Schematics for Displaying your Lego Creation

Properly displaying one's Lego creations is an incredibly important aspect of any true Lego fan's efforts.  To that end I have sketched out a stand system that can be made using 1/8 inch acrylic, a laser cutter or CNC machine, and a decently high resolution 3-D printer, or if you are willing to destroy some bricks you can skip the laser cutter3-D printer.

 The image below is a full render of what the base should roughly look like. 

The grid pattern you see at the base of the display stand is to allow for the user to position the supports as needed.  The grid pattern repeats every 8 mm, which is the standard spacing for the studs on Lego bricks.  

The curved pieces have two lower contacts to help keep them in place.  The top element is intended to mesh with the custom printed Lego Brick, that being said, someone could cut off that top contact point from the design and directly glue on a pre-existing brick.  For the cost conscious this would be the wiser choice, seeing as the cost of 3-D printing at Lego brick resolutions runs you something like $5/ brick.  

I would like to thank the author of robertcailiau.eu for their page on Lego Brick dimensions, the explanations on tolerancing rationals used by Lego corps was very helpful, and much faster to read than going through patents.

I will try to put up some engineering files later today.  Please note that I will not have curf corrections in the drawings as I cannot account for machining variances.

The Gourdinator

Hey you! Yeah you!  Do you have an excess of pumpkins, squash, and other gourds?  Then you need the gourdinator.  The gourdinator turns your pumpkan't into a pumpkan. (there is a reason I should never write dialogue for actual consumer products) Using sophisticated 3-D sensing systems and a multi-axis CNC machine, your gourds will be transformed with designs ranging from a traditional Jack-o-Lanterm to the face of alien creations out of your child's nightmares.

This idea was inspired by various companies that CNC their pumpkins during the Halloween season.

Can Stereo Lithography Printing Work in a MicroGravity Environment

With MadeinSpace investigating the potential of manufacturing in space a question for power nerds arises, is it possible to use stereo lithography style 3-D printers to create useful tools and objects for space bound explorers?  Theoretically the answer would be yes it is possible to develop stereo-lithography printers that work in space.  This yes comes with a number of caveats, starting with the challenges of working with fluids in a micro-gravity environment, without the aid of gravity, liquids tend to bunch up and create floating globs that can cause chaos on space craft.  (see vacuum toilets).  Ensuring that liquids stay in place can be done one of three ways*, store it in a container, use the force of air to position the fluid, or finally using centripetal force to "push" the liquid to the outside of a rotating body.  Using air to control the position of the photo reactive resin would most likely lead to a range of headaches that would make developing such a technology extremely prohibitive.  The remaining two options are two manufacture the entire object in a sealed container, similar to more traditional approaches in stereo lithography manufacture, but that doesn't involve any "fun" math, so I'm going to ignore this option, initially and go for the math approach, spinning a 3-D printer around a center point to simulate the effect of gravity.

In the image above we see a cut away that helps to highlight a concern of trying to create the effect of gravitational pull using centripetal acceleration (read spinning things around a center point).  The liquid reservoir will not simply lie flat within in its container while it is being spun out, similar to the water in a bucket curving if you spin it around, the concave shape of the liquid must be controlled, if it is too extreme the printer won't behave correctly.  Calculating the shape of the liquid in the container is relatively simple, as energy is conserved the photo reactive resin will take the path of least resistance, ie. the shape of the water will roughly follow the curvature of the path of the spinning object, you can see this effect in the image above.  An engineer properly designing this printing system is limited by two things, the maximum allowable difference in the depth of the photo-curable resin and the maximum allowable radius of rotation that can occur within the volume of a space craft, for example the ISS.

The proposed Centrifuge Accommodations Module, canceled after the 2003 Columbia disaster, was intended to have a 2.5 meter diameter centrifuge to allow for experiments on organisms and materials under various intensities of simulated gravity, while this diameter might not occupy the entire volume of the module, it provides a reasonable outer bound for diameter of the centrifuged printer system.

Calculating the height difference of the photo curable resin from the diameter of rotation is now a matter of trigonometry.

