easi]4 ,! turn+ c be done ei!r by hold+ ! tool 9 ! mill+ ma*9e vise1 or by secur+ x to ! table ) clamps4 ,9 ei!r case1 ! tool %\ld be locat$ ne> ! end ( ! table1 s z to be out ( ! way :5 n 9 use4 ,illu/ration3 ,fig4 #bf4 ,obta9+ ,v]tical ,adju/m5t by ,means ( ,dep? ,gage & turn$ ,plug 9 ,*uck ,aft] ! piece 9 ! *uck is tru$1 ! table & knee are adju/$ until ! c5t] ( ! sp9dle is 9 alignm5t ) ! c5t] ( ! fir/ hole to be ma*9$4 ,?is sett+ ( ! jig-plate is effect$ by measur+ ) a micromet] dep? gage f ! top & sides ( ! "w1 to ! turn$ plug1 z illu/rat$ 9 ,fig4 #bf4 ,:5 tak+ ^! measurem5ts1 ! radius ( ! plug 9 ! *uck is1 ( c\rse1 d$uct$4 ,:5 ! plate is set ! plug is remov$ f ! *uck & ! fir/ hole drill$ & bor$ or ream$ to its prop] size4 ,we %all assume t ! holes are to be locat$ z %[n by ! detail view1 ,fig4 #bf1 & t hole ,a is ! fir/ "o bor$4 ,! plug is !n aga9 ins]t$ 9 ! *uck & tru$ ) ! tool1 aft] :i* x is set opposite ! place :]e ! second hole ,b is to be bor$2 ?is is done by ins]t+ an accurately fitt+ plug 9 hole ,a & measur+ f ?is plug to ! turn$ piece 9 ! *uck1 ) an outside micromet] z indicat$ 9 ,fig4 #bg4 ,all[ance is1 ( c\rse1 aga9 made = ! radii ( ! two plugs4 ,! horizontal measurem5t c be tak5 f ! side ( ! "w ) a dep? gage z be=e4 ,! plug is !n remov$ & ! hole drill$ & bor$ to ! prop] size4 ,! plug is aga9 ins]t$ 9 ! *uck & turn$ true2 ! table is !n mov$ v]tically to a position midway betwe5 ,a & ,b1 & !n horizontally to ! prop] position = hole ,c1 z indicat$ by ! dep? gage f ! side ( ! "w4 ,! location c be v]ifi$ by measur+ ! c5t] di/ances x ) ! micromet]4 ,9 a simil> mann] holes ,d1 ,e1 ,f & ,g are accurately locat$4 ,illu/ration3 ,fig4 #bg4 ,adju/+ = ,c5t]-to-c5t] ,di/ance by use ( ,plugs & ,micromet] ,if ! prop] all[ances are made = ! v>iation 9 ! size ( ! plug1 :i*1 ( c\rse1 is made small] ea* "t x is tru$1 & if no mi/akes are made 9 ! calculations1 ?is me?od is v accurate4 ,c>e %\ld be tak5 to h ! gibs on all sides fairly tight at ! beg9n+1 & ^! %\ld n be tight5$ aft] ea* consecutive alignm5t1 z ?is g5]ally ?r[s ! "w out a few ?\s&?s4 ,if ! r$uctions 9 ! size ( ! plug1 ea* "t x is turn$1 are confus+1 new plugs c be us$ ea* "t a te/ is made1 or ! end ( ! orig9al plug c be cut (f s t x c be turn$ to ! same diamet] = e te/4 ,if ! c5t] di/ances x are n giv51 x is1 ( c\rse1 f> m conv5i5t to make all ! geometric calculations be=e />t+ to "w4 ,! ,button-&-plug ,me?od ,! use ( ! button me?od z appli$ to ! mill+ ma*9e1 is illu/rat$ 9 ,fig4 #bh1 :]e a pla9 jig-plate is %[n set up = bor+4 ,! jig1 ) buttons ,b accurately locat$ 9 positions correspond+ to ! holes to be bor$1 is clamp$ to ! angle-plate ,a t is set at "r angles to ! sp9dle4 ,ins]t$ 9 ! sp9dle !re is a plug ,p1 ! end ( :i* is gr\nd to ! exact size ( ! indicat+ buttons4 ,a slid+ sleeve ,s is accurately fitt$ to ?is plug & :5 ! "w is to be set = bor+ a hole1 ! table & knee ( ! ma*9e are adju/$ until ! sleeve ,s w pass ov] ! button repres5t+ ! location ( ! hole1 :i* br+s ! button & sp9dle into alignm5t4 ,:5 sett+ ! button 9 alignm5t1 all lo/ motion or backla% %\ld be tak5 up 9 ! fe$-screws4 ,= in/ance1 if ! button on ! jig %\ld be a little high] ?an ! plug 9 ! sp9dle1 d n l[] ! knee until ! bu%+ slips ov] ! button1 b l[] ! knee m ?an is requir$ & !n raise x until ! bu%+ w pass ov] ! button4 ,?is same rule %\ld be foll[$ = longitud9al adju/m5ts4 ,illu/ration3 ,fig4 #bh4 ,accurate ,me?od ( ,align+ ,sp9dle ) ,button on ,jig-,plate ,aft] ! button is set by ?is me?od1 x is remov$ & ! plug 9 ! sp9dle is replac$ by a drill & !n by a bor+-tool or ream] = f9i%+ ! hole to size4 ,9 a simil> mann] ! "w is set = ! rema9+ holes4 ,! plug ,p = ! sp9dle mu/ be accurately made s t ! out] end is conc5tric ) ! %ank1 & ! latt] %\ld always be ins]t$ 9 ! sp9dle 9 ! same relative position4 ,) a reasonable degree ( c>e1 "w c be set ) consid]able precision by ?is me?od1 provid+1 ( c\rse1 ! buttons are prop]ly set4 ,"s toolmak]s use1 in/ead ( ! plug & sleeve ref]r$ to1 a te/ indicator = sett+ ! buttons conc5tric ) ! ma*9e sp9dle4 ,?is indicator is atta*$ to & revolves ) ! sp9dle1 :ile ! po9t is br\ght into contact ) ! button to be set4 ,! difficulty ( see+ ! po9t] z x turns is a disadvantage1 b ) c>e accurate results c be obta9$4 ,size ,block & ,gage ,me?od ,ano!r me?od :i* c at times be employ$ = accurately locat+ a jig-plate 9 diff]5t positions on an angle-plate1 is %[n 9 ,fig4 #bi4 ,! angle-plate is1 ( c\rse1 set at "r angles to ! sp9dle & dep? gages & size blocks are us$ = measur+ directly ! am\nt ( adju/m5t4 ,bo? ! angle-plate & "w %\ld h f9i%$ surfaces on two sides at "r angles to ea* o!r1 f :i* measurem5ts c be tak54 ,aft] ! fir/ hole has be5 bor$1 ! plate is adju/$ ! requir$ di/ance bo? horizontally & v]tically1 by us+ micromet] dep? gages1 :i* %\ld pref]ably be clamp$ to ! angle-plate4 ,if ! capacity ( ! gages is exce$$1 measurem5ts may be tak5 by us+ /&>d size blocks 9 conjunction ) ! dep? gages4 ,illu/ration3 ,fig4 #bi4 ,locat+ ,"w f ,edges ( ,angle-,plate by means ( ,dep? ,gages & ,size ,blocks ,x is frequ5tly necess>y to bore holes 9 ca/ jig-plates or ma*9e p>ts1 :i* ei!r h irregul>ly %ap$ or unf9i%$ edges4 ,a good me?od ( locat+ su* "w is illu/rat$ 9 ,fig4 #cj4 ,! "p to be bor$ is atta*$ to an auxili>y plate ,a :i* %\ld h p>allel sides & at lea/ two edges :i* are /raight & at "r angles to ea* o!r4 ,?is auxili>y plate ) ! "w1 is clamp$ aga9/ an accurate angle-plate ,b1 :i* %\ld be set squ>e ) ! axis ( ! ma*9e sp9dle4 ,a p>allel /rip is bolt$ to ! angle-plate & ! inn] edge is set squ>e ) ! ma*9e table4 ,aft] ! fir/ hole is bor$1 ! "w is locat$ = bor+ ! o!r to ! edge ( ! auxili>y plate1 & horizontal measurem5ts y betwe5 ! p>allel & ! plate4 ,^! measurem5ts1 if q l>ge1 might be tak5 ) micromet] gages1 :]eas1 = comp>atively small adju/m5ts1 size blocks might be m conv5i5t4 ,v]ni] ,height ,gage & ,plug ,me?od ,:5 a v]ni] height gage is available1 x c (t5 be us$ to advantage = sett+ "w prep>atory to bor+ 9 a mill+ ma*9e4 ,"o advantage ( ?is me?od is t x requires little 9 ! way ( special equipm5t4 ,! "w is m\nt$ on an angle-plate or directly on ! plat51 dep5d+ on its =m1 & at "o end an angle-plate is set up ) its face p>allel to ! sp9dle4 ,an accurately f9i%$ plug is ins]t$ 9 ! sp9dle & ?is plug is set v]tically f ! plat5 & horizontally f ! end angle-plate1 by measur+ ) ! v]ni] height gage4 ,aft] ! plug is set = ea* hole1 x is1 ( c\rse1 remov$ & ! hole drill$ & bor$ or ream$4 ,illu/ration3 ,fig4 #cj4 ,me?od ( ,hold+ & ,locat+ ,ca/+ ( ,irregul> ,%ape1 = ,bor+ ,holes ,! way ! plug & height gage is us$ is cle>ly illu/rat$ 9 ,figs4 #ca & #cb4 ,! "w1 9 ?is p>ticul> case1 is a small jig4 ,?is is clamp$ directly to ! ma*9e table & at "o end an angle-plate is also bolt$ to ! table4 ,?is angle-plate is fir/ set p>allel ) ! trav]se ( ! saddle or 9 l9e ) ! ma*9e sp9dle4 ,to secure ?is alignm5t1 an arbor is ins]t$ 9 ! sp9dle & a te/ indicator is clamp$ to x by gripp+ ! indicator betwe5 bu%+s plac$ on ! arbor4 ,! table is !n mov$ longitud9ally until ! contact po9t ( ! indicator is aga9/ ! surface plate2 !n by trav]s+ ! saddle crosswise1 any lack ( p>allelism betwe5 ! surface ( ! angle-plate & ! l9e ( saddle trav]se w be %[n by ! indicator4 ,illu/ration3 ,fig4 #ca4 ,mak+ a ,v]tical ,adju/m5t by ,measur+ to ,gr\nd ,plug 9 ,sp9dle ,illu/ration3 ,fig4 #cb4 ,mak+ a ,horizontal ,adju/m5t by measur+ f ,angle-,plate to ,gr\nd ,plug ,:5 ! "w is to be adju/$ horizontally1 ! v]ni] height gage is us$ z %[n 9 ,fig4 #cb1 ! base ( ! gage re/+ on ! angle-plate & ! measurem5t be+ tak5 to an accurately gr\nd & lapp$ plug 9 ! sp9dle4 ,= v]tical adju/m5ts1 ! measurem5ts are tak5 betwe5 ?is gr\nd plug & ! ma*9e plat5 z 9 ,fig4 #ca4 ,locat+ ,holes to be ,bor$ f ,c5t]-pun* ,m>ks ,! problem ( accurately locat+ holes to be bor$ on ! mill+ ma*9e has receiv$ mu* att5tion1 & ! me?od g5]ally us$ :5 accuracy has be5 requir$ is ! button me?od1 :i* 0 previ\sly describ$4 ,s mu* "t is requir$ = do+ ! "w by ?is me?od1 h[ev]1 t num]\s ef=ts h be5 made to obta9 equally good results 9 o!r ways4 ,illu/ration3 ,fig4 #cc4 ,diagram ,illu/rat+ ,rapid b ,accurate ,me?od ( ,locat+ ,holes to be bor$ on ,mill+ ,ma*9e ,! increas+ dem& = rapidity comb9$ ) accuracy & a m9imum liability ( error1 l$ to ! developm5t ( ! sy/em describ$ 9 ! foll[+3 ,a c5t]-pun* m>k takes ! place ( ! button1 f :i* to indicate ! "w into ! prop] position = bor+4 ,! fundam5tal pr9ciple involv$ is to lay out1 accurately1 two l9es at "r angles to