3D TECHNOLOGIES    3D PRINTING OVERVIEW   3D printing, also known as additive manufacturing, is a method for fabricating a physical object from a digital model, building up layer upon layer of material to gradually build an object. Whereas traditional subtractive manufacturing methods cut away material from a solid piece, e.g. wood carving or metal machining. Or perhaps use moulds or stamps to form an object from a hand crafted design. Modelling In 3D     A 3D printable digital model may be created with a Computer Aided Design (CAD) program or via a 3D scanner - where a laser is used to collect digital data on the shape of a real object. Lithophane digital models can be created from ordinary image files using web tools. Thousands of ready to print model files can be downloaded from the internet. There's a wide range of CAD package features and prices - from free to many thousands. FreeCAD (www.freecadweb.org) is unsurprisingly free, TurboCAD Deluxe(www.turbocad.com) is popular at around £100 and comes with tutorials, Rhinoceros Rhino 5 3D (www.rhino3d.com) weighs in around £1,000 and has just about everything covered. We have purchased five versions of TurboCAD (2015, 21 Pro, 21, 20 & 14 Deluxe - the version we prefer), each has had the options for creating simple 3D shapes and performing Boolean operations to add or subtract - a bit like creating your own Lego blocks to build something. Among several new 3D scanners for home use, Matter & Form (matterandform.net) have the most accurate device for under £500 - this is the type we have and here's a video of another one in action: www.youtube.com/watch?v=2JZ5kTU2_5c The same company offers a smart-phone accessory for under £100 called the Bevel, which when it works currently only really allows you to take a 3D-selfy in the form of something like a death-mask, but is still being developed and may in future be able to do more useful scanning.   Using TurboCAD to 3D draw. A Lithophane is an early 3D art form said to have been created by Baron Paul de Bourging in the 1820s, where a picture will be revealed in the light shining through an engraved translucent panel. You can create 3D printable files from your own photographs, for free on your PC in seconds, with a brilliant web-based app that works entirely in your Google Chrome, Firefox, or Internet Explorer 10+ browser with open-source JavaScript. Any image file might be used to create a complex 3D design making use of the tone to depth conversion technique - printing stamps, or in reverse moulds, textured surfaces, etc.: 3dp.rocks/lithophane The most common 3D printing ready output from 3D tools is currently a Standard Tessellation Language ".STL" file, also known as a "Mesh". Web sites such as Thingiverse (www.thingiverse.com) offer prepared design files for all sorts of objects: movie theme ornaments, chess pieces, useful gadgets, the list is litteraly endless. "3DS" from AutoDesk 3D Studio products is an older commonly supported file format amongst most 3D drawing programs, but it has a limit on complexity. There are special programs to convert other file formats into ".STL" and we can convert early TurboCad ".TCW" native format files if required. Microsoft, HP, Shapeways, Autodesk, Dassault Systems, netfabb and SLM Solutions have founded a new "3MF Consortium" which will be developing the proprietary ".3MF" file format to use with a planned range of new 3D developments. They claim that new features, such as multiple colours, will be better supported from design through to printing, as no doubt will their profit margins from that kind of integration. XYZ-Printing have a ".3W" format which bundles printing information such as supports and placement specific to their range of printers from their printer driver software. Formlabs uses a "FORM" file format for its print files generated by their "PreFORM" software. 3D Printing Machines A large number of different printing processes are now available for modellers, which in the last few years have become increasingly affordable. Technologies have come and gone, most have evolved and new ones are being developed all the time. The main differences between them are in the way layers are deposited to create the objects, and in the materials that are used. It's a subject littered with acronyms. There are some very obscure technologies like Laminated Object Manufacturing (LOM) where thin layers are cut to shape and glued together, forming shapes from paper, polymer or metal. There are machines that inkjet print paper layers after cutting them out, before automatically joining them together to produce a multi-colour 3D object. It's common that inkjet colour printing inks fade over time. The inititally most popular methods of 3D printing in the service industry were machines that melted materials to produce the layers. For example Selective Laser Melting (SLM), Laser Powder Forming (LPF), Direct Metal Laser Sintering (DMLS), Electron Beam Melting (EBM) or Selective