impression3D_1UsageDomestique
π Industry π Science and technology
Where are all the 3D printers we were promised?

Why the 3D printing revolution hasn’t happened yet

On March 31st, 2021 |
5 mins reading time
1
Why the 3D printing revolution hasn’t happened yet

    Thierry Rayna
    Thierry Rayna
    Professor at École polytechnique and researcher at CNRS i³-CRG laboratory*
    Key takeaways
    • Prototyping and tooling still account for 90% of 3D printing uses.
    • Using 3D printers and associated software is still too complex for the uninitiated, who prefer to continue using traditional production methods.
    • 3D printing has qualities that are highly sought after by industry (complexity of patterns, strength of materials)... but much less so by individuals.
    • For Thierry Rayna, researcher at École polytechnique, this should change with the spread of AI and machine learning, which will enable instant, customised production of products directly by consumers.

    The so-called “dis­rup­tive” tech­nol­o­gy that is 3D print­ing, now in its thir­ties, would seem to be com­ing back into fash­ion. Yet, despite its rev­o­lu­tion­ary tech­ni­cal prop­er­ties and advan­tages, as well as very opti­mistic growth pro­jec­tions, the indus­tri­al and domes­tic uses of this tech­nol­o­gy seem to be pro­gress­ing much more slow­ly than expect­ed. As such, we are still wait­ing for the 3D print­ing rev­o­lu­tion in our day to day lives, which experts have been pre­dict­ing for years. For Thier­ry Ray­na, who has been study­ing the adop­tion and impact of addi­tive man­u­fac­tur­ing for years, this rev­o­lu­tion can­not take place with­out com­bin­ing 3D print­ing with oth­er “emerg­ing” tech­nolo­gies, such as arti­fi­cial intel­li­gence, con­nect­ed objects and aug­ment­ed reality. 

    What is 3D print­ing used for in practice?

    Thier­ry Ray­na. Broad­ly speak­ing, there are four pos­si­ble uses of 3D print­ing 1. First­ly, rapid pro­to­typ­ing appeared in the 1980s and was the only pos­si­ble use of this tech­nol­o­gy for a long time. Next, 3D print­ers start­ed to be used to design tools (moulds, cut­ting guides) for tra­di­tion­al man­u­fac­tur­ing meth­ods (known as “rapid tool­ing”). This allows the pro­duc­tion of moulds (for injec­tion mould­ing) for exam­ple, which often have a high­ly com­plex struc­ture, at a much low­er cost and much more quick­ly. Pro­duc­tion in this way allows for faster cool­ing and demould­ing, or bet­ter per­form­ing prod­ucts thanks to the pos­si­bil­i­ty of print­ing more com­plex sur­faces (Miche­lin tyres, for example). 

    The next step was the use of 3D print­ing to man­u­fac­ture objects (or parts of them) direct­ly, which offers a real cost advan­tage. As no tools are required for man­u­fac­tur­ing (no moulds, etc.), the cost remains con­stant, and objects can be pro­duced in very small series. 

    The final step is on-demand pro­duc­tion car­ried out local­ly or even direct­ly “at home” by con­sumers. This takes us from a sit­u­a­tion in which pro­duc­tion is based on esti­mat­ed demand (hence the poten­tial for waste), to one in which only what is need­ed is pro­duced, with trans­porta­tion being reserved for raw mate­ri­als only. Indeed, the cost per unit in 3D print­ing is con­stant so there is much less rea­son to con­cen­trate pro­duc­tion geo­graph­i­cal­ly or tem­po­ral­ly as is cur­rent­ly the case. 

    This final appli­ca­tion is what we tend to imag­ine when think­ing about 3D print­ing: domes­tic-use. But it should be not­ed that pro­to­typ­ing and tool­ing still account for ~90% of the uses of the tech­nol­o­gy. Direct man­u­fac­tur­ing and “at home” pro­duc­tion are (as yet) not widespread.

    3D print­ed bicy­cle frame ©Thier­ry Rayna

    Why do you think 3D print­ing has not found its place in our every­day life yet? 

    It has in fact already been inte­grat­ed into our lives for cer­tain uses: pro­to­typ­ing and tool­ing, but these uses are not very vis­i­ble and are rel­a­tive­ly non-dis­rup­tive. For the rest, and despite the sig­nif­i­cant advan­tages of 3D print­ing, we are still look­ing for uses, both domes­tic and indus­tri­al, that real­ly make sense. 

    For the moment, 3D print­ing is still com­pet­ing with oth­er man­u­fac­tur­ing tech­nolo­gies, which are undoubt­ed­ly less “mod­ern” but high­ly opti­mised. In fact, even though “direct man­u­fac­ture” of objects (i.e., local) is the most trans­for­ma­tive appli­ca­tion of the tech­nol­o­gy, it is still only real­ly jus­ti­fied in three very spe­cif­ic cas­es: urgency or the need for a very short lead time; the man­u­fac­ture of very small series or high­ly per­son­alised prod­ucts; or the man­u­fac­ture of objects with a very com­plex design. How­ev­er, these needs are only crit­i­cal in very spe­cif­ic indus­tries such as aero­nau­tics, med­i­cine, space and defence. All of which are, his­tor­i­cal­ly, key sec­tors for 3D printing. 

