REPRAP MAGAZINE WWW.REPRAPMAGAZINE.COM Practical exploration of 3D printing Issue 1 Interviews - Pro tips - Reviews Diy projects - Tutorials - Galleries February 2013 Issue 1 Interviews - Pro tips - Reviews Diy projects - Tutorials - Galleries February 2013 Slicer review & comparison Interview with Adrian Bowyer Repetier part 1: Communication Taxonomy of Z axis artifacts Issue nº 1
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printedparts-willhavethedesignfilesmadeavailableforpeopletosourcethemselves.Heisalsoexpectingtoselltherequiredcompo-nentsviaaweb-shop,andisconsideringdoingafundingcampaigntobringtheprintertoawideraudienceatthebestpricepossible. ThecurrentversionconsistsofeletronicsbasedonaArduinoshield,alaRAMPS,whitchcontrolthelasergalvanometers.Thisisbeingredesignedintoamoreeffcient, and cheaperstandaloneboardwiththehelpofRepRapregular,Kliment.AcustomversionofMarlinprovidesthefirmware.
Hethenspenttwenty-twoyearsasa lecturerthensenior lecturer intheMe-chanicalEngineeringDepartment at theUniversity ofBath.He retired fromacademiclifein2012,thoughheisstilladirectorofthecompanyRepRapPro-fessionalLtd.HeinventedtheRepRapProject-anopen-sourceself-replicating3Dprinter.TheGuardiansaidofthis,"[RepRap]hasbeencalledtheinventionthatwillbringdownglobalcapitalism,startasecondindustrialrevolutionandsavetheenvironment..."[
AdrianBowyerFromWikipedia,thefreeencyclopedia
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InterviewAdrian Bowyer
Interview with
Adrian Bowyer
The RepRap project started at Bath University, how exactly did it come about? Did the idea originate from yourself or did it come out of discussions with the University?
1. Ihavebeen interested in the ideaofartificialreplicatorssincechildhood. Ican’trememberwherethatcamefrom.
2.Aroundtheturnofthecentury,BathUniversitygotanequipmentgrant,andIsug-gestedthattheyspenditontwo3Dprinters.Thiswas nothing to dowith Item1. - I justwantedaccesstothemtomakethings.
6.AlmostassoonasIhadtheideaIre-alisedthatitwasverypowerful,andthattheonlyway to prevent that power from fallingintothewronghandswastogiveittoevery-one.
7.Literallyminutesafter I thought thatIrealisedthatyouhavetogiveanyself-rep-licating device away anyway, otherwise youputyourselfinaneternalbattletryingtostoppeopledoingwithyour idea theone thing itwasintendedtodo.
In the interest of others who may wish to at-tempt something similar, how did you convince the University to support the project? Was the indirect educational effect suffcientt
ItoldthemwhatIwasgoingtodo.Aca-demicfreedommeans(interalia)thattheindi-vidualacademichasabsolutediscretionoverhowtheydisseminatetheresultsoftheirre-search.Itisusuallyacademiccupidity(ratherthan Universities’ bureaucracy) that causesacademicsto,forexample,pursuepatentsbe-forepublication. Butanyway,myUniversitywashappywithmydecision,whichmore-or-lesscametothemasafaitaccompli.
What does your recent retirement from the Uni-versity entail for the project there? Will it continue under the direction of other staff and the students or will it be closed down?
There are other staff still pursuing as-pectsoftheproject. Mostofthiswork isofthe form “Application of RepRap to ProblemX”.
The project started with several key tenets which marked it as unique amongst perhaps similar endeavours (the DIY CNC scene for example), namely: the goal of self-replication; the GPL; and the “Wealth Without Money” essay. These, together with the pro-ject’s academic roots, defined the project as part of a much wider, more ambitious and perhaps philosophi-cal, scheme. Considering the recent commercialisa-tion, and associated hype, surrounding 3D printing, do you feel that this is a natural phase for the project to be going through, and one that ultimately supports the original goals? Or do you feel this is a distraction which must be endured before the project regains its original focus?
Moretheformerthanthelatter.Ialwaysthought that, if RepRap went anywhere, itwouldbecomeparasiticoncommerce. An old friend ofmine is highly amusedwheneverhevisitsandIsay,“IjusthavetogoandsettheRepRapsprinting.Won’tbelong.”
“Yourpredictionhascometrue,”hesays.“You always said that RepRapwould entrappeoplebymakingthemwanttoassistittorep-licate.Andithasenslaveditsveryinventortothatend,printingitself-asheseesit-forthebenefitofhiscompany.Whereasinrealitythecompanyisforthebenefitofthemachine.”