Laser Sintering (SLS) - used typically today with white nylon powder in industrial-scale machines that can form very strong large objects within supporting material that can be quite an effort to manually clean away after printing. There's one new reasonably small machine announced by Formlabs using nylon powder called the Fuse-1 which is in the £20k bracket. The finish is always powdery looking to some degree, but it's really tough. The most popular machines with home-users employ Fused Deposition Modelling (FDM) or Fused Filament Fabrications (FFF), where often coloured thermoplastic filament is extruded from a high temperature nozzle which then hardens to form the layers. With these devices the build is performed from the base and rises up, and is even available in hand-held pens for 3D doodling, with most printers costing under £500. XYZ-Printing are the market leaders in this type of machine, which as well as some having a basic built-in 3D scanner, can also offer a Laser Engraving feature by way of a replacement module for the extruder head. This technology for 3D printing always has clearly visible layers which are very hard to sand-down. In the middle of the technology price range is what we opted for, StereoLithogrAphy (SL or SLA). Invented in 1986 as a method for printing using an ultraviolet light curable liquid polymer, where a UV light forms the object slice by slice at the bottom of a vat of usually room-temperature liquid and photopolymerization creates the solid in the resin, which is usually raised out by an elevating build platform. There are increasing variations on how such machines operate: some scan a laser point beam by reflecting it from moving mirrors, mirror-galvanometers as they are known, others employ full-layer exposure using a Digital Light Processing (DLP) or projector device, containing a chip which is a Digital Micromirror Device (DMD) or Liquid Crystal Display (LCD) array. Solidification can occur directly against a non-stick tank base, or at a layer away from the base controlled by oxygenation, and there are some top-down units that work upside-down to the norm. The different methods determine the resolution, speed and build volume. The best selling and best rated printers up to 2020 have been made by Formlabs, the typical cost is around £4,000 for all of the equipment to get started with any particular resin based technology.   Our first set up for making Precision 3D Models. At the high end there are large scale and faster machines based around inkjet-like spraying, such as Jetted Photopolymer (J-P), Drop On Demand (DOP), Colour Jet Printing (CJP) also known as Three Dimensional Printing (3DP), and MultiJet Modelling (MJM) or MultiJet Fusion (MJF). Major companies Samsung, HP and others such as Japan’s Mimaki Engineering are all building on their expertise with 2D inkjets to create new multi-colour resin spraying machines for the future. Because of their cost, it's likely these machines will always be restricted to large printing services companies like Shapeways - who are investing in these spraying technology developments. With the exception of opaque black and maybe white, self-coloured plastic is not generally as desireable for modellers as paint-finished models which look more realistic. 2020 saw interesting developments with a type of 3D printing called Volumetric Additive Manufacturing (VAM). Previous variants of VAM included two-photon photopolymerization (TPP) and computed axial lithography (CAL). In TPP, slow 10-15 seconds laser pulses are used to polymerize a medium. In CAL, images are projected at different angles around a rotating volume, controlling the cumulative light exposure at different Voxels (3D pixels), in concert with the use of dissolved oxygen to prevent unwanted polymerization. With the latest Xolography variation, solidifying chemical reactions are triggered by the intersection of two light beams of different wavelengths. A rectangular sheet of light with a set thickness is shone through a volume of a viscous resin, the particular light wavelength excites molecules known as dual-colour photoinitiators (DCPIs) that are dissolved in the resin. A second beam of light via a DLP then projects the image of a slice of the object to be printed into the plane of the light sheet, and that causes the activated DCPIs to polymerize, solidifying the resin only where the two wavelengths of light have crossed. The resin volume is then moved for the process to occur at new locations in the resin. There are no slow mechanics to draw an object out from the starting material, but costly computer optimization using a feedback system is required. The process avoids the need to print support structures for the object that would need to be removed after printing. Currently, the major limitation is the rather small volume that can be printed, restricted by the few centimeters that light beams can penetrate into the resin. Xolo has announced the first purchasable