Archive for Global Village Construction Set

HydraFabber Technical Update: Laser Cutter Design for Review, CNC Circuit Mill Ready for Build

Open Source Ecology’s HydraFabber, now in development, is a foldable, portable combination 3D printer, CNC circuit mill, and laser cutter. Its purposes will be to enable 2D and 3D rapid prototyping for open source machine design and to mill circuits needed for OSE’s modular machines in the Global Village Construction Set.

In coming weeks, OSE will take the HydraFabber to the finish line, realizing the dream of the 3-in-1 machine proposed by Leo Dearden and worked on by Nate Wettstein, John Kobmla Stager, and Tim Boyd.

“Closing in on the target!” Exec. Dir. Marcin Jakubowski examines a spindle holder.

At this point, the laser cutter design is ready for review—heads up, please, if you are a laser expert or have friends who are: we would like to have laser experts look at our design and calculations and offer feedback. We’ve already had much help from Tim Boyd, a laser expert and active contributor to our design sprints. Tim has produced the design for our laser-cutter component of the HydraFabber. The laser cutter enables 2D prototyping by cutting paper and cardboard patterns to be made in steel on the CNC Torch Table. In Part 1 of this post, Tim lays out the technical details and calculations for the laser cutter for review.

Dedicated Project Visitor (DPV) John Kobmla, meanwhile, is developing the CNC circuit mill part of the HydraFabber, and that work is nearing completion. In Part 2 of this post, we’ll take a detailed look at progress on the CNC circuit mill.

Part 1: Laser Cutter

Check out the conceptual diagram for the laser cutter and please pass this on to any of your laser expert friends. We are reviewing the current design and would like your feedback on (1) general design considerations, (2) verification of our calculations on laser cutting capacity, and (3) any comments on feasibility, especially if you have experience with lasers. Please send feedback to Tim Boyd.

10-Watt laser cutter overview

After the calculations below are reviewed and after we receive feedback, we will purchase the parts and build the laser cutter.

The laser cutter design

The laser cutter uses a focused diode laser to cut paper and cardboard by thermal ablation, or the vaporization of the paper fibers. This process eliminates uncontrolled combustion.

We will scan the laser position in X dimension, and the paper will be panned in Y dimension. Ablation requires highly focused intensity; therefore, high laser power is required.

The necessary 975-nanometer wavelength, 10-watt fiber-coupled diode lasers are now commercially available at low cost. The laser power can be delivered to the X,Z scanning stage by a multimode fiber optic. The laser power is then focused onto the paper with a fiber-coupled optical assembly. The assembly focuses the power in a 200-micron spot at a distance of a few inches from focusing optics. This arrangement allows smoke and particulates to be vacuumed away from the optics.

A simple calculation regarding paper-cutting speed

Please review these calculations for our 10-watt laser cutter:

Ten watts of laser power focused in a 0.2 mm diameter spot results in an intensity of 30,000 watts per square cm or 300,000 times the intensity of sunlight.

Assuming the paper absorbs 1/2 of the incident power (or 5 joules per second) in a 0.2 mm diameter spot and assuming a paper thickness of roughly 0.1 mm, 5 joules/sec will act on a volume of roughly 3 millionths of a cubic centimeter.

Given a mass density of paper of 0.7 gram/cc, the mass is roughly 2 micrograms.

The specific heat of paper is 1.4 kilojoules per kilogram kelvin, or 1.4 joule per gram for 1 degree centigrade.

All of these factors result in a temperature rise of the volume of paper of roughly 1 million degrees centigrade per second.

Assuming that 1000 degrees is sufficient for vaporization, then a period of one millisecond is required for each spot. This suggests a cutting speed of 200mm per second.

Laser cutter assembly

Requirements for initial test

Before the laser module, fiber assembly, and focusing optics are procured, we must decide whether commercial power supplies for diode current and thermoelectric control should be procured or built by us and then tested by experienced personnel.

Also, laser safety is paramount. The 975 nm wavelength is the wavelength presently favored because high-power modules are most easily obtainable at this wavelength. However, these are eye-hazardous wavelengths, so the paper-cutting operation must be completely shielded by plastic that is totally opaque at these wavelengths. We should investigate dye-impregnated vinyl or other transparent plastic for its optical density at 975 nm. Fortunately such material is available for industrial application for the high power Nd:YAG wavelength of 1064 nm. However we must have a minimum of equipment to assess light leakage.