The image to the right is a zoomed in perspective of the totally not to scale reference image from above.
Here we are defining R as being 1.25 meters,
X is going to be defined off of the FormLabs Form1 printer for two reasons, 1) I know the number off hand it makes my life a bit easier 2) I want to suck up to a perspective employer.  X is defined as half the value of the width of the resin reservoir, or 0.0625m
(the Form1 is 12.5 cm accross)
With these two variables we have 2 sides of a right triangle making the last variable pretty easy to calculate the change in height.
which can be
rewritten as,


Plugging in the numbers we can now calculate the difference in height of the fluid from the center to the outside.  Where we find the liquid would be 1.56 mm deeper at the edge of rotation, and as it is almost as easy to calculate a large range of cases as it is just this particular case, the below graph shows the variation in fluid height as a result of the radius of rotation.

 It is reasonable to assume that if the printer is allowed to rotate at a radius of at least 0.7 meters, where the height difference between the fluid is less than 3mm that the printer would be capable of operating in a micro-gravity setting.

Alternatively engineers could build a system that closely resembles more traditional Stero Lithogrpahy rapid prototyping where the top of the printer is covered in a material transparent to UV light.

The purple represents the UV transparent cover, the blue is the working fluid.  As the container is fully enclosed the liquid cannot go anywhere during printing seeing as it already fills the volume of its container. The challenge for this design is the removal of the relatively large volume of leftover photo-curable resin at the end of the process.


While this was a fun thought experiment there are some legitimate concerns of using stereo lithography in a micro-gravity environment.
Do the benefits of this type of printer outweigh the complexity and cost requirements.  How would cosmic rays and solar particles effect the quality of the photo-curable resin while it is in storage, considering the intense energies of these particles it is worth determining how much of the resin would become non-viable during storage over time.




inks

http://www.cns.gatech.edu/~predrag/courses/PHYS-4421-10/Lautrup/shapes.pdf  page 59 (or 2 via scrolling) provides the useful math

open source physics textbook http://www.saylor.org/site/wp-content/uploads/2013/02/PHYS101_OpenStaxCollege_College-Physics.pdf


another reference http://cnx.org/content/m42084/latest/?collection=col11406/latest

http://en.wikipedia.org/wiki/Bucket_argument

Short one, more of a question on Lithography style 3-D printing

Would it be possible to make a photo-curable resin, that would behave differently depending on what frequency of light it was exposed to during the curing process?  Even more ideally could you tune more than just the color, maybe even the mechanical/chemical properties.

Stereo Lythography onto Existing Items

So I finally remembered an old idea and I'm kind of excited so I'm going to go reasonably technical.

  Current 3-D printers are designed to start from nothing and by extruding material, sintering metal, curing a photo reactive resin with light, etc....  On their own these various technologies for rapid prototyping can create a range of wonderful items, a big trade off for these existing rapid prototyping technologies is how long it takes to make an item and the cost of the materials used.*  Make Magazine recently posted about a software package that reworks item designs so that the majority of the item can be made from, relatively, cheap lego bricks, with only the most complex components actually made out of printed parts.  This is a fantastic step in decreasing the prototyping time of an item, but I feel more sophisticated and flexible solutions can be developed.

Imagine you are a tourist destination store or amusement park, your profits greatly benefit from being able to provide unique items for people to commemorate their visit.  While a standard 3-D printer would be excellent at providing the unique aspect, the necessary turn around time could drastically reduce sales, especially if the customization is rather minimal.  You need a 3-D printer that is smart enough to add material to an existing item, you also would need it to be easily handled so that any of your employees would be able to fabricate the memento without supervision.  What I would like to suggest is a printer that integrates the requisite technologies to do just that.

Figure 1
Step 1:The base item being inserted
 into the printer to be scanned

This proposed 3-D printer would need a 3-D scanner capable of accurately mapping and positioning whatever item was placed inside the printer, it would also need a grip system capable of holding whatever items were placed inside the printer and keep the object stationary enough that the object would not move during the print process.  Of the existing 3-D printing technologies I believe that stereo-lithography is most likely to be able to integrate this concept in the near term**.  Once an item is secured inside this new lithographic printer it would be scanned and mapped by the inbuilt 3-D scanner, this scanning would ensure that the computer has a very clear idea of where it would need to add material.  As each layer of material was cured the object that was being added to would be lowered further into the bath of resin, layer by thin layer the starting object would be transformed.  A formless basic action figure becomes a custom hero, showing all of the traits chosen by a family to commemorate their visit to Action Universe.

