Screw-Thread Cutting by the Master-Screw Method since 1480
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Screw-Thread Cutting by the Master-Screw Method since 1480

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The Project Gutenberg EBook of Screw-Thread Cutting by the Master-ScrewMethod since 1480, by Edwin A. BattisonThis eBook is for the use of anyone anywhere at no cost and withalmost no restrictions whatsoever. You may copy it, give it away orre-use it under the terms of the Project Gutenberg License includedwith this eBook or online at www.gutenberg.netTitle: Screw-Thread Cutting by the Master-Screw Method since 1480Author: Edwin A. BattisonRelease Date: March 24, 2010 [EBook #31756]Language: English*** START OF THIS PROJECT GUTENBERG EBOOK SCREW-THREAD CUTTING SINCE 1480 ***Produced by Colin Bell, Joseph Cooper, Louise Pattison andthe Online Distributed Proofreading Team athttp://www.pgdp.netTranscriber’s Notes:This is Paper 37 from the Smithsonian Institution United States National Museum Bulletin 240, comprising Papers 34-44, which will also beavailable as a complete e-book.The front material, introduction and relevant index entries from the Bulletin are included in each single-paper e-book.Corrections to typographical errors are underlined like this. Mouse over to view the original text.SMITHSONIAN INSTITUTIONUNITED STATES NATIONAL MUSEUMBULLETIN 240Smithsonian Press LogoSMITHSONIAN PRESSMUSEUM OF HISTORY AND TECHNOLOGYContributionsFrom theMuseumof History andTechnologyPapers 34-44On Science and TechnologySMITHSONIAN INSTITUTION · WASHINGTON, D.C. 1966Publications of the United States National MuseumThe scholarly and scientific ...

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Published 08 December 2010
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The Project Gutenberg EBook of Screw-ThreadCutting by the Master-ScrewMethod since 1480, by Edwin A. BattisonThis eBook is for the use of anyone anywhere at nocost and withalmost no restrictions whatsoever. You may copy it,give it away orre-use it under the terms of the Project GutenbergLicense includedwith this eBook or online at www.gutenberg.netTitle: Screw-Thread Cutting by the Master-ScrewMethod since 1480Author: Edwin A. BattisonRelease Date: March 24, 2010 [EBook #31756]Language: English*S*C* RSETAWR-TT HORFE ATDH ICS UPTRTOINJEG CSTI NGCUET 1E4N8B0E *R**G EBOOKProduced by Colin Bell, Joseph Cooper, LouisePattison andthe Online Distributed Proofreading Team at
the Online Distributed Proofreading Team athttp://www.pgdp.netTranscriber’s Notes:TUhniits eids  SPtaapteers  3N7a ftiroonma lt hMeu sSemuitmh sBounlilaetni nI n2s4ti0t,utioncomprising Papers 34-44, which will also be availableas a complete e-book.The front material, introduction and relevant indexentries from the Bulletin are included in each single-paper e-book.Corrections to typographical errors are underlined likethis. Mouse over to view the original text.SUNMIITTEHDS OSNTIAATNE ISN NSTAITTIUOTNIAOLNMUSEUMBULLETIN 240Smithsonian Press LogoSMITHSONIAN PRESS
MUSEUM OF HISTORY AND TECHNOLOGYContributionsFrom theMuseumof History andTechnologyPapers 34-44On Science and TechnologySMITHSONIAN INSTITUTION · WASHINGTON, D.C.6691Publications of the United States National MuseumThe scholarly and scientific publications of the UnitedStates National Museum include two series,aPnrod cUeenidtiendg sS toaft tehs e NUatniitoenda l SMtautsees uNma tBiounllaelt inM.useumIn these series, the Museum publishes original articlesand monographs dealing with the collections and workof its constituent museums—The Museum of NaturalHistory and the Museum of History and Technology—setting forth newly acquired facts in the fields ofanthropology, biology, history, geology, andtechnology. Copies of each publication are distributedto libraries, to cultural and scientific organizations, andto specialists and others interested in the differentsubjects.The Proceedings, begun in 1878, are intended for the
publication, in separate form, of shorter papers fromthe Museum of Natural History. These are gathered involumes, octavo in size, with the publication date ofeach paper recorded in the table of contents of thevolume.In the Bulletin series, the first of which was issued in1875, appear longer, separate publications consistingof monographs (occasionally in several parts) andvolumes in which are collected works on relatedsubjects. Bulletins are either octavo or quarto in size,depending on the needs of the presentation. Since1902 papers relating to the botanical collections of theMuseum of Natural History have been published in theBulletin series under the heading Contributions fromthe United States National Herbarium, and since 1959,in Bulletins titled “Contributions from the Museum ofHistory and Technology,” have been gathered shorterpapers relating to the collections and research of thatMuseum.cTohem pprriessees nBt uclloellteinc ti2o4n0 .o fE aCcohn torif btuhtieosnes ,p aPpaepresr sh a3s4-44,obfe epnu bplirceavtiioouns ilsy  sphuoblwisnh oend  itnh es leapsatr pataeg feo rofm .e aTchhe  pyaepaerr.Frank A. TaylorDirector, United States National MuseumContributions fromThe Museum of History andTechnology:
