3D Printers lack closed loop control

One of the main technical hurdle the current 3D printing technologies need to take is to go from open loop to closed loop control systems. Closed loop control will enable higher resolution and faster printing.

So what is closed versus open loop control? In an open loop control system machines get their instructions and start working. Components of the machine work within a set of parameters. There is no check if the components actually function as expected. It is assumed that they do. Regular calibration of these components insures that the machine keeps on functioning properly. Every mechanical component has variances during operation due to wear-and-tear or environmental conditions. During the design phase, components are selected which can keep on operating inside a specific range of operating parameters. Calibration during installation and maintenance cycles make sure they keep within that range.

Closed loop systems check themselves during operation to see if they are working correctly. If not, the machine calibrates itself while operating. In case the machine cannot correct the problem, it goes into error mode. Due to closed loop control machines are more reliable, and it allows machine manufacturers to push the components to their limits where variances in operation are greater but are self-corrected. In practice, this means better performance — both in speed, reliability and accuracy.

For a more in-depth explanation, please read the article Open And Closed Loop Control in CNC systems.

The current generation of 3D printers does not have or only extremely limited closed loop control systems. Wipers, laser mirror systems, printheads, material feeders and build platforms are operating nowhere near their capabilities. The only significant closed loop control system I am aware of is temperature control in the build chamber in various machines.

An excellent visible example where closed loop control systems made a significant impact are car engines. Up until 1980s car engines were mostly open loop systems and they tended to break down often. At the end of the 1980s, car manufacturers started to introduce closed loop systems in cars. The result was far more reliable engines while increasing performance and fuel efficiency.

Another reason to closed loop control systems to 3D printers is the option to extend the current material portfolio. 3D printing processes are very much married to their specifically designed materials because of this. For any new material, it is looking for a needle in the haystack to get the material properties perfectly aligned with the machine capabilities. It takes a considerable effort to make sure the material properties are kept stable during production of that material.

Closed loop control systems will make a significant impact on 3D printing technology in terms of speed, reliability and accuracy.

Blank Canvas Syndrome and Co-Creation

Give people blank piece of paper and ask them to draw something. A lot of people will hesitate and wonder what to draw. In my previous post, I talked about what you could do with a 3D printer at home. In this post I argued that most people are not 3D designers or aspire to be one. One of the reasons is that they simply have no idea what to make.

Blank canvas syndrome (BCS) is similar to what blank page syndrome is for writers — also called writer’s block. You do not know where to start. You have the tools or skills but there is no idea, no creativity. If you ask people what they would like to draw with 3D drawing software they have no idea. The blank canvas is staring in their face.

BCS is actually a problem for unleashing the creativity of people. There is a need to create and express yourself but the what is lacking. Designers — obviously — do not have that problem and there lies also the key. Co-creation or co-design brings designers and consumers together and let them work together on a design. When asked about what people would like to change on an existing product they have clear ideas and wishes. Together with a designer they can make wishes come true. It is how interior designers like to work.
Another solution is to give template-based designs and thus avoiding the blank canvas. Allow consumers to modify a template using a limited set of modifiers. This is basically what the design-your-own T-shirt and canvas companies offer. It made Zazzle and Cafe Press big.

In a next post I will go more deeply into design exploration and how it can help people to realize their ideas.

3D printing technologies explained

In this post, I would like to give an overview of the 3D printing technologies which exist today. Each of these technologies deserves a blog post on its own, but I want to start with an overview.

While writing this    blog post, I realized that I needed to introduce some concepts first before I go on explaining the specifics of each of the technologies:

  • Build platform — platform on which the parts are build. Just imagine a plate which can be lowered and raised.
  • Build chamber — chamber in where the 3D printing takes place. It consists of the build platform, heads / laser or projectors, the material distribution and depositing mechanisms.
  • Layers — 3D printers build parts in layers which are stacked on top of each other. In most cases, you can recognize the layering when examining a 3D printed part.
  • Support structures — structures to help the printing process. The structures support overhangs while printing making sure the part does not collapse on itself during printing.
  • Support material — special material for making support structures. The reasons to use a different material is that it is easier to remove and recognize during cleaning of the part.

