2020 HDP Dream Team: CalEarth

The 2020 HDP Dream Teams are participating in a two month engineering sprint to address their nonprofit partner. Follow their journey here.

Similar projects worth following
The Challenge-

Automated Options for
SuperAdobe Building Processes:
One potential drawback to the SuperAdobe system is that it’s a very laborious method of construction. The intensity of labor accounts for the vast majority of building expenses.

This challenge asks teams to automate or mechanize parts of the building process in order to maximize efficiency, and drive labor costs down, without compromising the integrity of CalEarth’s vision to ensure accessibility and affordability of the technology.

The Team:

Sameera Chukkapalli
Architect & Director of NeedLab
Spain, Barcelona, Barcelona City.

Jason Knight
Product Designer
Eindhoven, Netherlands, Eindhoven

Alex Whittemore
Electronics Engineer
USA, California, Redondo Beach


CalEarth's mission is to further the research, development, and education of Superadobe, a safe and accessible form of Earth Architecture that provides environmentally and financially sustainable living spaces. CalEarth is engaging in ground-breaking research and education that fundamentally transforms housing options worldwide.


Increase the demand for sustainable construction by creating a global trend for “Superadobe” homes by flag shipping in the US and Europe.

Key Point:

  • Developed countries set the trend for building and lifestyle


  • Increase market share and mind share of SuperAdobe
  • Make SuperAdobe “A thing” in developed countries
  • Propagate SuperAdobe outword


  • Make construction less labor-intensive for well-resourced deployment scenarios in developed countries.

HDP 2020 Dream Team Initial Concept Review: CalEarth

Summary of three weeks work here. 

Pain-points (Chosen)

  • Labor intensive 
  • Compass - Profile sail
  • Mechanism to fill the bags
  • Ability to mix soil and control humidity
  • Plastering
  • Burlup bags Vs Plastic bags
  • Move material, Vertically
  • Safety during construction

Key Research Leads

Profiling of the structure

There is dependence on the person doing the “compass profiling task”. The rest of the team members have to wait for this person to indicate where the next layer is placed and how much is the overlap. Finding an alternate way to make the profiling of the domes easy that would save a lot of time and money (as workers are waiting). We’ll be presenting

  • The “LIDAR Compass” concept; a high-tech highly-integrated highly-flexible approach (still relatively cheap at ~$350)
  • The “Pipe Sail” concept; a relatively minor variation on construction and usage of the current sail concept. ($ 35)

Make the build appealing and less labor intensive: Develop compacting and filling tools that are automated. These concepts include

  • A bag funnel to assist in bag management and earth loading to hopefully streamline handling
  • An Earth Extruder which could automate both filling and potentially packing as well, 

Abstract Presentation.pdf

Hackaday Prize Dream Team CalEarth Initial Concept presentation.

Adobe Portable Document Format - 5.14 MB - 07/21/2020 at 16:52


Research line two.png

A low-tech prototype solution sketch.

Portable Network Graphics (PNG) - 137.01 kB - 07/14/2020 at 15:14


Research line one.png

A medium-tech prototype solution sketch.

Portable Network Graphics (PNG) - 186.94 kB - 07/14/2020 at 15:13



Manual for the LIDAR we are running experiments on. This is the product currently in testing - You can expect some hacking and some improvements from our end to make this product both user friendly and purpose-oriented for the CalEarth construction site.

Adobe Portable Document Format - 1.64 MB - 07/14/2020 at 15:03


  • LIDAR Compass Milestone 1

    alexwhittemore2 days ago 0 comments

    Milestone 1 isn't fundamentally complex, but here's some proof that it works! Most of the effort spent on this milestone actually went into discovery and experimentation with things beyond the milestone goal, like figuring out data formats and available information, how the LIDAR device works in practice, and so on.

    Have a look at it working to profile a straight wall below:

  • LIDAR Compass Project Plan

    alexwhittemore2 days ago 0 comments

    One of the most important strategies for actually getting complex work accomplished is to break the complex goals down into more tractable, bite-size problems that can be checked off a list in-order, and that build up to the complex finishing point. It can be easy to see designs from an overly-simplified 10,000-foot view and think, "oh yeah, for sure I can accomplish that by then!" And you may well even be right about that - I think that's true for this LIDAR design concept. The very beauty of it is that most of the complexity is available off-the-shelf, and the end-use can be boiled down in features to a fundamentally very basic proof of concept. 

    But thinking like that still obscures the actual effort that's required to accomplish the end goal, and adds the mental overhead of having to figure out which piece to bite off next. Thus, without further ado, and arguably later than we should have gotten around to it, I present you with a list of LIDAR Compass milestones and scheduled completion dates:

    Vertical wall verifier POC.