Paper 37Screw-Thread Cutting by theMaster-Screw Method Since0841Edwin A. BattisonEdwin A. BattisonSMCARSETEW-RT-SHCRREEAWD  CMUETTTHIONDG  SBIYN CTEH E1480Among the earliest known examples of screw-threadcutting machines are the screw-cutting lathe of 1483,known only in pictures and drawings, and aninstrument of the traverse-spindle variety for threadingmetal, now in the Smithsonian Institution, dating fromthe late 17th or early 18th century. The author showsclearly their evolution from something quite specializedto the present-day tool. He has traced the patents forthese instruments through the early 1930’s and fromthis research we see the part played by such devicesin the development of the machine-tool industry.The Author: Edwin A. Battison is associate curator ofmechanical and civil engineering in the SmithsonianInstitution’s Museum of History and Technology.
Directness and simplicity characterize pioneermachine tools because they were intended toaccomplish some quite specialized task and the needfor versatility was not apparent. History does notreveal the earliest forms of any primitive machines nordoes it reveal much about the various early stages inevolution toward more complex types. At best we havediscovered and dated certain developments asexisting in particular areas. Whether these forms werenew at the time they were first found or how widelydispersed such forms may have been is unknown.Surviving evidence is in the form of pictures ordrawings, such as the little-known screw-cutting latheof 1483 (fig. 1) shown in Das mittelalterlicheHausbuch.This lathe shows that its builder had a keen perceptionof the necessary elements, reduced to bareessentials, required to accomplish the object. Presentare the coordinate slides often credited to HenryMaudslay. His slides are not, of course, associatedwith the spindle; neither is there any natural law whichcompels them to guide the tool exactly parallel with theaxis of revolution. In this sense the screw-cutting lathein the Hausbuch is superior because it is in harmonywith natural law and can generate a true cylinder,whereas Maudslay’s lathe can only transfer to thework whatever accuracy is built into it.In principle this machine shown in the Hausbuch isvery advanced as we see when we follow the designthrough to the present time. The artist, whosedrawings give us our only knowledge of the machine,himself was obviously not very familiar with the details
of its function. Reference to figure 1 shows that thethreads on the lead screw and on the work, wind inopposite directions. This must be an error indelineation since the two are closely coupled togetherwithout any intervening mechanism so that the onlypossible result on the work must be a thread windingin the same direction as on the original screw. Thework also is shown threaded for its entire length; thiscannot be accomplished with any one location of thecross-slide. We are left with the question of whetherthis slide was used in two locations or whether theartist, possibly working from notes or an earlier roughsketch, failed to show an unthreaded portion on oneend or the other of the work.Figure 1.— Earliest representation found of a master-screw type of thread-cutting machineFigure 1.—Earliest representation found of a master-screw type of thread-cutting machine. From theinconsistencies, such as right- and left-hand threadson master and work, it appears that the artist hadscant insight into actual function. From plate 62 of Dasmittelalterliche Hausbuch, nach dem Originale imBesitze des Fürsten von Waldburg-Wolfegg-Waldsee,im Auftrage des Deutschen Vereins fürKunstwissenschaft, herausgegeben von Helmuth Th.Bossert und Willy F. Storck (Leipzig: E. A. Seemann,1912).Of at least equal importance with the lead screw andswuoprpk oartn dw itthhe iitrs r selcarteiown-sahdijpu sttoe ed accrho sost-hselird ies  (tfhige.  t2o)o.l-Just how this was attached to the frame of the