Are the original goals of the project (self-repli-cation, disruption of traditional means of production) still relevant, or necessary, now that the project has reached the stage it has?
Self-replication was, and remains, theprimarygoal,formeatleast.Itisthegoaltowhicheveryotherpossiblesub-goalisneces-sarilysubservient.Thepotentialdisruptionsarenot really evengoals;moreby-products.Thespreadofthemachineisprettymuchdo-ingwhatIthoughtitwould.
RepRap is a major part of the current “maker revolution”, either directly (spin-offs such as Maker-bot), or indirectly (inspiring and enabling Open Hard-ware projects). What aspect or challenge needs to now be accomplished for RepRap to maintain this po-sition within the DIY 3D printer and maker commu-nity?
Did you imagine back in 2004 that the RepRap project would gain such global success? Has the sub-sequent growth lived up to your expectations?
At the start I thought it was 50/50: itwould either sinkwithout trace, or go spec-tacularlyglobal.Itseemedtomethatitsin-herentlyexponentialnaturewouldnotadmitofanypointbetweenthosetwo;abifurcationwasinevitable.
Thecointosscamedownheads.
The evolutionary process is sometimes used to describe the project. Considering that the RepRap project is a machine that aims for self replication, and has an evolution comparable to living species (sur-vival of the fittest, evolutionary dead ends, etc.), in your opinion what is the place that RepRap holds in the food-chain of the 21st Century manufacturing en-vironment? Who is its main predator and its favourite prey? I’maimingforthebottom:I’dmuchrath-eritwasabacteriumthanaleopard-leopards(asaspecies)arenotaroundforlong.
The project The organisational aspects of the project, or lack of, has always been controversial, with many wanting more control and direction, and many preferring the slightly chaotic nature. It was recently described as an Adhocracy, which I feel is a wonderfully accurate description. Do you feel that the decentralised na-ture of the project has contributed to its success?
Ihavenoidea.ButIcertainlydon’tthinkthatwewouldseethewonderfulrobustspe-ciationthathasoccurred,withmanydifferentRepRapdesignsoutthere, if theprojecthadbeenmorecontrolled.Ratherthereverse.
Considering this decentralised nature of the project, do you feel that having such terms as “Core Developers” goes against it? Would the project be better off now disbanding this teamt or replacing it with another form of representation?
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I really have no strong opinions aboutthis. Indeed,oncareful introspection,IfindthatIhavenoopinionsatall.
Do you feel that the future of the project is now safely in the hands of the wider maker community and that RepRap will live on through it? Or do you feel there is a need for some form of foundation to un-derpin the core principles of the project, as originally envisioned?
Again,Ihavenoidea.
Thepsychologiststellusthat,ifyouwouldknowthefutureofsomething,itisworthlesstoconsultanexpertonthatthing.Financiersknownothingaboutwhereeconomieswillgo;agriculturalists know nothing about whereglobalfoodproductionwillgo,andsoon.Inevery study on this ever conducted, expertsinafieldarenobetterpredictorsofthatfieldthanchance.Thereisoneexception:expertswhosejobitistopredict,andwhogetregu-larandimmediatefeedbackontheaccuracyof every prediction that theymake - peoplelikeweatherforecasters.Theydobetterthanchance.
Iam,IthinkIcansay,somethingofanexpertonRepRapinparticularand3Dprint-ingingeneral.SoIhavenoideawhatthebestwaytoensurethesuccessoftheprojectinthefutureis.Myperceptionisthatthewayitisorganised,andbywhom,isvanishinglyunim-portant compared to somebody’s coming upwithareallygoodnewdesignandreleasingit,but-asIsay-IknowthatIdon’tknow.
For someone new to the project, and starting to build a RepRap from scratch, what aspect do you think is the most challenging? Have you any tips or advice on how to overcome it?
technicalities-theyknowhowtogettwopartssquare,whentouseshims,whatsequencetotighten screws in and so on,without havingto thinkabout it. But they tend toflounderslightlywhenitcomestomodernelectronicswithlotsofstatic-sensitiveMOSFETSin,andtobequitebackwardwhenitcomestocompil-ingsoftware.Asyougodowntheagerangetheskillsreverse,withyoungpeoplehavingnotroublewiththecomputingaspectsofthings,butbeingquiteunsureaboutthemosttrivialofmechanicaltechniques,likehowtotightenanutthatisfacingawayfromthem.
Mybest tip forbuildingaRepRap is toformasmallteamoffriendswithcomplimen-taryskillstocoverallthosebases,ratherthandoingitonone’sown.
