Notes on 3D Printing

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Science Fiction

I have just finished reading Peter F Hamilton’s Great North Road. A great SF yarn that involves a detective story set in Newcastle in the 22nd century, interplanetary settlers and a military expedition to a hostile planet. Hamilton’s main draw for me is his anticipation of how we might use technologies already coming into existence today and how that might affect us as human beings. He has wide ranging and convincing predictions about the rise of bio-technology and how we might be using neural and cybernetic implants to enhance ourselves and our abilities in the not too distant future. His vision of where this might lead is the subject of quite another of blog though.

Great North Road has a great play with the future of 3D printing. Hamilton’s interplanetary settlers take 3D printers with them and create whatever they need from a generic substance they call “raw”. As their outposts flourish they can quickly have all that their intergalactic civilisation has to offer without moving goods around the universe. They simply indulge in a bit of filesharing. One of his characters is a surf-board shop owner on a holiday planet. His business is printing the latest gear from files imported from earth. He can also use the printers design and customise boards for customers using his expert knowledge of the sport. The Military in his future universe have even more sophisticated 3D printers. They can create weapons, ammunition, armour and even the buildings for their outpost.

With recent newspaper and magazine articles announcing the arrival of 3D printing in the here and now it seems as though this future is not too far off, or is it?

The last paragraph of the blog. May contain spoilers.

The buzz about 3D printing:

Doctor Wood and IIPSI

Dr Wood himself It was amazing to be able to go to Warwick University to listen to one of the people actively involved in developing this technology: Dr Ben Wood, technology transfer specialist at the IIPSI (International Institute for Product and Service Innovation). He spoke to us proudly waving a titanium drive shaft he and his colleagues had printed for a race car project.

The Coventry Branch of the British Computer Society arranged the talk and the audience was primarily BCS members and fellow technologists.

Dr Wood, whose voice just about lasted for his talk and for a tour of his lab, presented with great energy and good humour. He even gave out prizes for the best questions.

The Doctor explains 3D printing

What we call 3D printing is in fact ALM (Additive Layer Manufacturing). This is a process of laying down material in successive 2D cross-sectioned layers to build up the 3D object.

This results in objects being manufactured in one piece. Objects can be printed complete with moving parts – e.g. ball bearings already in their tracks. It actually opens the door to making things that can be made no other way.

Types of 3D Printing

There are many flavours and Dr Wood talked about the following ALM processes: Powder Bed and Inkjet Head, FDM (Fused Deposition Modelling), MJM (Multi Jet Modelling), LS (Laser Sintering) and LOM (Layered Object Modelling)

Powder Bed and Inkjet Head

We have been seeing lots of coverage on the Internet of powder bed and inkjet head 3d printing as 3D printing. A binding agent is selectively deposited by the heads into the powder to bind it together in layers to build up the object. They can deliver colour at the same time. What you end up with is plaster held together with glue.

The good doctor (I kept thinking he would make a great Doctor Who – he has the appearance and the charisma for it) pointed us at the way the animators for the film ParaNorman used 3D printing to create replacement animation.

Things to note:

  • They were interested in maintaining consistency of the characters’ expressions and their colouring: difficult with clay models in claymation.
  • They had to bath the ‘faces’ in superglue to enhance their toughness.
Dr Wood demonstrated how fragile 3d plaster models are. Plaster and glue is not very strong and the superglue trick does not work if you have moving parts (sticks them together!).

FDM – Fused Deposition Modelling

This uses a strand of polymer from an extrusion nozzle which melts the material and builds up the layers. The nozzle can move in vertical and horizontal directions and turn the extrusion of the material on and off.

We saw a couple of printer models in the lab. There was the expensive one that is fully computerised and basically an oven with a FDM machine built in and a sophisticated computer controlling it. We also saw one built from a kit that can be purchased for about £500. We were warned that although it is affordable it takes quite a bit of adjustment and know-how to get it to work properly.

Another interesting development pointed out is the Doodle Pen. Have a look yourself and see what you think:

MJM (Multi Jet Modelling) also called BPM (Ballistic Particle Manufacturing)

This uses heads to spray out material (much like an inkjet printer) as the heads move back and forth. The droplets cool and harden on impact to form layers of the object. Dr Wood showed us the printer itself and a plastic object he had created with it to demonstrate how the plastic could be set in a range of states from soft and pliable to hard and brittle in the same object. He advised thinking of it as a tactile greyscale range.

LS (Laser Sintering)

This uses a laser to pass through a powder to melt and fuse the powder to build up the object layer by layer from 3D CAD (Computer Aided Design) data. It melts and welds the material together. You can use anything you can turn to powder and melt - from titanium to chocolate apparently.

LOM (Layered Object Modelling)

The consecutive layers are made of paper. They are cut out and printed on their edges in colour and stuck together. You end up with a papier-mâché type model. Apparently they are popular in schools at the moment.

More information came out in Q&A session

How long, how much it will cost and manufacturing times are all dependent on:
  1. Which process you use.
  2. The material you use.
  3. The size of what you want.
Counter intuitively, adding multiples of something in the same run does not significantly drive up the time as long as you can fit that many in the printer. It takes the same number of passes of the head no matter how many objects are on the tray.

The big users of 3D printing

  • Medicine – Warwick University has worked with surgeons to print a replacement pelvis for a patient whose pelvis was badly crushed in an accident. Accurate models of the blood vessels in the brain have been printed for surgeons. Anatomically correct models of hearts and other organs can be printed for teaching purposes.
    It appears to me that combined with stem cell research that the sky is the limit for 3D printing in medicine.
  • Jewellery – precious metals are particularly usable in Laser Sintering machines and allow fantastically shaped pieces to be manufactured.
  • Fashion - some judicious googling around this will reward you with water cooler talking points.
  • Architecture – models that had to be painstakingly built can now be modelled on computer and printed. Extra information such as stress patterns can be represented by how the models are coloured.
  • Electronics – Dr Wood and his colleagues are leading the world in methods to produce printed 3D electronic circuitry. Things like Wi-Fi antennae and RFID can be printed as an integral part of product casing, solving a variety of problems.
  • Automotive – there was a long discussion about this and it appears the future is customised dashboards. However I suspect that the automotive industry’s uses will run to the more practical by prototyping difficult to manufacture parts and rare and expensive parts. They already make extensive use of this technology by well known automotive companies we were told.

Conclusion

From the replicators of Star Trek to the “raw” of Great North Road, 3D printing has been a staple fantasy. It could potentially solve many problems in business and manufacturing. It does not take much imagination to foresee them in each home hooked up to a global Amazon for us to buy eProduct designs in much the same way we now buy or books and music online

This technology is not as advanced as some newspapers and excited reporters claim. On the other hand I suspect it is more advanced than many of us suspected. It is coming. With it will come many obvious benefits but also, in my opinion, social change and ethical dilemmas we will have to face. Every new technology from the printing press to the Internet has excited as much fear, trepidation and criminal possibility as entrepreneurial spirit and creative genius. In the USA the possibility of people uploading workable firearm printing blueprints has been raised along with the question of how to deal with the ensuing proliferation of untraceable undetectable weapons. Last night one questioner light heartedly raised the spectre of impending AI running these printers to clone themselves and take over.

Dr Wood, who has been living with the reality and the bugs in this technology, did not see Doomsday as imminent; but there was a nervous laugh nonetheless. We have all uploaded the film Terminator into our own personal 3D nightmare printing apparatus.

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