machine so that it placed the tool at a suitable radiusis again a questionable point. The very well-developedcutting tool is sharpened to a thin, keen edge totallyunsuited for cutting metal but ideal for use on a softer,fibrous substance: undoubtedly wood, in this instance.Unfortunately, the angle at which the artist chose toshow us this cutter is not a view from which it ispossible to judge whether or not the tool has beenmade to conform to the helix angle of the thread to becut. This cross-slide, in conjunction with the traversingwork spindle, gives us a machine having twocoordinate slides yielding the same effect as the sliderest usually attributed to Henry Maudslay at the end ofthe 18th century. Actually, an illustration of coordinateslides independent of the spindle had been publishedas early as 1569 by Besson[1] and knowledge of themwidely disseminated by his popular work onmechanics. These slides are shown as part of ascrew-cutting machine with a questionably adequateconnection, by means of cords, between the masterscrew and the work.It was the author’s pleasure recently to obtain for theSmithsonian Institution and identify a small, nicelymade, brass instrument which had been in twocollections in this country and one collection inGermany as an unidentified locksmith’s tool (fig. 3).This proved to be an instrument of the traverse-spindle variety for threading metal. Fortunately, allessential details were present including a cutter (A infigure 4); this instrument was identified by thesignature “Manuel Wetschgi, Augspurg.” TheWetschgis were a well-known family of gunsmiths andmechanics in Augsburg through several generations.
Two bore the given name Emanuel: the earlier wasborn in 1678 and died in 1728. He was quitecelebrated in his field of rifle making and became chiefof artillery to the Landgrave of Hesse-Kassel shortlybefore his death in his 51st year. Little is known of thelater Emanuel Wetschgi except that he was atAugsburg in 1740. Tentative attribution of theinstrument has been made to the earlier Emanuel,chiefly on the basis of his recognized position as anoutstanding craftsman.Figure 2.— Cross-slide for the thread-cutting lathe ofDas mittelalterliche Hausbuch, shown in figure 1. It isremarkable not only for its early date, but also for itshigh state of development with a crossfeed screwwhich had not become universally accepted 300 yearslater. The cutter, shown out of its socket, is obviouslysharpened for use on wood.Figure 2.—Cross-slide for the thread-cutting lathe ofDas mittelalterliche Hausbuch, shown in figure 1. It isremarkable not only for its early date, but also for itshigh state of development with a crossfeed screwwhich had not become universally accepted 300 yearslater. The cutter, shown out of its socket, is obviouslysharpened for use on wood.In several respects this little machine differs from itspredecessor of the Hausbuch, as might be expectedwhen allowance is made for the generations ofcraftsmen who undoubtedly worked with such toolsover the roughly 200 years of time separating them.Another factor to consider when comparing these twomachines is that one was used on metal, the other
probably only on wood. Therefore, it is not surprisingto find on the later machine an outboard or “tailstock”support for the work. The spindle of this support hasto travel in unison with the work-driving spindle so thatit is not an unexpected discovery to find that it isspring-loaded. Figure 5 shows how this spring may beadjusted to accommodate various lengths of work bymoving the attachment screw to various holes in boththe spring and in the frame. Also visible in the sameillustration is a rectangular projection at the other endof the spring which engages a mating hole in the“tailstock” spindle to prevent its rotation.Figure 3.— Small thread-cutting lathe which was madeto be held in a vise during use. It was found as shownhere, with only the operating crank missing. Theoverall length is approximately 12 inches, dependingon the adjustment of parts. (Smithsonian photo46525B.)Figure 3.—Small thread-cutting lathe which was madeto be held in a vise during use. It was found as shownhere, with only the operating crank missing. Theoverall length is approximately 12 inches, dependingon the adjustment of parts. (Smithsonian photo46525B.)Figure 6 shows the traversing spindle and nutremoved from the machine. Provision has been madefor doing this so easily that there is every reason tobelieve that, originally, there were various differentspindle and nut units which could be interchangeablyused in the machine. Additional evidence tending tosupport this concept exists in the cutting tool (fig. 4),