    Indi­vid­u­als, on the oth­er hand, might feel such needs like avoid­ing the need to go to the shop or wait­ing for a deliv­ery, cre­at­ing cus­tom objects or print­ing parts for repair­ing domes­tic appli­ances. How­ev­er, there is then a pure­ly prac­ti­cal issue: using a 3D print­er is cur­rent­ly any­thing but plug-and-play! You have to dig­i­tal­ly mod­el the object using soft­ware that is still too com­plex, phys­i­cal­ly cal­i­brate the machine before each print, and hope that the print­ing – which can take sev­er­al hours, even for the sim­plest object – will go smoothly. 

    The machines are high­ly sen­si­tive, so tem­per­a­ture, humid­i­ty, vibra­tions or mate­ri­als are all pos­si­ble caus­es of fail­ure2. If it doesn’t work prop­er­ly you will have to start all over again. As for mass cus­tomi­sa­tion, often per­ceived as the flag­ship argu­ment of 3D print­ing, it is cur­rent­ly of lit­tle rel­e­vance, apart from very spe­cif­ic use cas­es like pros­thet­ics. For a long time now, major brands have been offer­ing the pos­si­bil­i­ty of per­son­al­is­ing objects (a pair of Nike shoes, for exam­ple), but few con­sumers actu­al­ly do so. And cus­tomi­sa­tion is nowa­days lim­it­ed to a few objects: what will hap­pen when we can cus­tomise every­thing? Who will take the time to do it?

    So, you don’t think 3D print­ing will take off?

    Not until we find a use that real­ly makes sense in rela­tion to the tech­ni­cal (and not fan­ta­sy) char­ac­ter­is­tics of 3D print­ing. In direct or local man­u­fac­tur­ing, the tech­nol­o­gy is cur­rent­ly only suit­able for very spe­cif­ic sec­tors and under spe­cif­ic con­di­tions. Rare are the cas­es where lead time, small series size, or the need for com­plex­i­ty are impor­tant. In the major­i­ty of cas­es, this argu­ment does not apply for pri­vate indi­vid­u­als – deliv­ery in urban areas some­times takes less time than it takes to print the object! More­over, even in indus­try, the gen­er­al­i­sa­tion of man­u­fac­tur­ing using 3D print­ing is not a giv­en.3

    The fact that the man­u­fac­tur­ing cost per unit remains con­stant is both good and bad news: as soon as the num­ber of units pro­duced is (rel­a­tive­ly) high, the lack of economies of scale becomes par­tic­u­lar­ly lim­it­ing. In this case, it is always more prof­itable to use tra­di­tion­al pro­duc­tion meth­ods. Moulds and tools are made which are cer­tain­ly expen­sive, but they make it pos­si­ble to pro­duce tens or even hun­dreds of thou­sands of units quick­ly at very low unit cost. 

    Addi­tive man­u­fac­tur­ing is not a new tech­nol­o­gy, its found­ing patents were filed in the mid-1980s, only ten years after the cre­ation of the first per­son­al com­put­ers. But ten years ago, per­son­al com­put­ers were already ubiq­ui­tous. Ten years lat­er, wide­spread, acces­si­ble 3D print­ing remains a dis­tant dream, despite all its ‘rev­o­lu­tion­ary’ advan­tages. This shows that it is not the tech­nol­o­gy that makes the ‘dis­rup­tion’, but the use that is made of it. PC sales, for exam­ple, plum­met­ed in the 1980s because peo­ple didn’t know what to do with them… then (paper) print­ers, dig­i­tal cam­eras and espe­cial­ly the Inter­net came along in the 1990s, and every­one cot­toned on to their appeal.

    I think that 3D print­ing will have the same fate. Once cou­pled with data col­lec­tion via con­nect­ed objects, and sub­se­quent pro­cess­ing by arti­fi­cial intel­li­gence, its use­ful­ness will become appar­ent, and will thus cease to be a niche tech­nol­o­gy. It will then be pos­si­ble to print a large num­ber of objects (or more par­tic­u­lar­ly rel­e­vant parts of objects), for which cus­tomi­sa­tion will be fine-tuned and auto­mat­ic, with real added val­ue. But even in this case, it may be enough to have a print­er in a shop near­by. It is prob­a­bly more sci­ence fic­tion that every­one will have a 3D print­er at home one day! After all, decades after their inven­tion, not every­one has a bread mak­er or a yoghurt mak­er at home…

    Inter­view by Juli­ette Parmentier

    1https://​www​.sci​encedi​rect​.com/​s​c​i​e​n​c​e​/​a​r​t​i​c​l​e​/​p​i​i​/​S​0​0​4​0​1​6​2​5​1​5​0​02425
    2Accord­ing to a report by the com­pa­ny Jabil, a lack of skills was in 71% of cas­es what deterred respon­dents from turn­ing to addi­tive man­u­fac­tur­ing rather than tra­di­tion­al pro­duc­tion: https://​www​.jabil​.com/​b​l​o​g​/​3​d​-​p​r​i​n​t​i​n​g​-​t​r​e​n​d​s​-​s​h​o​w​-​p​o​s​i​t​i​v​e​-​o​u​t​l​o​o​k​.html
    3NDR: This may explain why, in 2018, only 4% of French com­pa­nies were using 3D print­ers: https://​www​.insee​.fr/​f​r​/​s​t​a​t​i​s​t​i​q​u​e​s​/​3​8​9​6​4​6​1​?​s​o​m​m​a​i​r​e​=​3​8​56444