volumetric 3D printer, the Xube, aimed at developers and academic researchers. It's small, 50x50x50cm with a build volume of 50x70x90mm, with an optical resolution of 0.03mm on the X-Y axes and 0.05mm on the Z axis, the typical print time is described as less than 5 minutes! New inventions and developments happen all the time in this fast moving field. In recent years it's most often involved variations on the SLA with DLP theme, all working around 25 micron Z layers. Anything stated as 25 micron or finer Z layers is often hard in practice to differentiate from prints done around 50 micron. There are some really fast but very expensive machines from Carbon3D using Continuous Liquid Interface Production (CLIP) with what's been called the "Terminator Printer", there's a large build-platform Morpheus printer using Light Induced Planar Solidification (LIPS), and from Holland Atum3D are now claiming a 6 micron resolution industrial grade machine around €13,000. Current DLP-based printers can work fast once they get going, but they are controlled by their fixed pixels which at best have been around three times more coarse resolution than the best movement control of laser-tracing SLA systems. However laser-tracing SLA systems cannot print features smaller than their laser-spot size, typically an order of magnitude greater than the finest pixels of DLP-based systems. With larger build volumes the DLP X-Y resolution often gets reduced as everything is stretched from a fixed pixel array, and distortions can occur because of edge focusing issues, making them look the sharpest only with very small prints. There may be counter-intutive results, for example affecting optical clarity on clear resin prints where higher stated resolution models of the same printer type can give surprisingly worse results. We tested the Formlabs Form-2 versus their Form-1 and Form-1+ and the supposedly better of those printers was not actually able to print as smooth and clear a surface on the same test, however the latest Form-3 printing is clearly the best from Formlabs and quite glass-like before any treatments. A Form-3 costs around £3,500, and the larger platform Form-3L around £10,000 - these use the "Low Force Stereolithography" (LFS) variation on peel action, which allows for generaly smaller "light touch" supports that are easier to remove after printing, perhaps just by pulling a part away from them. One place to get more news on how things are evolving is the 3DPrint web site. At the start of 2015 they produced a summary of the best home-use 3D printers, then in the middle of the year a scanner guide - that rating our scanner as the best: 3dprint.com/55890/buy-3d-printer-cheap/ 3dprint.com/81886/2015-3d-scanner-buyers-guide/ The ALL3DP web site reviewed the best SLA printers available for 2016 - our printers being noted as the best selling and described as setting the standard - and in subsequent reviews noting has changed: all3dp.com/best-sla-3d-printers/ 3D Manufacturing Considerations     If you invest in any of the 3D technologies yourself, you'll need to have a significant amount of stuff to print. Offering a printing service to other model designers can help to keep a printer in good order and get some use out of it while it lasts, before it undoubtedly becomes prematurely obsolete. People can offer their printing services through a website: 3dhubs.com. The regular use of a 3D printing machine is highly recommended to avoid costly clogging blockages or other break downs, and will reduce the overheads of all the maintenance and cleaning they require. Filament machines should be cleaned after a certain number of hours in use and may require extruder replacement. We have discovered to our cost that liquid resin chemicals can have a shelf-life which means you may need to use them up within a year or two from manufacture. Where resin tanks are silicon as opposed to Teflon coated they will wear out with UV burn, and we've had plastic tanks leak we think as a result of being attacked by the resin chemicals after only a few months in use. Supplies might only be made available for a few years from the launch of a printer, forcing high on-going upgrade costs when you are unable to get supported consumables - we've found that with certain US firms in particular. Fortunately there's a growing after-market of companies offering better consumables like ZVatIndustries for the Formlabs machines with longer-life glass tanks and Fun2Do with compatible resins for lots of printers.   