The future Even ignoring the current hype surrounding 3D printing, there are many exciting possibilities being explored around the world: biological tissue replica-tion, printable architecture, new materials and tech-niques, amongst many others. Many of these use RepRap as their underlying technology. Is there any particular area which really interests you personally, or you feel has the potential to become exceptionally interesting in the near future?
Yes-Ithinkthatthemostexcitingapplicationof RepRap will be in manufacturing equip-mentforpersonalbiotechnology.
For example, I suspect (see the caveatabout expert predictions above) thatwearereasonablyclosetobeingabletomakehumanspermandeggsinvitrofromstemcells.Imag-inethedisruptivepotentialofanopen-sourceRepRap-made machine into which a couplecould put two cheek swabs, one from eachof them. Themachinewoulddoa completegenetic analysis and offer them a consciouschoiceoverwhichallelefromonetocombine
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withwhich fromtheotherall thewaydownthe23 chromosomepairs,withprobabilitiesandpredictionsonthealternativephenotypi-calresults. After they’ve designed their baby, thecouplewould thenbepresentedwithan im-plantablefertilisedzygote. Vitally, the open-source RepRap-madeaspect of such a machinewouldputthechoicesentire-lyinthehandsofthecoupleconcerned and - more im-portantly-preventeveryoneelse (relatives, religions, orgovernments) from interfer-ing. Just like all the othersevenbillionofus,Ihavenoideaifthiswouldbeagoodor a bad idea, though likeallsevenbillionIdohaveaworthlessopiniononit.Butit would certainly be inter-esting.
As versatile and fun as they are, 3D printers are only one tool amidst many. Is there a place for other tools in the RepRap fam-ily? Are there other devices you would like to see with a RepRap name badge on it?
A self replicating laser cutterwould bepossibleanduseful-severalpeoplearework-ingonthat.AndMIThaveareplicatingCNCmill.ThedefinitionofthewordRepRapcer-tainly takes in such developments, thoughpeoplemustnamethemastheywill.
Throughout the project you have explored and experimented with many techniques and tools (Piezo print-head, granule extruder, mould castings). With your day job now being at RepRapPro will you con-tinue such experimenting, or is your time consumed with sales, marketing and support?
Abouthalfandhalf. I’mpleasedtosaythatRepRapProLtdmakesenoughmoneyformeandmycolleaguesnottohavetospendallour time counting springs into plastic bags.I’malsopleasedtosaythatwedon’tmakesomuchmoney that some of us never need tocountspringsintoplasticbags.
After all the time you have in-vested into RepRap, does it still excite you today?
Yes.Ithasbeen-andcon-tinuestobe-morefunthatI couldpossiblyhave imag-inedatthestart. Ignoring your self depre-cating “I know asmuch asthe next man” position foramoment,whattechnologi-calleapforwarddoyousee,orhopetosee,happeninginthe near future which willpropel RepRap to the nextlevel?
See above about ease ofassembly and multiple ma-terials.
And looking further into the future, which truly advanced, almost science fiction, technologies can you imagine RepRap consisting of? Are nano-facto-ries feasible?
I foresee a scale convergence,with thebiologistsworkingupfromthebottomandtheengineersworkingdownfromthetop.IhopethatIlivelongenoughforittobecomeimpos-sibletodistinguishbetweenthecreationsofthetwo.
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Feature separator
RepRap Gcode generators have evolved and matured to a point where we have a nice choice of features, complexity with simplicity and process-ing speeds, but what’s the ideal one for you?
It going to be sliced with the same settings but with 10% infill.This model is a complex organic shape with thick walls and minor overhangs.
Cura Test –7mins15secondstoexportthefiletoGcode–2.91MBfile-veryfastindeed!!EDIT!-CuradidnotproduceavalidGcodefile,itdidhaveastartandend,butnotvalidGcodefortheLavaVase-itjustcrashedRep Slic3r test –Slic3rcrashedafter15+minutesduring‘Generatingperimeters’Secondtryafterreducingthenumberofthreadsfrom3to2=Crashedagainatasimilarpoint,it’sprobablyrunningoutofmemoryonthiscomputer. IhadtogiveupwiththisunderWindowsXp,butitdidslicefinewiththe64bitversionofSlic3runderWindows7. KISSlicer test –After23min44seconddur-ingtheGcodeexportKISSlicercrashedwith“Assertionfailed!Ext_count>0“2.989MBofGcodewaswrittenout Second try –After38minsalltheGcodewaswrittenout156MB–unfortunatelyIhadmovedthelowersliderforsupporttobe-0thinkingthiswoulddisablesupportforthemodel,butitdidtheexactoppositeandaddedsupportevery-where! Third try – Ichangedthesupportslidertobe90degrees,andthistimetheoutputGcodewas102MBandgeneratedin26mins34seconds,nosupportstructureused.OutputGcodelooksgood. Noteonsupport–Nexttime,justusethetopslider,thisallowsyoutoswitchoffsupportcom-pletely. IprintedtheLavavasefromtheSlic3rGcodeonaRostockprinter-justover5hourstoprint.