Figure 2:
Step 2-10,000: Layers of resin are cured onto the
selected item

I believe that an extrusion style 3-D printer could integrate this approach, but the system would require far more mechanical precision than a stereo lithographic printer.  For technologies like laser sintering I am more dubious that you could directly print onto an existing item and have it make sense, in theory a manufacturer could first print on a small containment wall, then deposit a layer of the material that they actually want to add, fuse the target material, add another layer to the containment wall, and repeat the process, but it feels like it would be less likely to actually save time in manufacturing.

Originally I had planned on using this post to improve my chances for applying to work at FormLabs, they have a 3-D printing system that uses stereo lithography, but I realized in writing this article that the approach I am suggesting for adding printed material to an existing object, would be more difficult to impliment considering the FormLabs printer uses a shallow resin reservoir design, Figures 4 and 5 show scenarios where it wouldn't be feasible to print directly onto an object using Form Labs style of printer and where it would be, respectively  In Figure 4, someone wants to print onto an existing object, but the desired start point for the print cannot be covered by the photo curable resin, consequently they will not be able to print directly onto the item.

Figure 4

Figure 5

In Figure 5 the user has selected an object with a flat surface that can lie flush with the resin reservoir, this would allow for printing onto the existing item.

In the majority of cases where users are simply trying to create something akin to a hood-ornament the could use 3-D scanners to create a mount that would then allow for the addition of other printed objects.  This concept makes the most sense for fully covering an existing item, like a Lego model.


*a kilogram of plastic for an extruding printer= $35/kg
Photo-curable resin = $150/L
Sintered Metal=$8/cm^3 (I couldn't find the price of pure feed stock, so I am providing the price per printed cubic cm (hey better than nothing))

**I haven't had a chance to work with stereo-lithography and so I am  making some light assumptions on the flexibility of the technology, if it turns out I am wrong please let me know.
*** the idea of priting custom toys for amusement park guests is not my own, I recall reading about it in both the book Makers, by Corey Doctorow and this article on Disney Parks unique princess toys.

A Kit of Parts for Front-line Manufacturing

The various branches of the United States Department of Defense have all started to make large pushes into developing unique capabilities in rapid prototyping capabilities.  In entry, Wise Welding Warriors, I noted how rapid-prototyping was being used to drastically reduce the turn around time between war-fighters finding critical problems in their ability to operate effectively and developing material solutions for that problem.  The logistical benefits of being able to build and repair components closer to the front-line are already impressive and will only become more useful as the capabilities of the various technologies mature.  Currently relatively simple mechanical solutions can be created by Rapid Equipping Force's  ELM facilities, the ability to integrate electronic components into design solutions will undoubtedly serve as capability multiplier.

Open source electronics platforms including the Arduino and Rasberry Pi have taken the maker community by storm allowing amateur inventors to create technologies ranging from automatic plant watering systems, to  pens that work in 3-D, to prosthetic prototypes, and semi-autonomous vehicles.  The consistent characteristics of these platforms, working in tandem with their opensource nature allows for creative talents to avoid reinventing the wheel, but instead refining a technology for a given need.  The Lego Mindstorms platorm has also unleashed unimaginable levels of creativity from its user base, by being both open ended in use and reliable.  This kind of open source creativity/capability added to ELM style operations could allow engineers anywhere in the world to develop advanced solutions for conflict regions around the world.

Within the realm of robotics technologies creators could know that they would have access to a micro-controller and assorted components that from the get go would be capable of being formed into traditional small scale land based robots or quadcopters.  As efforts were added to the platforms engineers might develop additional remote sensing capabilities or robots intended to aid local farmers in optimizing water usage for irrigation, aiding in good will missions to counter insurgent activities.