Light-proof case

A big case, possibly one that folds up, will be needed to enclose the fiber and the X-Y axis. We are working on the first cut of a design for a frame that can be lowered down—a box of steel angle iron that will hold vinyl sheeting impregnated with dye that will filter out the light the laser emits, since that wavelength of light is dangerous to the eye. You can look through the vinyl and see the progress of the cut, but the vinyl will block the harmful 975 nm light, protecting the eyes from a burn or local blindness. It must be absolutely black at 975 nm to prevent light exposure to anyone who might be standing nearby. This is critical to prevent eye damage or even blindness and to meet OSHA requirements.

Vacuum pump considerations

The caustic of rays is the focus of optical power or radiant flux, or, more precisely, the geometrical curve of the envelope of rays where they focus concentrated light. In the illustration below, the caustic is the transparent object, red in color.

Caustic, depicted in red (detail)

The caustic of rays will encompass whatever smoke and particulates are generated. Because smoke will interrupt the power from the lens, it is essential to maintain a small vacuum current to clear the region where work is taking place. An aquarium pump used in reverse might be sufficient to remove smoke from the enclosure, or a small circuit cooling fan might be used.

Bill of materials
We are ready to source the parts for the laser. The total cost for the 10-watt laser cutter portion is about $2000, as follows:

Part 2: The CNC Circuit Mill

The CNC circuit mill will enable OSE to produce the circuits needed for modules in various machines of the Global Village Construction Set. For the CNC circuit mill, John Kobmla has built upon the Ilan Moyer open source spindle from the Center for Bits and Atoms. John is currently working on the control software for running the CNC circuit mill, utilizing Fab Modules from MIT.

John reports:

After a mere four weeks, the HydraFabber has a CNC mill spindle assembly. Now we move on to the milling bed and the mill controller—the Fab Modules. The CNC mill controller and bed are in the integration process and will be completed by Wed, Aug. 21st, 2013.

The journey has been interesting, to say the least, and fun, both for OSE and the HydraFabber Team. Our documentation shows how far we have come and the progress that has been made to bring us to the current achieved stage.

CAD picture of exploded spindle assembly parts diagram

To see how the spindle goes together, view our spindle assembly animation:

And here is the spindle installed:

CNC mill spindle assembly mount on the taz, soon-to-be HydraFabber

For more pictures, see John’s log.

Feedback is welcome. Special thanks to all our supporters and well wishers for all their encouragements and to those who have contributed to the various open source designs upon which the HydraFabber’s components are based. Our work stands on their shoulders to reach to realize new possibilities for open source rapid prototyping and circuit milling.

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Progress on the MicroHouse

Open Source Ecology’s two-module MicroHouse

MicroHouse Construction Manager Chris Reinhart is moving forward on the OSE Microhouse design. The Microhouse is a modular, low-cost, simple-but-comfortable, Compressed Earth Brick (CEB) house design. It is designed such that the different parts of the house can be build in parallel – walls, utility modules, roof sections, windows and doors, and others. We are approaching this design from a “Housing Construction Set” approach – where we are developing basic, interoperable, scalable, modifiable building modules. We are experimenting with the limits of earth housing as a building method comparable in cost and build time to standard stick-frame construction – while allowing for much longer building lifetime.

A two-module design has emerged, featuring a courtyard in between. One 12′ x 12′ unit will be devoted to work and sleeping space (possibly a sleeping loft), while the other will house a kitchen, bath, and dining space.

The Microhouse’s passive solar design for direct solar gain can be built using compressed earth bricks produced by our CEB Press.  The building collects heat from its southern exposure without losing it on the other three sides.

Design for direct solar gain—See Chris Reinhart’s blog, linked below, for larger image.

The bricks will be configured to create thick, insulating walls which will keep the MicroHouse cool in summer and will keep heat from escaping in winter:

Possible brick stacking patterns for MicroHouse walls

A reverse shed roof will allow for easy mounting of solar panels, and high windows are an option to vent warm air out of the building. In an innovative departure from conventional construction techniques, a modular roof design is being considered, with each module weighing no more than 200 lbs., so that a small team of builders can lift a module into position without the help of a crane. Compressed straw packed into each module serves as insulation. Chris plans to test and refine the roof module design concept before the actual build, as there is little information be be found on such modular roof design.