    8/7/2020 (That's today!)

    A simple iteration of the device that measures the distance to a vertical wall at 0° then verifies via on-screen feedback that the next few measured points are, indeed, on that same wall (plus shows their error). This is a very simple test case that, more than anything, proves I still know how to do basic trigonometry. If the POC works, it will basically light up a table of values in Python with "OK!" when the device is oriented perpendicular to a nearby wall, and those values will fall out of "OK" if the device angle changes at all. This will also start giving us a good idea of how much distance error there is in the LIDAR points, given that the walls of my house can be verified straight.

    This milestone is due today, and isn't actually done YET, but work is going smoothly and at this point I'm spending more time on nice-to-haves and future work than on just knocking out the milestone itself.

    Normal room verifier POC


    Same as above, but instead of only assuming one infinite wall, takes a model of an actual square room and verifies all points in 360* based on that. Assume a fixed distance from the ground, and fixed observation angle relative to the room. This isn't a huge step on top of the first milestone, which is why it's so close in time. But it is a big step in usefulness of the system, and sets us up nicely for the next milestone.

    Laser feedback POC


    Builds on the above POCs to include visible-laser projection of go/no go onto wall. This is probably the biggest individual step of the project, and it might be ambitious to get it accomplished in only one calendar week. In theory, it's as simple as anything else, but in practice, it's the one piece of system integration where there's no prior-art, and it's where all the unknowns lie. For instance, the laser pulsing system may need to be independent from the Raspberry Pi running the show for reasons of time-stability, since the Pi processing and GPIO is hardly real-time. It may be possible to get the rotation synchronization signal for the LIDAR rotor directly from the LIDAR itself, but again, real-time constraints may not be sufficient in practice, and we're not even sure if the T0 of rotation is even available in software. This may require adding an external hall sensor to measure and time rotor movement, which isn't fundamentally complicated but IS a significant addition to the project scope. And so on.

    Self-contained POC


    All of the above, running independently on a raspberry pi with some kind of remote login. In fact, we'll probably already get to this point by necessity as of the previous milestone. But one thing we haven't talked about yet is ingesting arbitrary geometry to profile in the form of a 2D DXF, and this milestone will contain that deliverable as well. This may well be a zero-effort step in terms of hardware, but once again DXF processing is, in my opinion, where the real software unknowns...

    Read more »

  • Earth Funnel Quick and Dirty Prototype

    Jason Knight07/30/2020 at 21:01 1 comment

    This week the goal was to make a quick and dirty prototype of the Earth funnel. There are n Fablabs available and not enough time to wait for a commercial laser cut service. So I used a projector, to project the net on to a piece of plywood. I calibrated the scale with a caliper and traced over the net manually then cut it out using a jig saw.

    I then clamped the sheets in to a cone profile and used a rivet gun to pop them in place.

    Finally I ducttaped the section on to an old plant pot which was congenitally the same diameter and length as the tube we intended to use. A handle cut from an old plastic oil bottle was taped in place.

    Note: the purpose of this prototype is to test the mechanical feasibility of using the tool to fill the bags, not the build process or final materials.

  • Low tech pipe sail compass.

    Sameera Chukkapalli07/29/2020 at 11:05 0 comments

    The pipe sail Compass - Measuring tool used to indicate the placement of the next bag

    As a builder is placing super adobe bags in the shape of a circle a compass is needed to indicate where the next bag placement has to be. 

    Base holder: 

    Is the fixing point of the pipe compass to the ground. The holder needs to be strong to with stand the rough use of the compass throughout the build process + the wind loads on the site + the rotation/lateral sliding of the moving post. Different base holder designs will be tested with active forces imposed on it - in the coming week to find the most appropriate/cost effective solution.

    Moving Post:  

    This is the horizontal member which is moved to get the next bag placement location. this element can be rotated along the vertical post axis and it can moved laterally to get the desired measure for the bag placement. 

    Vertical Post:

    It is the fixed member of the compass - fixed firmly to the ground. This gives the height of the built and the support for the moving post. 


    Is the element which is moved along the axis of the vertical post and it holds the moving post. It enables the moving post to move laterally in order to indicate the placement of the next super adobe bag. The joint has a LCD display which shows the measure and two buttons which can be used to reset and start the measurement. The moving post is moved laterally to get the correct measurement on the display.  

    Pipe compass - movement

    This GIF displays the lateral movement through the joint to indicate the placement of the next bag. 

    This GIF shows the detail of the joint. As the MP slides through the join the movement is measured and displayed on the LCD screen. The two buttons on the joint are used to reset and start measuring. 