 A set database of standardized components as well as a shared database of tips and tricks would mirror current open source civilian projects.  This similarity would be extremely intentional, ideally the components used would also share traits with products already available to civilians.  For sake of security concerns there would be some rather significant differences between the platforms used by the Department of Defense and its allies and more traditional open source ecosystems.  The development community would need to be multi-tiered with increasing levels of security needed to access more sensitive aspects of the community portal, extremely general community work would work through a civilian accessible web host, while moderated the platform would most likely benefit from minimizing any heavy handed oversight by military command (voiding extreme scenarios).  At a higher tier, only recognized academic groups, contracting firms, and military personal would have access, sharing would be less immediate but still reasonably open.  The highest tiers would likely only need to concern a vetted group of developers who would be responsible for communication protocols and the source code of the devices.  This tiered system of development would work to prevent potential hazards highlighted in the Armed Forces Journal article "Print when ready, Gridley", where the author voiced concerns of design databases being hacked and mobile factories are transformed into a digital fifth column.

The hardware utilized by military personal would ideally be as similar in design as possible to the platforms available to the public, with key exceptions in the ability for components to communicate on military channels, which for obvious reasons should not be put out for general access, unlike many drone transmissions in Afghanistan.
DARPA has already begun work on developing open platforms for organizations to have a common base package for building a product around, the ADAPT sensor system is serving as the flagship technology.  The sensor package has already been used as a ground sensor and the control module for a quad-copter.

Wise Welding Warriors

As rapid prototyping technology has become more popular and affordable over the last decade, there has been a range of chatter and in some cases experimentation with integrating rapid prototyping technology into front line applications.   Think tanks associated with the Department of the Navy have put forth more long term suggestions, including the development of autonomous manufacturing facilities capable of filtering source materials for manufacturing war material from sea water.  On a more practical front the US Army is already beginning to test small scale platforms intended to operate at Forward Operating Bases (FOBs) in Afghanistan. These shipping container sized facilities, called Expeditionary Lab Mobile (ELM), house a range of tools for creating solutions to problems encountered by airmen/marines/sailors/soldiers serving on the front lines and are budgeted to operate with trained engineers who will design and fabricate what ever is needed.
While I am a huge fan of rapid prototyping technologies, I think that the Army's current approach to front line manufacturing facilities doesn't go far enough for the war-fighter.  It is one thing to shorten the development cycle for new tools for the front line, it is another thing entirely to have servicemen and women be the individuals developing that new technology.
In countless commercials recruiting for the US Armed forces the audience is told that the skills they gain while serving their country overseas.  With developments like the ELM the Department of Defense has a unique opportunity to provide our war-fighters with an invaluable skill that will last a life time.  In addition to having professional engineers on staff the armed forces should work to provide direct access to those serving.  War-fighters could be trained in the use of the entire fabrication facilities tools, with a certification program that would have published standards so that civilian employers would have a clear understanding of what skills had been gained during an individuals service.  Ideally the certification program would emphasize flexibility, any serviceman or woman would have the option of learning how to use the tools of the fabrication facilities, either while deployed or while working on base.  To promote participation in the Fab-Lab certification program the Department of Defense could sponsor a myriad of design competitions, and for challenges encountered on the front lines.   Officers serving combat duties should also be able to provide a cash bounty for the most effective solutions to their particular needs (preferably the creators of design solutions would receive both monetary compensation and active recognition by their command superiors) .
There is no guarantee that such a program would be perfect, but if the maker movement is any indication, the more talent we unleash to solve problems the better future we can create.