SLA — Stereolithography Aparatus
This is the oldest commercial 3D printing technology invented by Chuck Hull in 1984 and commercialized by founding 3D systems in 1986. The printing works by having laser solidifying a liquid resin in a VAT on a build platform. The next layer is added by lowering the build platform inside the VAT. After printing, the part is cleaned in a chemical bath, and cured in an UV oven. This technology needs support structures.
A variation of this technology uses DLP (Digital Light Processors) instead of a laser to cure the resin. This makes the printing process go faster.
SLA systems are manufactured by 3D SystemsEnvisiontec (DLP) and ZCorp(DLP)
For more information see this excellent Wikpedia article.

SLS — Selective Laser Sintering
This technology was invented by Dr. Carl Deckard around the same time as SLA. The process is essentially fusing small particles in powder form together using a laser. Just below the powder this is a build platform which lowers to make room for the next layer. A wiper redistributes the powder over the platform, and the next layer is fused by the laser. This technology does need support material or structures. The powder functions as a support.
Using SLS several types of plastic, metal and ceramic/sand powders can be used.
SLS systems are sold by EOS and 3D Systems.
For more information see this Wikipedia article,

FDM — Fused Deposition modeling
Scott Crump invented FDM in the late 80s and commercialized it through his company Stratasys in 1990. FDM printing works by extruding a material through a nozzle and move the nozzle over a build platform to “write” the part. The next layer is added by lowering the build platform. Support structures or materials are necessary for this technology, but not all manufacturers offer that option and thus limiting the usefulness of their FDM systems.
Common materials are plastics, but other compound materials are used as well. FDM technology is employed by many low cost hobbyist printers.
FDM systems are sold by StratasysMakerbotUP![email protected] and others.
For more information see Wikipedia

3DP — Three Dimensional Printing
This technology came out of MIT and was invented in 1993. It is commercialized by Z Corporation, but others use the same technology, as well. 3DP uses a powder as well in the printing process. The powder is “glued” together by binder on a build platform. The binder is deposited by a moving head. The next layer is added by lowering the build platform. A wiper redistributes the powder. The powder acts as support, so this technology does not need any support structures or material. The parts are extremely fragile after printing and need to be carefully cleaned and cured.
There is a wide range of options for powder and ranges from plaster, ceramics, metals to glass. Unique to the commercial application of Z Corporation is the ability to color the parts during printing resulting in parts delivered in full color.
3DP systems are manufactured by Z CorporationExOne and Voxeljet.
For more information please see the 3DP page at MIT.

Polyjet matrix printing
This technology is specific for Objet Geometries. The process builds parts by extruding or jets extremely small droplets of material onto a build platform. The head can drop multiple droplets at the same time — hence the name matrix. After depositing, the material is cured using UV light. The next layer is deposited on top of the previous layer. This technology uses support material during building.
The material used in this process is a polymer. Unique to this process is that it can use two distinct materials to build a part including mixing these two materials in different variations.
Polyjet matrix systems are manufactured by Objet.
For more information see Wikipedia.

EBM — Electronic Beam Melting
This printing process is developed by Arcam which was founded in 1997. This process uses a powder which is fused together on a build platform by an electronic beam. By lowering the build platform and redistributing the powder using a wiper, the next layer can be build. The process is similar to SLS but uses an electronic beam instead of a laser.
The powders are always metals with different types of alloys. The build chamber is a vacuum and heats up until 700–1000C.
EBM systems are manufactured by Arcam
For more information see the EBM Wikipedia page

LOM — Laminated Object Manufacturing
This technology is developed by Helisys. it uses thin sheets of material which is cut by either a laser or a knife according to the outline of the part. Next the sheet is glued on top of the previous cut sheet of material. After printing the excess material is “broken” off and you are left with the printed parts.
LOM printers mostly use paper, but there are also other materials — mostly various plastics.
LOM systems are today only manufactured by Mcor technologies.
For more information see this — somewhat sparse — Wikipedia article.