Thingiverse downloads, Formlabs Form-2 Printed. We have considered numerous SLA type machines for our manufacturing requirements, and we continue to review devices in development to update this page. We started printing with a Form-1 printer and had lots of issues with multiple breaking tanks, a dust scattering laser, and hundreds of pounds worth of resins seemingly going off. We sold that and upgraded to the improved Form-1+ model, but that broke down in a similarly unreliable way within only a few prints - it was repaired with nearly all major parts being replaced and worked perfectly for only about 1.5Litres of printing before another similar failure and repair - we are now keeping that as an unopenned spare, and have bought three other Form-1+ printers to use. It seems that printing with the opaque resins on the Form-1+ is not a good idea if you want the laser to last. The Formlabs Form-1 and Form-1+ can easily work with cheaper third party bottles of resin - the resins just need to be compatible with a Formlabs resin setting in PreForm, or there's an "open" version of the driving software and firmware that allows all sorts of experimentation with exposures for example. As well as withdrawing several resin options for their early printers, Formlabs are now refusing to service repair their 1 and 1+ machines, so when (definitely a when not an if in our experience) they break that's it! We also obtained a Form-2 which gives some of our best prints, thanks to its unique peeling and wiping mechanism with slighly smaller laser spot size, the notably sharper printing requires some specific part orientations and support structures. Predicatably though our Form-2 broke down, three times in all, before Formlabs very kindly sent us a new replacement machine! The Formlabs Form-2 isn't as optically "sealed" as advertised, it's more covered than their other models with shrouded internal optics, but dust can still enter. If you're brave and careful Formlabs do offer advice and special wipes to attempt internal cleaning operations, but in our experience you're on a rocky road to a big repair bill. The printers use OEM chipped resin cartridges, although there is an "open mode" for the printer to handle 3rd party resins which is then done in different ways. It's worth noting that the "long life" tank option will probably not have as long a life as the normal tanks because resin can get under the edges of the coating more easily over time and its not as durable and can tear easily if you have to remove stuck-on debris. The latest Form-3 and Form-3L benefit from the unique peeling action that they call LFS and a new variation on the X-movement of now completely sealed laser Light Processing Units (LPU). There should be a big improvement on issues with dust, and a bit easier post-printing processing where smaller and fewer support touch points are required. They both use the same OEM chipped resin cartridges, and for the Form-3 the same build platforms as the Form-2. Again a smaller laser spot size, now with spatial filtering and linear projection, but actually slightly worse X-Y motion control specs. The new tank design, which starts off frosted looking, is said not to be so affected by laser burn and is said to last for up to 600 hours of printing or 250 days exposed to resin, whichever happens first - that might cover 5 litres of printing versus the recommended 2 litres per tank with the other printer models. The new resin heating method involving a fan leads to a big increase in resin odour in the room while printing. The Form-1, Form-1+, Form-3 and Form-3L printers are the best for printing "wires", like say model telegraph poles vertically, and thin "unsupported walls" are especially good on the latest printers - such prints are easier, quicker and cheaper than the Form-2 because of the different support requirements of their specific peeling actions. However the Form-1, Form-1+, Form-3 and presumably Form-3L can suffer from some surface fidelity issues, where random ripples appear, said to be due to movement of the model on the platform during printing - more supports and thicker printing layers are recommended to prevent such problems. A firmware fix is said to be coming for these issues with the latest Form-3 printer, until then the "best" 25 micron layer setting is to be avoided! Despite the quibbles, the print fidelity resulting from the Form-3 low force action can be amazing on fine thin parts and edges with the Opaque Black resin, while the special peeling process certainly delivers the best optical clarity with Standard Clear resin - it is an industry leading printer. At the moment, the Form-3's best surface results seem to be obtained with Standard Clear resin printing on the 50micron setting, but there is some expansion or spreading of fine details like pipes with that combination, it's also more brittle on small details than with other resins. The Form-2 with Opaque White, which will only go down to 50micron layers even on the Form-3, produces beautifully sharp prints that we note do not warp when thin surfaces are left in the sun - something that can affect Opaque Black prints from the Form-3, although after the promised firmware fixes we hope that will improve. With Flexible Black resin rather large support touch points are required, with the Form-3 the default is 1.5mm, while the Form-2 defaults to a whopping 2.2mm. Durable Frosted resin is another one