    Moving post: MP

    Vertical post: VP 

    Base holder: BH

  • Baby Steps: Getting a Point Cloud

    alexwhittemore07/29/2020 at 05:07 0 comments

    I'm just starting to prototype with the RPLIDAR A1, and was pleased (after all that effort tonight thinking about rotary hammers) to get a point cloud up and running in ROS Melodic. That W looking thing moving around in the middle is me and my arms, trying to make a right-angle with my palms.

  • Sidebar: Addressing pain points with off-the-shelf solutions

    alexwhittemore07/29/2020 at 03:57 0 comments

    During our initial investigations and ideations, we identified a few different somewhat-obvious pain points with respect to reducing the labor intensity of SuperAdobe, as well as a few more surprising pain points. In the end, the solutions we chose to work on addressed two specific items:

    1. The bottleneck of handling compass measurement for layer planning (addressed by the LIDAR Compass and Pipe Compass concepts)
    2. Fatigue and speed associated with bag-filling (addressed by a slightly more purpose-built earth funnel than existing ad-hoc solutions)

    As conversations and development progressed, a pain point came into sharper relief that we'd previously considered, but dismissed: tamping.

    Labor Intensity of Tamping/Compacting

    While building a SuperAdobe structure, each layer must be compacted for shape and structural integrity. Layers must be uniformly flat on top so that loads are distributed properly through them, but they also must be compacted to a specific minimum pressure so that they don't crumble or break unexpectedly under load. Specifically, a given layer needs to be compacted such that after curing, it bears a pressure of 300psi without breaking or crumbling inside the bag. 

    It turns out that achieving this level of compaction isn't very difficult, and is typically done by hand with a tamping tool most often used for leveling gravel or dirt:

    Han tamper

    In terms of achieving the necessary results, this works just fine. The problem is, a single SuperAdobe dome has many hundreds of linear feat of bag to compact, and doing this work is tiring on top of all the other manual processes that have to take place. It also makes the build process less accessible, as tamping requires a higher level of fitness and stamina than other processes, where fitness can be traded for speed more fluidly. 

    Introducing Power Tools to the Mix

    Luckily, laying SuperAdobe isn't the only construction task that requires tamping, and plenty of options for power tools to do this job already exist. For instance, compacting plates exist for jackhammers:

    compactor plate for demolition hammer


    hilti electric jackhammer/demolition hammer

    And for larger areas, an easier-to-use option is the plate compactor:

    The problem is, both of these options are unwieldy and potentially dangerous perched at the top of a SuperAdobe dome, and both are terribly overkill for the compaction pressure required, to boot.

    Luckily, there's one last option you can find on the shelves at Home Depot that might just do the trick: the rotary hammer.

    The Rotary Hammer: Just The Ticket?

    If you're like me, you probably used to walk through the tool aisle at Home Depot or Lowes, see this tool, and think "Man, how on earth is that drill so big?"

    And as far as "drills" go, it IS big.

    You also probably have no idea what the difference is between a "Drill," a "Drill/Driver," an "Impact Driver," and a "Hammer Drill" (And why on earth do I need an Impact Driver AND a Hammer Drill in the same kit?!). It's true, they all do EXTREMELY similar jobs, but there are subtle yet specific differences in the mechanism each uses that makes each suited to a particular job over others. In brief:

    • A drill spins, usually with variable speed. It is used for drilling perpendicularly into things, with tools like twist drills, spade bits, forstner bits, and so on.
    • driver is much the same, but has an adjustable torque-limiting clutch so that you can drive screws without putting the drill itself through the same hole as you finish. You'll notice nearly every cordless drill on the market is, in fact, a drill/driver.
    • An impact driver is a lot like a drill/driver, but it usually DOESN'T have a clutch mechanism, and instead has a radial hammer mechanism that serves to create a torque impulse. Imagine that you're driving a bolt with a ratchet. The bolt simply won't go any farther, so you holt the ratchet near the head and hit the handle with a hammer. An impact driver does this hundreds of times a minute. It doesn't have a torque LIMITING mechanism, but it usually has a speed control so you can throttle...
    Read more »

  • Abstract Presentation Slides

    Jason Knight07/25/2020 at 17:45 0 comments
  • Funnel quick and dirty prototype

    Jason Knight07/24/2020 at 20:35 0 comments

    Despite fovucsing on the LIDAR and Compas solution, cal earth were still curious about the feasbility of the earth funnel idea (see abstract presenation for detail.

    I began prototyping the funnel solution to test its viability.

    I reahched out to several labs and began the conversation about protoyping at their facility.