These are the most 3D printing technologies manufactured today. There are more technologies and variations available in both research and production, but they focus on real niche areas.

Why would you want a 3D printer at home?

In my second post about the future of 3D printing I ended with this question. It is a valid question to ask I think. Most technologies start out as very specialized and very expensive niche products and become mainstream after a decade or so. Computers, air conditioning and microwaves all started out as business technologies and are now standard household equipment.

First of all it is about content. The digitization of product design helps to bring content in the digital domain. Just take a look at the website of Shapeways (disclosure: I work there) or Thingiverse and you can see that there is a tremendous amount of content available already. The availability of content is accelerating. But here we are talking about unique designs. Just imagine when spare parts or add ons become available as downloadable and printable content. You buy a standard off-the-shelf product but need a small customization to fit your own needs. Just imagine a standard light switch for your home and custom cover. Or maybe the cover you want is out of production and you make your own based on the original design.
Or you break the battery cover of your remote control. You download a replacement from the manufacturer’s website and a little bit later you have your brand new battery cover in your hand.

Secondly it is about availability. 3D printing is instantaneous albeit the machines are currently still slow. No need to wait for UPS or Fedex. Just push the button and the product becomes materialized before your eyes.

And third it is about cost. To actually produce something in China based on a design created in the USA and ship it over to the distributor who brings it the shop owner’s warehouse who ships it to one of his stores is expensive. Next to that shop owners have more costs like their store rent and personnel cost. For this reason a $2 product is sold $40 at your local store.

Most people are not 3D designers or aspire to be one. There will be a great revival of making your own stuff. And that is already happening. Just take a look at one of the Maker Faires and you see what I mean. But I do see a lot of need customize and personalize products to your own requirements. Think about changes in size or color but also in form and function. But to actually design your own products is quite some work. And then you always have this nagging feeling if it is fit for purpose. That is actually something more for hobbyists and professionals who would like to put in the time and love in designing products.

3D printing at home is already a reality using printers like Makerbot or Up. They are even quite affordable but their usage it is still very limited because the limited abilities of the printers and the low quality of the prints. They are hobbyist printers. Of course we need to start somewhere. These printers are definitely not ready for mass adoption yet. The same applies for content which is not there yet either. Companies need to adapt and rethink their business models. Lucky for them they have another decade or two.

Future of 3D printing — part 3

In my previous posts on the future of 3D printing I talked about the impact on manufacturing and development of the industry. In this post I am going to talk about the next steps of 3D printing as a technology.

Digital materials
I want to talk about digital materials first. This technology is researched by Hod Lipson from Cornell University. The theory is to assemble parts by stacking extremely small grains of materials and cure them. It is inspired by how biology creates complex structures like DNA or proteins.

Each grain is put on a grid next to another grain based on a digital model. It allows for mixing materials by selecting the appropriate grains from a bucket. This allows for a large variety of materials to be used to build the part something currently technologies cannot do. But it becomes extra interesting when grains of different materials are mixed in a specific pattern. It allows for the creation of completely new materials with very unique properties which do not exist today.

Another reason why I am bullish on this technology is that it is very digital instead of the current 3D technologies which are more analog. Going from digital to digital gives much more control on the output, allows for more manipulation of the 3D models and is easier to automate reliably. Just look at television which went from completely analog to fully digital today. But the same applies for music players (MP3 players) or computer storage (SSD).
Please also read the excellent web page about digital materials at Cornell

Voxelization of 3D models
The other major step I see is the voxelization of 3D models. It is actually related to digital materials. Hod actually calls the grains voxel but I refrained from using that term in that part of post to avoid any confusion.