Proposed MicroHouse modular roof design

For evolving design details and planning, follow Chris Reinhart’s working design log here. Here at Factor e Farm, the Microhouse build, scheduled for September 28, will likely involve 24-28 people working in crews on various aspects of the building process so that build time can be minimized. The OSE team will be making continuing improvement to the CEB Press + Tractor + Pulverizer + Power Cubes to make it all happen.

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6-in-60 Video Update and Optimizing the Development Process

For an exciting taste of the action at Open Source Ecology’s HabLab, follow the ups and downs of the 6-in-60 Campaign in our no-holds-barred video update, part one. Watch Dedicated Project Visitors (DPVs) from Berea College help us to take new OSE machines from Open Source CAD designs to functional machines. Then confront, with our team, the problem that turned 6-in-60 into 6-in-90.  (Be sure to stay tuned for our second video update, now in development. We’ll fill you in as to how we turned challenges into opportunities in revising our plan for the 6-in-60.)

 

Despite delays caused by supply issues, there have been some great successes so far: The Ironworker prototype went together in about 12 hours; the backhoe’s pivot, stick, boom, and bucket all went together well; and we have made good headway with the tread for the Microtractor. Meanwhile OSE’s new prototyping tool, the HydraFabber, is being put through its paces. John Stager, a member of Team HydraFabber, began testing its 3D printing capabilities on August 1.

HydraFabber Test

John Stager, assisted by David Preiss, tests the HydraFabber as Lucas Warner observes.

DPVs Target Engineering Development Processes

During the first week of August, we welcomed Scott Eisele and Jonathan Miller as DPVs. Both Scott and Jonathan come to us from Vanderbilt, where Scott is a graduate student of Electrical Engineering and Jonathan is a student of Manufacturing Engineering. Their arrival at OSE could not be more timely and helpful, as the OSE team, with their input, maps out an improved and robust product design and prototyping process.

Scott will be developing a two-month schedule to build LifeTrac 6, along with necessary protocols and templates to apply/evaluate elements of our new development processes. Scott and Jonathan will be collaborating with OSE on integrating advanced engineering analyses of our product design process via new software in development at Vanderbilt University’s Institute of Software Integrated Systems–the META Tool suite. The META Tools are a development effort funded by DARPA, whose ultimate goal is to improve the existing systems engineering, integration, and testing process.

This analysis has the potential to assist us in achieving OSE’s rapid engineering and prototyping goals. Results will help OSE plan/schedule, streamline operations and resources, communicate, track, and document projects effectively and efficiently. An optimal development process can address the kinds of real-world challenges projects encounter. Though this aspect of our work may sound a bit dull compared to watching steel cut on a torch table or cool machines roll out, it is the refinement of an optimal development process that makes exciting results possible, not only for Open Source Ecology, but for anyone who delves into developing and producing open-source hardware to help build a better world.

Coming soon: More on the MicroHouse.

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The Liberator – CEB Press Prototype IV – Design Complete

We’re pleased to announce design completion of Prototype IV of the Compressed Earth Brick (CEB) Press.  The machine has come a long way since Prototype I. The main changes since Prototype III - part of our Christmas Gift to the World of 2011 -  includes redesign of the hopper, a stronger frame, the next iteration of the automation controller, and general  streamlining of the design for fabrication.

Below is a video history of the Liberator from 2007 until present :

The CEB Story 2012 from Open Source Ecology on Vimeo.

Below is a video illustrating the latest 3D CAD of the machine.


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The improvements are detailed as follows: Read the rest of this entry »

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The LifeTrac Story

Here is a historical perspective on LifeTrac since September 2008 – the completion of LifeTrac Prototype I.

The LifeTrac Story from Open Source Ecology on Vimeo.

Right now we are using the LifeTrac to trench water lines for Factor e Farm. LifeTrac now has a total of about 200 hours of operation. The modular Quick Attach Wheels are working well. They have a total of 4000 pounds of pushing force with 4 wheel drive. The bent loader arms improve balance.

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Open Source Ironworker Machine – Prototype II Completed

Hello World, it’s Brianna again, with the final update on Ironworker Prototype II. You can see former work on Prototype I from 2 years ago. See the wiki for more details.

The Completed Ironworker and me

The build of the Prototype II has been completed  with great success on some fronts, and failure on other fronts. The machine was successful in that it shears even more than I’d specified, and that it actually works. The failures were in how long the machine took to produce (see my initial build proposal), how much the materials cost, and that I didn’t finish the punch element.