ea* o!r1 & correctly c5t]-pun* ! po9t :]e !y int]sect4 ,) prop] c>e1 l9es may be drawn ) a v]ni] height gage at "r angles1 ) extreme accuracy1 ! *ief difficulty be+ to accurately c5t] ! l9es :]e !y cross4 ,= semi-accurate "w ?is may be done ) a common c5t]-pun* b :]e extreme accuracy is requir$ ?is me?od is n applicable1 z ! av]age man is incapable ( m>k+ ! po9t ( int]section accurately4 ,! diagram1 ,fig4 #cc1 illu/rates1 9 a simple way1 ! proc$ure adopt$ 9 lay+ out "w by ?is sy/em4 ,! base ,e is 9 contact ) a surface plate :ile ! l9e ,,bb is drawn ) a height gage2 !n ) side ,f on ! plate ! l9e ,,aa is drawn4 ,x w be se5 t ^! l9es w be at "r angles to ea* o!r1 if ! bases ,e & ,f are squ>e4 ,"w done by ?is me?od mu/ h two work+ surfaces or base l9es1 & ^! mu/ be at "r angles to ea* o!r4 ,!re is no difficulty 9 draw+ ! locat+ l9es ,,aa & ,,bb correctly1 ei!r ) a v]ni] height gage or ) a special micromet] gage read+ to #j4jjja in*1 ! only difficult elem5t be+ to accurately c5t]-pun* ! l9es :]e !y int]sect z at ,d4 ,x is assum$ t two holes are to be bor$1 s t ! int]section at ,c w\ld also be c5t]-pun*$4 ,! scrib] po9t ( ! height gage %\ld be gr\nd s t x w make a ,v-%ap$ l9e1 z %[n by ! enl>g$ sket* ,g1 r ?an "o :i* w\ld resemble a saw-too?1 z at ,h1 if a cross-section ( x 7 exam9$ ) a microscope4 ,?is is important because :5 ! l9es are ,v-%ap$1 an accurate po9t ( int]section is obta9$4 ,illu/ration3 ,fig4 #cd4 ,c5t] ,locat+ ,pun* ,illu/ration3 ,fig4 #ce4 ,c5t] ,enl>g+ ,pun* ,z x is q or almo/ impossible to accurately c5t]-pun* ! int]section ( ev5 two correctly drawn l9es1 by ord9>y means1 ! pun* %[n 9 ,figs4 #cd & #cf 0 design$ & an ext5d$ exp]i5ce ) x on a v high grade ( "w has demon/rat$ its value = ! purpose4 ,x consi/s ess5tially ( a small c5t]-pun* ,o 7,fig4 #cf7 held 9 v]tical position by a hold] ,p :i* is knurl$ to facilitate h&l+4 ,great c>e %\ld be ex]cis$ 9 mak+ ?is tool to h ! body ( ! pun* /raight1 & to h x /& at "r angles to ! surface to be op]at$ ^u1 = ! slighte/ incl9ation w cause ! f9i%$ hole to be incorrect1 no matt] h[ c>efully ! l9es are drawn4 ,! #fj-;degree po9t mu/ be gr\nd true ) ! axis4 ,! hold] = ! pun* /&s on ?ree legs1 locat$ z indicat$1 & gr\nd accurately to a tap] fit 9 ! hold]1 :]e !y are secur$ by wat* screws be>+ on _! tops4 ,! l[] ends are h>d5$1 & t]m9ate 9 an angul> po9t ( #ee degrees 7! po9t ( ! v]ni] scrib] be+ #fj degrees74 ,! edges are %>p1 & slightly r\nd$ at ! ends1 s t ! legs w slide along a l9e smoo?ly4 ,! po9ts ,v & ,u 7,fig4 #cf7 h edges t are 9 l9e ) ea* o!r1 :ile ! po9t ,t has an edge at "r angles to ! o!r two4 ,! c5t] ( ! pun* is locat$ at equal di/ances f all ! legs1 & is held (f ! "w normally by a lea!r friction act$ ^u by a set-screw 9 ! side ( hold] ,p4 ,illu/ration3 ,fig4 #cf4 ,section ( ,c5t] ,locat+ ,pun* ,illu/ration3 ,fig4 #cg4 ,section ( ,c5t] ,enl>g+ ,pun* ,if ?is tool is plac$ ^u l9es ( ! =m %[n at ,g1 ,fig4 #cc1 ! legs ,v & ,u may be slid along horizontal l9e ,b-,b1 ,fig4 #cc1 until ! %>p edge ( leg ,t drops into l9e ,a-,a4 ,:5 ?is occurs ! pun* ,o is lightly tapp$ ) a hamm]1 & ! result+ m>k w be accurately locat$ 9 ! c5t] ( ! int]section ( ! l9es4 ,x is good practice to make ! "w v smoo? be=e draw+ ! l9es1 & aft] lay+ !m out1 to /one !m s z to remove ! slight burr rais$ 9 draw+ !m4 ,a drop ( oil is !n rubb$ into ! l9es1 & ! surplus wip$ (f4 ,?is proc$ure p]mits po9ts ,v & ,u to run v smoo?ly along ! l9e1 & ! burr hav+ be5 remov$1 ! edge ( leg ,t drops into ! l9e v readily ) a slight click4 ,z x is n advisable to /rike pun* ,o m ?an a v light bl[1 x m>ks ! "w b slightly1 & a m di/9ct ind5tation is made ) ! foll[] pun* %[n 9 ,figs4 #ce & #cg4 ,?is pun* is made l ! previ\s "o1 s t x w /& at "r angles to ! "w4 ,! sectional view 7,fig4 #cg7 %[s ! pun* ,a support$ by ! hold] ,e :i* has f\r legs cut away on ! sides s t ! po9t ( ! pun* may be se54 ,:5 ?is pun* is 9 position1 x is /ruck a suffici5tly heavy bl[ to make a di/9ctly visible m>k4 ,! "w is n[ ready to be plac$ ^u ! "w table ( ! mill+ ma*9e1 & indicat$ = bor+ ! holes1 an indicator be+ us$ 9 ! mill+ ma*9e sp9dle4 ,illu/ration3 ,fig4 #ch4 ,indicator us$ = ,align+ ,pun* ,m>ks ) ,ma*9e ,sp9dle ,an indicator :i* has be5 f\nd especially valuable = ?is purpose is %[n 9 ,figs4 #ch & #ci4 ,x is ( ! conc5tric c5t]+ type1 & ) x ! "w is br\ght conc5tric ) ! axis ( ! sp9dle4 ,! arbor ,i is provid$ ) a ?read$ nose on :i* disk ,d is screw$4 ,?is disk has f\r holes 9 its rim1 equally-spac$ f ea* o!r4 ,h>d5$1 gr\nd1 & lapp$ bu%+s b are put into ^! holes to receive plug ,a :i* is made a gage-fit bo? 9 ^! holes & 9 hole ,b 9 ! out] end ( sector ,c4 ,?is sector is held by a split sleeve to ! b>rel ,l :i* c>ries ! #fj-;degree c5t]+-rod ,k t comes into contact ) ! "w to be bor$4 ,! sph]ical base ( b>rel ,l fits into a correspond+ concave seat 9 ! nose ( ! arbor at ,h1 & is held 9 place by a spr+ ,e :i* connects at "o end to ! cyl9drical /ud 9 ! base ( ! b>rel1 & at ! o!r to ! axial rod ,m by :i* x & ! o!r connect+ p>ts may be drawn into place1 & held by ! headless set-screw ,j1 be>+ on a flat spot on ! tang end ( ! rod4 ,n[1 if plug ,a is remov$ f bu%+ b ! po9t ( ! c5t]+-rod ,k may be made to describe a circle4 ,at "s po9t )9 ?is circle is locat$ ! c5t]-pun* m>k on ! "w to be bor$4 ,! holes 9 ! rim ( ! faceplate all be+ exactly ! same di/ance f an axial l9e ?r\gh bo? ! arbor ,i & c5t]+-rod ,k1 x foll[s t ! c5t] m>k on ! "w mu/ be s locat$ by horizontal & v]tical movem5ts ( ! "w table t p9 ,a may be freely ent]$ 9 all ! f\r holes 9 ! rim ( disk ,d4 ,:5 t occurs1 ! c5t] co9cides ) ! axis ( ! sp9dle4 ,! po9t ( ! c5t]-pun* ,a 7,fig4 #cg7 %\ld h an angle