With voxelization of input I mean that the input is changed from polygons to voxels. 3D models today are mostly described in files using polygons. These polygons describe the contour or shape of the 3D model in a similar way vectors describe drawings. The benefits for describing 3D models are that the current computer technology can easily handle them. The required file size and memory in a computer is small in comparison to voxels. The problem is with resolution. Polygons are only an approximation of the contour of a shape. Very high details require huge amounts of polygons and are still only an approximation of the actual desired shape. It does not describe how a 3D model actually is build since it is only focus on contours or shapes. When multiple material printing becomes more prevalent it becomes cumbersome to keep on using polygon based files.

The solution is to use voxels. Voxels are 3D pixels and can be compared to pixels of a photograph — but then with 3 coordinates instead of 2. The 3D model is described as discrete blocks. Using that model it is possible to create much more complex 3D models than with polygons and it enables designers to actually specify how a 3D model is build physically.

Another benefit of voxel-based 3D models is that they are easier to reliably manipulate and process by computer software. You can compare it to processing of photos using Photoshop.
The problem with voxels is that they require 100x to 1000x times more data to describe a model. With current computer technology this is not very practical. Luckily Moore’s law comes to the rescue — which states computing power will double every 18 months.

To me both digital materials and voxelization of input will lead to major breakthroughs in 3D printing. Both technologies are still very much in research. Voxelized 3D models are using in some very very high end applications like MRI scanners. It is in my mind also closer to reality than digital materials.

Future of 3D printing — part 2

In my previous post about Future of 3D printing I wrote about the bigger effects of 3D printing on manufacturing. In this post I would like to go into the revolution of 3D printing itself as a technology.

3D printing is a reality since 1986. Most people who hear about 3D printing today are amazed that the technology is this old. Of course the technology has improved over the years and 3D printers of today are very much different than those of the past.

In the last two decades the 3D printing technology have diversified in different directions. Each technology has its specific use cases. Still the total market is tiny if you look at the potential. I define the total market as the combined manufacturing sectors.

Although nobody can look in the future my take is that 3D printing revolution is already starting. The analogy with the computing world is striking. In the seventies there were essentially two computing platforms; mainframes and hobby computers. It took until the beginning of the 80s when the personal computer came to the world which made the computer a household item.

3D printing is currently in the seventies where there again two platforms; high-end industrial 3D printers and relatively cheap hobby printers. If I extend the analogy it will take another decade before everybody has a 3D printer in its home.

3D printers are also disruptive in another sense and that is digitization of manufacturing. Of course a lot of manufacturing is has been digitized already — at least in the sense of CAM. But 3D printing goes direct from design to manufacturing. It is as simple as clicking 3D print in your favorite 3D software package. No special manufacturing or equipment expertise is necessary. I know I am over simplifying but it is not far from reality today.
The effect of this that the role of factories and the way manufacturing is going to change. This change has a very important effect because it actually allows much more freedom in where and how products are produced. 3D printers are more or less standardized equipment and when you have created your 3D representation of your product you can print it in your office or mass-produce it in your factory. It is essentially the same thing. You can even change manufacturing locations based on demand. It will create a huge archive of 3D models which can be produced today, but also tomorrow, or in a decade from now. Just imagine the potential when you can just as easily produce a Ferrari of today as a T-Ford from 1908 because the digitized design is available.

So the question is what will you print when you have a 3D printer at home?

Future of 3D printing

3D printing has all the signs of being a genuine disruptive technology. 30.000 feet high there are four major areas where I see 3D printing has impact:

  1. Personalized products and personal fabrication
  2. Reduction design-to-manufacturing cycle
  3. Bring back manufacturing to the Western world
  4. Manufacture parts which were not possible before

Personalized products and personal fabrication
3D printing makes it possible to do one-off unique parts production. Because of this it is possible to personalize products based on taste or function (think clothes). Embedded in this is also the option to make your own things. Just think hobbyist who want to create stuff for their hobby like model train models which are not sold by any of the major manufacturers.