The current state is that we have a functional prototype, but still don’t have CAD or full documentation on how to build it. My Sketchup model is not entirely up to date either; it needs to have the updated shear tables, updated clamps, the reinforcement plates on the back side, and parts of the vertical linkages which had to be torched away. If anyone is interested in building, I can tell you the changes I had to make. Just email me at brianna at kufadesigns dot com.

I do not have any plans for finishing the remaining documentation, as I have moved back to California and will be working full time in the fabrication industry. OSE is looking for a draftsman to finish the CAD and 2D fab drawings for the machine. See the summary of existing documentation.

Successes

First, for the successes: the machine has been tested and can cut up to 1”x10” flat steel, and 3/8”x4”x6” angle steel. It should cut up to 3/8”x6”x6” angle steel, but we didn’t have any on hand, so we didn’t test it. Here’s a video of the testing:


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The cuts were far closer to perfection than I’d hoped. What I’d been looking for in the cut was that there be no burr, and minimal deformation along the length of the cut. The cut was cleaner than any cuts of similar magnitude which I had seen on an industrial machine. The cleanliness of the cut is very difficult to achieve, as it requires the blades to be perfectly parallel, and to have a gap between .007” and .010”, which required very precise machining.

The 1"x10" cut

The 3/8"x4"x6" angle cut

The testing went smoother than expected, with only one failure. Read the rest of this entry »

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Factor e Farm Update: June to July

Hello everyone, sorry for the delay between blog posts lately. I’m Parker Bonnell, one of OSE’s newer staff members, working primarily with Marcin and Aaron on organizational development.

The last month has been a busy one at the Factor E Farm. Our population is now in the double digits, fluctuating at around 14 people on-site. This boom has been a doubled edged blade though. While it has led to greater progress on multiple fronts, (GVCS tools, agriculture, organizational development, and construction) it has also caused some issues with infrastructure breakdowns due to the rapid increase in population, and subsequent demand.

GVCS Tools

As some have seen from YouTube updates, Brianna (with CAD help from Emmanuel Carvajal and thanks to Roger Olson for fabricating a shear blade) has completed the Ironworker. It can shear up to 1”x10” steel flats with 100+ tons of force at the linkage, and roughly triple that for the angle shear. A more detailed blog post about it should be forthcoming.

Great strides have been made with the cold saw, which is nearly complete, and should be running by the end of the week. The torch table is also moving along nicely, and is slated to be finished within 3 weeks. Lastly, the sawmill while completed awhile back, has yet to be tested. This will hopefully change sometime in the next few weeks. We’ll keep you posted as things develop.

Agriculture

Gabi, our Agricultural Director, has been busy since she arrived last month. Working with other interested individuals on the farm, she has begun charting a long-term livestock/agricultural management and development plan that will navigate the farm as we move forward. In order to inform this process, land surveying has also begun.

Contour map of FeF

On the more material side of things, we have bee receiving a steady stream of raw milk (about two gallons a day) from our newly acquired bovine friend, aptly named “Good Cow.” We have also been using the excess milk, with progressively greater success, to make butter, with plans for cheese and yogurt. Our goal of meeting all dairy needs in-house is well on it’s way. Poultry-wise, less so. While we have ten or so laying hens, and more roosters than we need, they are laying few eggs in the heat of the summer. This should pick up by next Spring with our new generation of chickens—currently chicks that are still in their adorable stage of life.

Some garden beds have also started development, both behind the HabLab and alongside the old workshop. While it’s a bit late to plant much for harvest this year, we hope to enrich them for next Spring with compost and manure. We also have a newly constructed horto domi, built by Will Bratton and Samuel Bagot, which serves as a mini self-regulating greenhouse. We also just got some rabbits, which can  produce more than 100 lbs of meat per year.

Organizational Development

In this department, a number of balls are rolling in different directions, with the current focus on recruiting, flash mobs, team development, and documentation. In the last few months, Marcin stepped up recruiting to bring in the current group of folks now at the farm. A second round of recruiting is on its way, and we’ve been working to streamline the process, as well as reach a somewhat wider audience. In tandem with this, a database is being pieced together in order to organize applicants, and serve as a storehouse of contacts when we start utilizing the flash mob system on a regular basis.

Along with recruiting and flash mobs, everyone at FeF has also been working out how best to live together; what responsibilities everyone has and how to communicate most effectively when making group decisions and in general. This is an ongoing process, and if there’s interest from our readers, can be expanded upon as things progress.