Gloves that fit like skin

Biologically capable 3-D printers are at the very early stages of creating a technology platform that should allow us to convert human stem cells into a viable alternatives to more traditional organ transplant technologies.  In 2011 researchers at Cornell made quite a bit of noise in the news when they said they had managed to print a replacement ear for a patient (although said ear was made of silicon, it served as a tremendous first step into helping the human body be rebuilt).  Last August researchers at Wake Forest School of Medicine published their work on improvements made in technologies capable of depositing skin cells directly onto damaged flesh, improving the healing time of the patient.  Recently scientists have released a paper highlighting drastic improvements in 3-D bio-printing that should make it easier to print out structures made from embrionic stem cells, providing potentially massive flexibility in the formation of replacement organs.
Medical advancements aside, bio-printers have created another potential avenue of research, the production of so called ethical meat.  By using various technologies researchers are working to create a meat source that only requires that your cut of steak is grown no full animal ever forming.  There are some questions as to the viability of such technologies as it would cost roughly $300,000 to make a single hamburger and steak is out of the question as the texture would be too difficult to achieve.
Fashion has also started to embrace 3-D printers as a way to create new innovations within their own field, with an entire show devoted to designers embracing new their new frontier.
What I envision is the merging of these worlds even further.  Imagine a leather jacket that fits like another layer of skin, with no seems to be seen, as none would exist.  By utilizing various printing technologies designers could realistically digitally develop a product for clients and then print out units on demand.  Even under the most ideal circumstances of innovation it is unlikely that clothing made in this way will be affordable to the masses anytime soon, but for those who need to spend a quarter million dollars on a rather tacky jewel encrusted cell phone, such rarity would impart these pieces of clothing with tremendous value.  The potential for environmental preservation should also not be ignored, as vat grown leather's cost is reduced the impact on species harvested for their fur, skin, feathers, or scales, should hopefully begin to rapidly diminish.  Few are likely to protest clothing that is made from vat grown skin cells as opposed to an endangered species.  Hopefully as technologies like in-vitro meats become more cost effective and lower on their impact than their traditional competitors, we can reduce our species burden on the world's ecosystems.
Follow  Up
So it turns out that the idea of producing bio-printed leathers is not unique (hopefully I will get cosmic brownie points for suggesting you print the leather to the final desired shape)  http://www.youtube.com/watch?v=waro4LJDZvU&feature=youtu.be&t=2m17s

Printing out Plants

Several years ago (or more, few of my older journals are properly dated)  I became inspired by developments I had seen in the field of 3-D printing technologies, especially those that were being developed to produce replacement organs.  The idea that you could work from a canvas of living tissue as opposed simple metals and plastics was wondrous.  From that overwhelming image came a question for me, why not print out plants or coral reefs.  With advancements in biotechnology we might have the ability to print new ecosystems.  I began to imagine cities where the walls of buildings were living trees, not just dead concrete and metal.  I have since learned that grafting of more naturally grown plant structures is by leaps and bounds more cost effective, that being said I think it would be really really awesome if we could expand urban green zones into the z axis.
Visual Follow Up (Feb 7 2013)

Apologies to whoever on Imgur I stole this from,
Reddit didn't provide any copyright info.

Imagine structures like this, but with tree branches extending out, providing additional shade and productive biome.

Making Satellites in SPACE!!

Building in space is an expensive task left to only the wealthiest and ... who cares? I want to make LEGOs for space.  A range of innovative individuals and groups are putting forth various ideas on how to reduce the cost developing the resource we know and love called space (terrible phrasing, what do you want, its not like I have an editor here)  Swarm satellites, zombie space probes, and 3-D printed applications.  Personally the approach that I would be interested to see in action (mostly because I think it is kind of a unique idea and I haven't spent 10 minutes on the Googles to shatter my belief that I'm original) is creating an open platform of space certified low primary components that can be assembled by robot in LEO (low Earth orbit) and then have their orbit adjusted according to mission requirements.

Figure 1) Traditional Satellite Launch

Unlike mass produced products like cars or cellphones, satellites are far less common with roughly 4000 listed payload launches and of that number roughly 1000 active platforms in Earth orbit these devices are of limited production runs.  Obviously aerospace manufacturers do not reinvent the wheel with every launch, much of the satellites basic functionality is well defined and roughly replicated throughout a technologies generation.
In Figure 1 you see a rather crude approximation of a launching an orbital system.  The fully assembled platform is launched from the Earth's surface.  Once in orbit the platform will unfold into its optimal configuration from the small volume footprint that was required for launch.  Another requirement of this approach is that the frame of the space craft must be built to survive the rigors of launch, adding to the launch mass.  Part of this additional structural support will remain with the spacecraft through out its operational life, increasing the quantity of maneuvering propellant required over the system's deployment.

