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Step 3: Vacuum Robot

Another major limitation of today’s additive manufacturing techniques is linked to the unidirectional nature of layer orientation, creating an inherent weakness. Additive manufacturing allows for heterogeneous optimized distribution of matter. To take advantage of this, and not succumb to this limitation, we used structural optimization tools to create a second layer of material over the shell. The material is also closely aligned with the direction of stress, finally optimizing both orientation and thickness of the shell structure. The data derived from the structural analysis is then translated into paths for the third and final robot, the Vacuum Robot. Using a vacuum generator this robot attaches to the surface of the previously printed structure. Moving freely over the first shell on its tracks, depositing material on the surface of the shell, enhancing its structural properties. This task can be performed by one robot, or a swarm of robots working in coordination.

Consulting papers below:

http://link.springer.com/article/10.1007%2Fs10846-013-9820-z#page-1

http://jin-shihui.com/minibulders/Schmidt12.pdf

The Vacuum robot size 30*27*12 cm, weighs 2.1kg

Tools and materials:

-Makerbeam

-Dynamixel ax-12 servos *4

-Silver Duct Tape

-Smoothon Ecoflex Silicon 00-10(softest)

-700w handheld cyclone vacuum cleaner. We used the Core.

-Foam for CNC milling

-4mm acrylic for laser cutting

-Motor, Axle and wheel mount (aluminum or 3d printed)

-Rubber Tracks

The frame of the robot is similar to the first robot, an aluminum mounting affixes the motors and the wheel mechanism to the frame. Whilst the vacuum generator is bolted to the frame. The vacuum generator extracts air from below the robot and a flexible suction cup seals the irregular surface. Negative pressure in the space between the suction cup and the surface attaches the wall climbing robot to vertical and horizontal surfaces. In order to give the robot mobility on double curved surfaces, The suction cup should be adjusted to be lower than the tracks ( approximately 3mm). The frame of the robot should be as rigid as possible and the suction cup should be as soft and malleable as possible. There are other solutions to allow the wheels/tracks to always maintain traction, such as using a suspension system but we found this to be the simplest and most reliable.

The force of the vacuum generator must overcome the weight of the robot. Moreover the power/torque of the motors must overcome the overall weight of the robot, plus friction between the suction cup and the surface. Rubber-like materials produce friction with other surfaces, especially when a force is applied. We experimented with many solutions looking for a rubber-like material or coating to reduce the friction. An alternative solution was found by applying one or two layers of silver duct tape onto the suction cup. We found that this significantly reduces the friction and proving more durable than plastic coatings or lubricant. In practice the tape coating would slowly degrade, however it was easily reparable.

For certain curvature(single curvature or double curvature) the size of the wheel, the distance of the wheels are smaller the better, the weight of the robot should be as light as possible, bigger suction cup gives better suction force. So there is a balance between the weight of the robot and the power of the motors, suction cup size, and robot size.