Reduction design-to-manufacturing cycle
Mass produced products contain mass produced parts. These parts are produced in very high volume to make them cheap. To change the design of such products takes at least the cycle to retrofit existing production lines. The time to do this can take weeks to months.
Using 3D printing it is possible to make immediate changes and put them in production. The cycle is then reduced to left-over stock but could be brought down to days.

Bring back manufacturing back to the Western world
Manufacturing has mostly migrated away to low-income countries. Since 3D printing is a mostly automated production process there is no need for low income machine workers to make the production cost efficient.

Manufacture parts which were not possible before
3D printing allows for manufacturing parts which were not possible before. The most practical application I have seen up until now are ceramic filters and special molds for iron/steel casting processes. I think this area is currently very much under valued because a lot of engineers / designers are not ware of the capabilities yet.

Nokia Microsoft marriage is the end of Nokia’s handheld business

Nokia and Microsoft announced a partnership today. Together they will form a smartphone alliance. The high end profitable market of Nokia smart phones is moving to the Windows mobile platform. Nokia will move the Symbian platform which they used exclusively up until now to power the mid and low range models.

The effect of this decision is very profound for Nokia and Microsoft. For Microsoft it finally opens up the market for smart phones for them. Nokia’s market share is still very sizable. For Nokia on the other hand it will move them into a hardware maker. The implementation of Windows mobile will lead to margin erosion on their handheld business. Even if they manage to be a huge player in the smartphone market and become successful with bring Windows mobile handsets to the market they will lose anyway.

There is no exclusivity in the Windows mobile platform. When it Is successful other handset players will enter into this market too. The added value Nokia will bring is limited to the quality of their hardware. Any add on service or software they bring will be copies any of the other handheld makers or Microsoft themselves.

The only company who wins in this marriage is Microsoft. Nokia has nothing to gain from this deal and can only loose. Either the platform is not successful and they will lose even more market share. Or the platform is successful and other companies will jump in and erode the market for Nokia.

The future for Nokia is now very bleak. Most likely it will end the Nokia handset business in a few years — possibly 5 years from now. Nokia will sell its handheld business to a competitor who is interested in the hardware technology Nokia created. Most likely an Asian company will take over and use it to jumpstart their handheld business or bring it to a higher level.

It is decisions like this which makes you wonder what the board of Nokia was thinking at the time when they brought in Elop. I am sure they are scratching their head right now since Nokia’s shares went down from $12 to $9 in 2 days.

Why AI is hard

Artificial intelligence was one of the first buzzwords I can remember from the previous century. It promised a future with intelligent computers or devices which could understand you and act autonomously.

Up until now we still do not use AI-enabled devices in our daily life. Why is that?

Our brain has 10 billion brain cells. Each brain cell has 10.000 connections to other brain cells. Neurons activate pathways to brain cells. The activation of brain cells along those path pass along the message of the neuron to other brain cells. Some pathways end and the message is not forwarded. The combination of brain cells and pathways between brain cells is how the brain processes and stores information.

To make AI happen we should be at least be able to mimic the brain cells and pathways functions. There are two options available; hardware and software emulation.

You could compare the brain (without memory) with a CPU. Current top-of-the-line computer processors contain 2–3 billion transistors. That comes close but each transistor has only a few pathways and is in the end only a transistor. If you would emulate the pathways the current CPU need to contain at least 50.000 more transistors than they today. Based on the Moore’s law (CPU transistor count doubles every 2 years) we can have to wait until 2025 to get to this point.

From a memory perspective you need to store the values of each of the pathways of the brain cells. This would require 10B * 10k * 1 byte = ~90TB of data. The biggest individual memory units currently available are 12GB. Applying the law of Moore again and we reach 90TB memory units in 2023.

With current technology we are able to emulate the brain function of an insect. Hence you see all those insect-like autonomous robots.

Based on these calculations it looks major progress can be made in AI in 15 years from now because the necessary computer hardware is available to be able to emulate the brain functions. Of course emulation is only the first step. The emulated brain also needs to be programmed to work. Much like any brain is programmed before birth.