Figure 2) Building in Space

What I would propose is that some the more commonly required components should be made into construction elements that can be added to the space craft in Earth Orbit. Step 0) Long before the mission critical elements of our system goes into orbit an established construction platform/system constellation is assembled in either Low or Mid Earth Orbit.  Step 1)  The assembled construction platform takes on supplies for its mission of satellite production.  Propellants (a) and electronic and mechanical components (b) are stored as part of the construction constellation.  To aid in the potential cost savings of this approach the aim of this methodology is to emulate cube satellite launches, parts piggy back into orbit on other missions.  The material stockpile can be built up in a piecemeal fashion in addition to the more traditional supply runs that are seen on the ISS.  Step 2)  An open platform components satellite is launched into an orbit that will allow it to dock with the construction constellation.  Step 3) After docking with the construction constellation, components are added to the satellite, for earlier generations of this technology the augmentations will most likely be limited to adding solar panels, providing additional propellant for maneuvering thrusters, and a radio/microwave dish.  As the capabilities of the construction platform improve and engineers learn how to best utilize this production paradigm the complexity what is built in orbit will incrase, eventually leading to a point where only base components are sent into orbit and all major assembly occurs in space.  In Figure 2) (d) is being used to indicate that a radio dish is being added to the base satellite (e).  Step 4) the fully assembled satellite has is moved into whatever its operational orbit might be.

Satellites will end their operational life for any number of reasons, colliding with orbiting space debris, becoming obsolete, the owners of the satellite lose control, exhaustion of maneuvering propellant supplies etc..  Under optimal conditions a satellite can be placed in either a decaying orbit, where it will burn up in the Earth's atmosphere, or moved into a graveyard orbit.  Additionally DARPA's proposed Pheonix program would attempt to breathe new life into systems once thought dead, by having a maintenance robot repair a selected satellite.  By designing satellites to  be compatible with an open standard for hardware and critical mounting elements, we open the door for a larger range of options for recycling mass in orbit.

Figure 3) 

In Figure 3) you can see a repair robot replacing a broken component with a rather happy working part that will allow the satellite to continue operation.  This approach effectively mirrors what is intended by the Pheonix Program but adds one major feature, a design meant to be reworked while in space.  Current proposals suggest that the system would require a wide number of tools to allow for reworking the satellite, standardized components for future satellites would drastically reduce what the repair robot would need to bring with itself.

Figure 4)  Returning to its spawning grounds the mature satellite
will now give its life for the next generation

For systems totally beyond their useful life span Figure 4) reverses the assembly process.  The old satellite is brought from its operational orbit, back to the construction constellation and broken down into its base components, where they can be used by future satellites.  The owners of the satellite can now resell components to others who may not have the same budget for space development.  In theory the Pheonix Program approach could also follow a similar business plan, but there would be greater capital costs for Pheonix (assuming the construction constellation exists, obviously)

As someone who does not have either the academic or industry experience to lean on in modeling the economics of satellite life cycles, I cannot claim there would be any actual costs savings, nor am I able to model what the ROI would look like over a given time span.  That being said, my gut says this could end up saving the space industry money. Other benefits from this approach could include, increased flexibility in mission planning, integrating more countries into developing space based technologies, and decreasing the quantity of space debris in Earth orbit.  

Follow Up (ok not really I just found out some final details near the end of writing and didn't know where to properly insert them):  While I still haven't exactly found the "LEGOs in space" approach, DARPA's System F6 initiative highlights a solution that is probably more reasonable, swarm satellites collaborating around a pseudo mother ship or as an emergent system. (the latest article on System F6 is here) That being said I think that my approach or other in orbit manufacturing systems will still serve as necessary component for expanding humanities capabilities in the heavens
Follow Up #2 (this time I actually hit publish before I added it)  While reading an article on space debris I learned that under the current approach to the Pheonix Program the repair robot must be manually operated, and deal with a rather long communication delay.  In theory a more standardized satellite design paradigm could help mitigate these issues.
Follow Up #3 (Jan 20 2013, I am so smart S, M, R, T ) so it turns out there is a full on lego approach to satellite design, although  the assembly appears to be more terrestrial at this juncture