The Lava Vase by Dizingof scaled by 150% to 270mm tall
OneofthemainfeaturesforSlic3risthatitisveryeasytouse,fastatprocessingsoyoucanmakechangestosettings,viewtheout-putcodeandseeexactlywhatthatdoestothemodelveryquickly.It’sanidealstartingpointforlearninghowyourmachineworksandwhatitcanandcan’tdo. Areas for improvement
Support structure.
Thisisatrickyareaastheslicerneedstofirstworkoutifapartofthemodelneedssup-porttobeprinted,itthenneedstoprintafinestructureundertheareaoftheobjecttoallowagentlesupportoftheactualmodelbutallowremovalofthesupportmaterialfromthemod-elwithoutleavingitstucktothepartneedingmoreaggressiveremoval.Muchmoreworkneedstobedoneonsupportmaterialusage,temperaturesettingstoallowweakerbondsandeasierremoval,andalsohopefullyatsomepointsoondissolublesupportmaterialsthatcouldbeextruderandpossiblyreusedagain. Slic3rhaslimitedsettingsforsupportanditcanputssupportmaterialinboththewrongplaceandormixedinwiththepartbe-ingprintedsoit’sveryhardtoremove,experi-mentwithcare. Different versions give very different output Gcode.
Areas for improvement TheFreeversionofKISSlicercanonlyloadonemodelatatime,soifyouwishtoprintmultipleparts,youwillneedtocom-binethemontoaplateandexportanew.STLfilesoKISSlicercanloaditasonefile.–AsanoteSlic3rcaneasilycombinemulti-ple.STLfilesandexportaplateofthepartsasasingle.STLmeaningyoucanthenloadthatintoKISSlicer. AnotherlimitationofKISSliceristhatthefreeversioncanonlyhandleoneex-truder,wherethePROlicensecandomul-tipleextrudersandloadmultiplepartsto-gether. KISSlicer’slicenseallowsyoutouseitforbothhobbyandcommercialuseaslongasyoudon’treverseengineeritasitsnotopensourcesoftware.
What is the problem? With some luck you have no problems at all. Youconnectyourprinter,settherightbaudrateandthereyougo.Ifitisthatsimplethenwhywriteacompletear-ticleonit?Well,workingisnotthesameasworkingasbestaspossible.IncombinationwithRepetier-Hostyoucanchangethecommunicationbehaviorandchangethespeedconsiderably.Butatthebeginningtakealookatfig.1,whichshowswherecommunicationoccurs,untilthesteppersaremoved.
Now you know everything about the communication, you should know. With these infor-mations, you should now be able to understand why things happen as they happen.
Check your communication flow and find the bottleneck causing your problem.
RepRap 3D printers have been around for a couple of years but if you have been miss-ing the party then this section of the magazine is here to as-sist you getting into this world in an easy way. Forthisfirsteditionwearegoingtocov-erthebasicanatomyofa3Dprinter,thework-flowofprinting,andsomeadviceonchoosingtherightmodeltofityourneeds.Butfirstletscoverthebasics. Thereareseveralpopularmodelsofprinterscurrentlyavailable,andthefactthatthereisnotonlyonepopularmodel,butsev-eral,showsyouthediversityoftheproject.Now,oneoftheaspectsthathelpsthisdiver-sityisthatforeachcomponentoftheprinteryouhavemorethanonetypetochoosefrom.Justtogiveoneexample,letsfocusontheextruder:youcanchoosefromaBowden,ageared,oradirectdriveextruder. Let’sassumewechoosethegearedex-truderwethencanchoosefromWade’sorGreg’sextruderforexample.ThiscanlookalittlebitoverwhelmingandconfusingforsomeonenewtoRepRapwhowantstosourcethepartsandbuildtheprinter,insteadofjustbuyingakit,butitcaneasilybedonewithoutmuchtrouble. Let’sstartbyunderstandingyourprinteranatomy.
As a conclusion we can say that Re-pRap is a very versatile project, that you can explore more and more as your knowl-edge grows. Probably you will run into some problems on your path, but you will also run into a community of users willing to help you solving them.