slightly great] ?an ! angle on ! c5t]+-rod ,k1 z x is impossible to locate ! "w 9 ! prelim9>y trials s t ! c5t] ( ! "w w be co9cid5t ) ! axis ( ! sp9dle1 & unless ! precaution m5tion$ is tak51 ! true c5t] on ! "w is liable to be drawn f its prop] location :5 try+ to br+ ! "w into su* a position t ! plug w ent] all ! holes 9 ! disk4 ,z ! "w be+ op]at$ on is br\ght ne>] to ! prop] location by ! movem5ts ( ! mill+ ma*9e table1 spr+ ,g w be compress$1 ! c5t] rod slid+ back into b>rel ,l4 ,?is spr+ is made s t x w hold ! c5t] aga9/ ! "w firmly1 b )\t int]f]+ ) ! free rotation ( ! sector ,c ar\nd disk ,d4 ,:5 ! "w is locat$ s t ! plug ent]s ! holes1 ! gibs ( ! ma*9e %\ld be tight5$ up & ! plug tri$ once m1 to make sure t ! knee ( ! ma*9e has n mov$ suffici5tly to cause ! "w on ! table to be out ( l9e4 ,! "w table is n[ clamp$ to prev5t accid5tal horizontal %ift+1 & ! "w is drill$ & bor$4 ,illu/ration3 ,fig4 #ci4 ,sectional ,view ( ,indicator %[n 9 ,fig4 #ch ,9 us+ ?is indicator ! mill+ ma*9e sp9dle is n rotat$ toge!r ) arbor ,i1 only ! sector be+ turn$ ar\nd ! disk4 ,! tool is set1 h[ev]1 9 ! beg9n+1 s t ! axes ( two ( ! bu%+s b are at "r angles to ! horizontal plane ( ! ma*9e table1 :ile ! axes ( ! o!r holes 9 ! disk are p>allel ) ! top ( ! "w table4 ,! c5t]+-rods are made int]*angeable & ( v>i\s l5g?s1 to rea* m or less accessible c5t]s4 ,fig4 #ch %[s ! indicator ) "o ( ! long c5t]-rods 9 ! =egr\nd4 ,! only "p ( ! mill+ ma*9e on :i* dep5d5ce mu/ be plac$ = accuracy is ! hole 9 ! sp9dle1 & ?is is less liable to get out ( tru?1 f we> su* z w\ld impair ! accuracy1 ?an are ! knee1 table1 or micromet] screws4 ,! only mov+ "p is ! sector1 & ?is1 be+ light1 is v s5sitive4 ,a s]ies ( #bd holes 0 laid out & bor$ 9 "o & "o-half day by ! me?od describ$ 9 ! =ego+4 ,measurem5ts across accurately lapp$ plugs 9 ! holes1 %[$ ! greate/ deviation f tru? to be #j4jjjb in*1 & runn+ f t to accuracy s great t no error 0 measurable4 ,?is same "w ) buttons w\ld h requir$ consid]ably m "t4 ,illu/ration3 ,,ma*9]y ,ma*9]y is ! lead+ j\rnal 9 ! ma*9e-build+ field & meets ! requirem5ts ( ! me*anical eng9e]1 sup]9t5d5t1 design]1 toolmak] & ma*9i/1 z no o!r j\rnal does4 ,,ma*9]y deals exclusively ) ma*9e design1 tool design1 ma*9e con/ruction1 %op practice1 %op sy/ems & %op managem5t4 ,! read+ matt] 9 ,,ma*9]y is writt5 by practical m5 & edit$ by me*anical m5 ( long practical tra9+4 ,ea* numb] ( ,,ma*9]y conta9s a v>iety ( articles on ma*9e %op practice4 ,^! articles include c>efully prep>$ descriptions ( manufactur+ me?ods & curr5t me*anical developm5ts4 ,%op sy/ems & %op managem5ts are ably h&l$ by ! =emo/ writ]s4 ,e numb] conta9s ! mo/ ext5sive & complete record publi%$ by any j\rnal1 or 9 any =m1 ( new ma*9]y & tools & accessories = ! ma*9e %op4 ,a special dep>tm5t is devot$ to 8,lett]s on ,practical ,subjects10 to :i* practical me*anics contribute _! exp]i5ces4 ,!re is a dep>tm5t ( ,%op ,k9ks--brief1 concise little contributions :i* conta9 ideas ( value to ! man 9 ! %op or at ! draft+ table4 ,! me*anical eng9e]1 ma*9e design] & draftsman are also well provid$ = 9 ,,ma*9]y4 ,e numb] conta9s articles on ! !ory & practice ( ma*9e design1 on ! prop]ties ( mat]ials1 & on labor-sav+ me?ods & sy/ems4 ,!re are reviews ( rese>* "w 9 ! me*anical field1 & valuable results ( c>efully made exp]im5ts are record$4 ,! supremacy ( ,,ma*9]y 9 ! me*anical field is due to ! c>e ) :i* all matt] (f]$ = publication 9 its pages is scrut9iz$4 ,only ! be/ ( ! mat]ial (f]$ by me*anical writ]s is publi%$1 &1 z a result1 its pages conta9 ! mo/ au?oritative1 practical & up-to-date me*anical in=mation4 ,,ma*9]y1 #adj-adh ,lafayette ,/reet1 ,new ,york ,city #ea & #eb1 ,,*anc]y ,,lane1 ,,london1 ,w4 ,c4 ,heat-,treatm5t ( ,/eel ,illu/ration is "o ( a s]ies ( high-class au?oritative1 attractive & well-b\nd books publi%$ by ,,ma*9]y4 ,! /ronge/ claim t c be made = ^! books is t !y h all ! *>act]i/ics ( ,,ma*9]y itself4 ,^! books cov] compreh5sively1 & 9 a ?or\ghly practical mann]1 ! mo/ important subjects 9 ! metal-work+ field4 ,ea* book comprises ab\t #cjj pages1 pr9t$ on high-grade pap]1 ) engrav+s ( ! same sup]ior type t has made ,,ma*9]y di/9ctive 9 its field4 ,! price ( ea* book is #b4ej4 ,special comb9ation (f]s on a mon?ly paym5t plan w be s5t ^u reque/4 ,,ma*9]y #adj-adh ,lafayette ,/4 ,new ,york ,city #ea & #eb1 ,*anc]y ,lane1 ,london1 ,w4 ,c4 ,! ,five ,new ,books ,br\ght ,out by ,,ma*9]y ,,spur ,,& ,,bevel ,,ge>+ ,a treatise on ! pr9ciples1 dim5sions1 calculation1 design & /r5g? ( spur & bevel ge>+1 toge!r ) *apt]s on special too? =ms & me?ods ( cutt+ ge> tee?4 ,,spiral ,,& ,,worm ,,ge>+ ,a treatise on ! pr9ciples1 dim5sions1 calculation & design ( spiral & worm ge>+1 toge!r ) *apt]s on ! me?ods ( cutt+ ! tee? 9 ^! types ( ge>s4 ,,turn+ ,,& ,,bor+ ,by ,,frankl9 ,d4 ,,jones ,associate ,editor ( ,,ma*9]y ,a specializ$ treatise = ma*9i/s1 /ud5ts 9 indu/rial & eng9e]+ s*ools1 & appr5tices on turn+ & bor+ me?ods1 includ+ mod]n practice ) eng9e la!s1 turret la!s1 v]tical & horizontal bor+ ma*9es4 ,,plan+ ,,& ,,mill+ ,by ,,frankl9 ,d4 ,,jones ,associate ,editor ( ,,ma*9]y ,a treatise on ! use ( plan]s1 %ap]s1 slott]s & v>i\s types ( horizontal & v]tical mill+ ma*9es & _! atta*m5ts4 ,,heat-,,treatm5t ,,( ,,/eel ,a compreh5sive treatise on ! h>d5+1 temp]+1 anneal+ & case-h>d5+ ( v>i\s k9ds ( /eel1 includ+ high-spe$1 high-c>bon1 alloy & l[-c>bon /eels1 toge!r ) *apt]s on heat-treat+ furnaces & on h>dness te/+4 ,price ( ea* book #b4ej4 ,special comb9ation (f]s on a mon?ly paym5t plan w be s5t ^u reque/4 ,,ma*9]y #adj-adh ,lafayette ,/4 ,new ,york ,city #ea & #eb1 ,*anc]y ,lane1 ,london1 ,w4 ,c4