    A net to quckly laser cut the funnel was exported from the Rhino model using the UnrollSrf tool

    Laser cut profile:

    (Black = cut, green = score)
    The net will be cut from plywood to test its funtionality. Tabs with rivet holes have been added so that it can be assembled with minmal effort and tooling.

    The corners have been rounded as Marco from CalEarth informed us of experiances in the past with bags tearing when similar devices have been used.

  • Solidifying Objectives and Resource Planning

    alexwhittemore07/22/2020 at 18:31 0 comments

    Engineering is all about resource management, and balancing cost with value delivered in the end product. In our case, operating on a super-accelerated timeline of three months from project brief to system delivery, the most important cost we have to consider is engineering time. 

    How to Prioritize Ideas

    In the concept phase, we've been lucky to find a veritable wellspring of awesome ideas. From measurement and process to physical tooling, there are TONS of things we could develop to fulfill project goals. But with three people and three months, there simply isn't engineer-time to address all of them. We simply have to pick and choose. 

    The ideas that have floated to the top of the concept phase, in our own minds and with CalEarth as well, are:

    • Compass Improvements
      • LIDAR Compass
      • Pipe Compass
    • Bag Filling
      • Hand loader
      • Machine loader

    Each idea has a (somewhat unquantified) development cost associated with it, and a (somewhat unquantified) value as well, in terms of the expected productivity improvement in end-use. The idea of resource management is to focus the input on the ideas which promise highest end-use value for the lowest input effort.

    For instance: the machine loader idea is highly promising. Unfortunately, it's also likely very expensive to prototype and refine, and nearly impossible to develop without in-situ use on a CalEarth project. The likelihood of developing it to maturity on our short timeline is low, even with substantial effort. Even if it promises high ultimate value, it doesn't promise high value/cost. 

    Something similar is probably true of the LIDAR compass - on the one hand, there's a ton of excitement for this idea both on and off the team. But in my professional experience with complex products like this one, there's a huge risk that we develop the product to 90% maturity in three months and produce something that works and proves the point, but lacking the extra 10% polish, it's simply not useful in the hands of end-users and can't deliver on its high promise. It would be a huge bummer to spend this time and energy on something that's "close, but no cigar."

    Luckily, the two remaining ideas on our list are low-tech and, at least in theory, should be quite simple and fast to develop. 

    The Hand Loader is really the epitome of low-tech: a simple structure with no moving parts that could be made out of any number of materials. The prototyping path for this product is terribly straightforward: Build the idea out of whatever material is easiest, try it out filling bags, and see what needs improvement. Then, use this learned experience to select better materials, and minimize production effort and cost from there. Most of the effort for this idea is in testing, which is a pretty good place to be in terms of a product design lifecycle.

    The Pipe Compass has a bit more to go wrong in practice, but falls into a similar vein that most of the effort seems likely to be in testing. Luckily, "testing" probably doesn't require full-scale super adobe dome construction to get good feedback. Simply building an example and "going through the motions" should glean lots of useful insight. 

    Our Strategy

    Given that the two "simplest" ideas also promise excellent end-use value, it's clear that those should be prioritized. We've collectively decided to apply about 20% of our time and effort to the hand loader idea, and the other 80% to the compass ideas. Specifically within the realm of the compasses, the priority will be the pipe compass, operating under the expectation that we can develop that to maturity with time left over to address the LIDAR compass, minimizing risk that we end up delivering "a lot of nothing useful." 

    As a team, we feel strongly that we'll be able to deliver "all of the above." The idea of this strategy and effort breakdown is to attempt that in a way that maximizes value delivered in the event we fail to achieve every goal. As a secondary goal, any loose ends we do end up leaving...

    Read more »

  • Compass

    Sameera Chukkapalli07/21/2020 at 16:51 0 comments

    The domes we build at Cal-Earth primarily use the lancet shape for a variety of reasons, and you need two compasses to achieve this shape.

    The height -

    Compass determines the placement of bag (its radius) at any given elevation and is a fixed measurement tool which never changes.

    The center -

    Compass defines the placement of the bag (its radius) along the entire course of a bag. The center compass’s measurement always changes at each new elevation.


    • Cheap
    • Requires a fair bit of skill to operate
      • Build crew may waste time waiting for compass operator.
    • Prone to integrated errors (a small mistake may invalidate an entire layer or more).

    Low cost, low tech solution ideation 

    Prototyping the first pipe sail idea. Currently made of bamboo to use less plastic in the prototyping phase. 

View all 22 project logs

Enjoy this project?



Similar Projects

Does this project spark your interest?

Become a member to follow this project and never miss any updates