In terms of documentation, we recently hired our first documenter, Tristan Smith. A talented videographer (formerly at WikiLeaks), Tristan has started by focusing on production of a short film that summarizes the essence of Open Source Ecology–slated for completion around late August. After that, he’ll be putting together high-caliber weekly updates about the goings-on of FeF, and other videos as needed.

Short video mood board proposal for OSE

Construction

On this front, the most notable developments consist of resumption of work on the HabLab, infrastructure/agricultural development plans, and completion of Vann’s hexayurt (which will be detailed in an upcoming post). While the HabLab is mostly complete, we’ve begun the final stage, consisting of finishing the four side-rooms on the east side of the house, wiring the unfinished outlets throughout the house, and stuccoing the unfinished walls. Once those are complete, all that will be left is setting up a heating system in time for winter. Moving forward from there, plans are being developed for a number of infrastructure and agricultural projects. Some notable potential projects include a cistern for rainwater catchment and well-water storage; burying water, power, and internet lines; a pond for additional water storage and irrigation; a possible secondary greenhouse, and keyline design with strategically placed berms and swales for efficient irrigation of crops.

Issues

As mentioned, our rapid population increase has caused some problems, which has slowed development in other areas as various folks work to troubleshoot the issues.  Water has been the primary trouble, as our well, dug 4 years ago with a submersible DC pump, hasn’t been able to produce enough water to meet demand. Our water storage tanks, exposed to sunlight, also began developing some algae, which led to two people getting sick. We have installed a reverse osmosis filter, but because of our water demand, not everyone was using it. It’s use has mostly remedied the potable water issue, and we plan on installing an ozonator or UV filter to further treat the water. As for supply, plans are in motion to dig another well – we  got Mark Finch to drill test holes and identified a 1 gallon per minute location. We will start rain catchment from the HabLab, and store water in an underground gravel cistern. Furthermore, we plan on linking up with the town water system, which will serve as an emergency backup.

Aside from water, there have also been some power and internet hiccups, but these are relatively minor problems, and will be detailed further another time. We are still electrically off-grid, and we are considering a biogas digester cooking gas/electrical system.
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That about sums up the recent progress at FeF. Stay tuned for more frequent updates. Part of my role is to produce a weekly blog post, since Marcin has less time for this due to his schedule. Things are settling down as we regroup and reorganize.

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Call Out for Inverter Project


Hey all, Vann here. If you have a background in Power Electronics, and are interested in acting as a consultant, mentor, or remote developer of our Power Inverter project, please contact me at [email protected].

We’re just starting and thus still defining our design parameters (in accordance to OSE Specifications), but the initial goal is to develop an inverter capable of taking up to 72V DC and outputting 120v AC, say up to 5000W. Eventually we’d like one with three phase power, perhaps expandable via modules. And we’d like to do all this using a (so-called) modern, high frequency design, to help keep component costs low. Read the rest of this entry »

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Project Progress and Scaling

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Global Village Construction Set development  is scaling. There are currently 9 projects under active development and 3 full time developers besides me – Aaron Makaruk, Brianna Kufa, and Yoonseo Kang, two of which are currently off-site. The active projects include: the Ironworker Machine (build started), open source Tractor (modification field testing), CNC Circuit Mill (build almost complete), CNC Torch Table (build started), Dimensional Sawmill (build to be resumed next week), Heat Exchanger (prototype 1 coil done), Gasifier Burner (complete design, rationale, CAD, cam files- details in next blog post), Modern Steam Engine (parts kit arriving next week), and Backhoe (design challenge is up at GrabCAD). You can download a linked map by Aaron that shows the scope of some of the activity in the USA.

Most intriguing to me is two of high school engineers from Pasadena- who are replicating LifeTrac independently – with a goal to donate it to South Central Farmers in Los Angeles. See their work and the LifeTrac t-shirts in their fund-raising effort.

Development priorities for this year have been outlined in the OSE Enterprise Plan video – which we are passing on to potential investors. More current priorities for the next few months are outlined in Read the rest of this entry »

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Ironworker Update- Ready to build!

Last week I said I’d have the complete OSE proposal and Sketchup done for the ironworker by Friday. I didn’t get it done by then, but I am prepared to start building next week. I finished the majority of the OSE Proposal, see it here. I’ll be posting my engineering calculations onto the proposal when I get them scanned in. I also generated a Bill of Materials with most of the costs listed.  I’m waiting on the quotes for the steel; these should come in Monday morning. I plan on having all materials purchased by Tuesday, and begin building as soon as I get materials to work on.


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