<p><em>&quot;Small Robots&quot;?!?</em></p><p>They really are tiny (compared to earth) :)</p>
<p>What is the material that you are using?</p>
<p>Brilliant work! I was hoping it was a more general print bot than the three separate specialized bots, but specialized bots could also be added to accomplish other tasks of construction such as plumbing and conduits for electrical systems. A small &quot;pipebot&quot; could make structural tubing around itself, possibly with a second print head for a rigid foam core. Coordinated little pipebots could make honeycomb cell structures for strength. A fiber placer could also be rigged to insert fibers that stick through and up out of the bead allowing higher strength before the need of the vacuum bot.</p><p>Man does this have my gears turning.</p><p>Thanks!</p>
<p>Brilliant rethinking of 3d printing for large structures!</p><p>The flexibility of these robot's capabilities seem like they would be very impressive, but I find myself wondering if a much cheaper and simpler version could be designed to create simplified housing for disaster areas and other low income communities. I imagine something with a shape like a beehive sort of like the domes created by spirally winding continuous sandbags like these:</p><p><a href="http://www.earthbagbuilding.com/projects/smalldomes.htm" rel="nofollow">http://www.earthbagbuilding.com/projects/smalldome...</a></p><p>The device would not even need much in the way of computing power. The extruder could be guided mechanically, Sort of like this:</p><p><a href="http://jimsoven.blogspot.com/p/the-dome-part-i.html" rel="nofollow">http://jimsoven.blogspot.com/p/the-dome-part-i.htm...</a></p><p></p><p>Of course for this purpose using local materials would be best, but if the polymer/marble dust is cheap enough it would still be practical.</p>
<p>Is this thing DIY? Are there plans available?</p><p>Maybe there is a link here, but I don't see it.</p>
<p>I would like to suggest that, rather than using suction to hold the third (suction) robot in place, you take advantage of the inherent complexity of the structures that the grip robot can lay down, and have it &quot;build in&quot; a track for the suction robot to hold onto and follow. For instance, the grip robot could make a small series of indentations beginning every 0.2 meters horizontally and continuing throughout that horizontal layer. Then it would create an overhang in subsequent horizontal layers. The third (suction) robot would have notched wheels that would fit into this track, holding it to the surface. This would eliminate the need for a complex, failure-prone suction system, and also provide a built-in self-metering (measuring) system that would improve position accuracy. If I'm not being clear please contact me and I'll make a diagram. </p>
<p>that must be quite expensive!! how long did that take?</p>
My brain just melted. Really quite awesome.
This is by far the most incredible and amazing thing ever to come out of instructables. This is so inspiring.
<p>How much for a boat? great ible!</p>
<p>This is really cool. Basically a six-axis 3D printer. I want one.</p>
absolutely awesome! 3D printed house anyone!??
<p>Oh yeah.</p><p>Waste-free construction is the future!</p>
<p>Amazing work. Thank you.<br>And now for something that will make you laugh.</p><p>Your incredible project reminded me of part of a 1974 movie (not very good, except in parts) called The Groove Tube. <br>The part you have to see is this <br><iframe allowfullscreen="" frameborder="0" height="281" src="//www.youtube.com/embed/008BPUdQ1XA" width="500"></iframe></p>
<p>I take it the building material doesn't shrink much, or cracks might form. Rebar, or mesh, or some sort of fiber worked into the material is the usual solution in cement construction. This appears to have none. Do you ever wish it had some back-up fiber worked into the form?</p><p>A really nice instructable. Thanks. </p>
<p>Awesome, but please edit the audio so the &quot;music&quot; is 1/2 the volume. The people speaking have accents (to English speakers) and the obnoxious volume smothers their voices. And those of us who find this amazing would prefer to hear them, not the electronic buzz behind them. </p><p>loved it, I often thought what a hoot it would be to connect a pump/feeder to a fast set plaster/cement kinda like spray on cement. As I have no ability to make that I love that someone else did. </p><p>Bravissimo</p>
<p>I love your 1st paragraph :</p><p>There has always been a close relationship between architecture and technology. However, recently architecture has stagnated and the construction industry has been slow to adopt technologies that are already well established in other fields. Whilst we design digitally we still construct manually.</p><p>Thanks for sharing</p>
That is extremely cool. Except for one picture in which the device is being pushed by someone, it is very hard to understand the size of the objects. A human operator perhaps for proportion in the images?<br>A time lapse video of this project will win the interwebz :)
<p>Just saw the video which was not visible in the instructable app. The process is well thought of and the robots work well. I especially liked the third one which sticks with suction.</p>
<p>Wow, amazing!</p>
<p>I remember seeing this project elsewhere online a while ago. Thanks for posting to Instructables! I love this idea.</p>
<p>Wow, wow, wow... Absolutely amazing. 3d printers are the new future of buildings ,architectures, engineering, industrial, design and art.</p><p>Try contact with NASA, they are working with private corporations on giant 3d printers to settle bases and buildings on planets.</p>
Impressive! And everybody keeps complaining about the ever too small max sizes that 3D printers can spill out. :)
<p>This is so innovative and cool! I'd never thought that tiny 3d printers could be so capable at printing anything bigger than them... Nice job, thanks for sharing!</p>
this is really cool. it's amazing to see everything these 3d printers can do

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