requiring larger supports, but only slightly larger with 0.7mm as the default on both Form-3 and Form-2. The Form-1+ still produces nice quick prints with great surfaces, especially with Translucent Grey resin, just not as detailed because of the lower resolution - a bit like a soft-focus picture. There have been a number of other DLP based SLA printers which interested us. There was one that looked good from stalactite3d.com - but we were not able to make contact with that short-lived pop-up. A similar but far too small build platform unit with a separate not-included DLP projector comes from www.reify-3d.com, the Solus, it has a website with no options for ordering spares it seems. There's a couple of Chinese budget DLP printers under £500 that look very similar: one from Anycubic called the Photon which has USB flash drive support, 155x115x65mm; another from Wanhao in China the Duplicator 7 V1.5 which works as a PC screen, 200x120x68mm; both state upto 25 micron Z with 47 micron X-Y resolution. Reviews note several issues people have had, difficulties with consumables which are said to be smelly even toxic, and cannot be left in the printer for very long. One to watch out for home-users we think is the "open source" Pluto from www.3devised.com, a unique top-down printing design which eliminates several difficulties other printer designs have and is said to be able to handle almost any resin. In the 2016 Black Friday sales we couldn't resist a bargain XYZ-Printing DaVinci 1.0 Junior FFF type printer - the first thing we printed with it being an upgrade "wind duct" part to improve fast printing - clever concept that, a self-upgrading machine. The driving software is rather limited and the quality of printing looks like miniature basket-weaving, but it's so cheap and easy! We have used it to print custom postage containers with supporting structures to safely post our other more delicate 3D printing in. Things are around one tenth of the cost to print compared with our other printers and it will save on postage costs by allowing thinner wrapping. The support that you might get from a device manufacturer's customer services we've found can vary enormously - we've had some excellent support in the past from Matter & Form and repair agents for Formlabs ExpressGroup/GoPrint3D, the former offering no quibbles speedy replacement of broken units the later excellent advice and customer service. Formlabs themselves though have had an unfortunate habit of making products "end of life" and ceasing to offer adequate support on equipment after a comparatively short period of time for such expensive purchases - contravening EU guidelines on supply of consumables and parts. Annoyingly while getting ready for the Form-3, they removed support for the Form-1/1+ printers from their PreForm software latest releases - by setting a different install directory you can install different versions of the program. The software that controls a particular device is usually propietary and tied to a particular brand of machine - some work with just a few clicks to scan or send a design file to print, others are highly technical and customisable for use with third-party consumables and may involve applying parameter charts and tables of conversion factors. Hardware may also require extensive set up and calibration, which could be difficult and time consuming, often a feature of DLP based kit-like machines. As a result there are wide variations in features and ease of use. The easiest machine to operate is probably the Form-1+. One of the highest resolution printers, capable of printing a free-standing 45micron needle, the Kudo3D Titan, is at the other extreme of complexity to operate, as you can see in this 92 minute video: www.youtu.be/i8GWZSHCxEw Here's a couple of time-lapse videos of the printer we started with, showing the relatively easy process of printing using design files downloaded from library sites: www.youtube.com/watch?v=enJq2PquuPE www.youtube.com/watch?v=jyWbAdkwwIY For the time being, we believe the best and esiest to operate options for our precise printing requirements are still the Formlabs printers, despite all the costly and repeated problems we've had, and that's why we bought two Form-3 printers! There are some optional accessories from Formlabs in the form of Form-Wash and Form-Cure units to automate the print cleaning and curing, for those too lazy or busy to shake a plastic tub full of IPA and who've not seen UV nail curing or towel sterilizer units costing a tenth of the price - they just need to generate 405nm UV to cure Formlabs "standard" resins - we are told some heat baking is also necessary for the "functional" resins to achieve their full stated special mechanical properties. There seems to be an increasing focus on the needs of Dental practices and Jewelery makers with more and more specialised resins being released. Formlabs have hinted at new types of resin to be released to work with the Form-3.