FulanoDetail
Sources:Carbon fiber reinforced polymer and tensegrity structures in search of model architectural and engineering solutions Chain-based lattice printing for efficient robotically-assembled structures | Communications Engineering
Sources: Ultralight Cellular Composite Materials with Architected Geometrical Structure Interlocking Assembled 3D Auxetic Cellular Structure
Sources: Long-fiber reinforced thermoplastic composite lattice structures: Fabrication and compressive properties [PDF] SANDWICH PANELS WITH CELLULAR CORES MADE OF FOLDED COMPOSITE MATERIAL : MECHANICAL BEHAVIOUR AND IMPACT PERFORMANCE | Semantic Scholar
Sources: Investigation of impact resistance performance of pyramid lattice sandwich structure based on SPH-FEM [PDF] Mechanical properties of carbon fiber composite octet-truss lattice structures | Semantic Scholar
Sources: Assembled Composite Lattice Structures: Towards Ideal Performance in Large-Scale Applications Properties of 3D Double‐Arrow Negative Poisson’s Ratio Lattice Structure under Quasi‐Static Compression and Low‐Speed Impact - Sun - 2022
Sources: Mechanical properties of modular assembled composite lattice architecture - ScienceDirect Mechanical response of Ti–6Al–4V octet-truss lattice structures - ScienceDirect
Sources: Toward Cost-Effective Timber Shell Structures through the Integration of Computational Design, Digital Fabrication, and Mechanical Integral ‘Half-Lap’ Joints Static and dynamic compressive behaviour of 3D printed auxetic lattice reinforced ultra-high performance concrete
Source: Fabrication and mechanical properties of three-dimensional enhanced lattice truss sandwich structures Mechanical Performance of Three-Dimensional Printed Lattice Structures: Assembled Versus Direct Print - PubMed
Modular Structures | Eike Schling
Also, there is the possibility of using woven trusses with a japanese technique called “Kagome”. But I have no idea how I would realistically make them in bulk by myself.
Observation:
I don’t think they built it by hand, but using a machine:
A weaving machine for three-dimensional Kagome reinforcements
In this one (that I already listed, but didn’t take a proper look at it), they take a bunch of metal wires, twists them until they spiral, separate then and finally assembly them in the way they want:
Wire-woven bulk Kagome truss cores
Sources: Ultralight shape memory actuator from wire-woven Kagome truss - ScienceDirect The compressive response of new composite truss cores
Sources: Wire-woven bulk Kagome truss cores - ScienceDirect Permeability measurements and modeling of topology-optimized metallic 3-D woven lattices
Sources: New Cellular Metals with Enhanced Energy Absorption: Wire-Woven Bulk Kagome (WBK)-Metal Hollow Sphere (MHS) Hybrids† Hybrid Nanocrystalline Mesoscale Periodic Cellular Materials
There is also the possibility of using the filament winding composite method to make entire pieces by using a rotating mandrel.
Sources: Anisogrid thermoplastic composite lattice structure by innovative out-of-autoclave process | The International Journal of Advanced Manufacturing Technology https://sci-hub.ru/https://link.springer.com/article/10.1007/s00170-020-05671-6 Russia Creating Advanced Mesh-Framed Composite Wing
Sources: EPA backs IsoTruss carbon fiber concrete reinforcement research In-Plane Compression Properties of Continuous Carbon-Fiber-Reinforced Composite Hybrid Lattice Structures by Additive Manufacturing
Sources: Arris Wins GOOD DESIGN Award for Optimized Composite Structures | Business Wire An efficient and scalable manufacturing method for CFRP lattice structures for satellite central tube and large deployable antenna boom applications | CEAS Space Journal
Sources: (PDF) Application of Lattice Composite Structures as Reinforcing Elements of Concrete Columns https://pt.slideshare.net/slideshow/the-mechanical-properties-of-composite-lattice-structures/142452717#23
Sources: (PDF) Isogeometric sizing and shape optimization of 3D beams and lattice structures at large deformations Extension of Computational Co-Design Methods for Modular, Prefabricated Composite Building Components Using Bio-Based Material Systems
development of mass and cost efficient grid-stiffened and lattice
A parametric study on compressive characteristics of Wire-woven bulk Kagome truss cores
(PDF) Developing Unit Cell Design Guidelines for Meso-scale Periodic Cellular Materials
Sandwich Plates Actuated by a Kagome Planar Truss
Design and fabrication of carbon fiber lattices using 3D weaving | Scientific Reports
Effective thermal conductivity of wire-woven bulk Kagome sandwich panels
FB06 - Adaptive modular interlocking connection
I also didn’t consider the possibility of using these strut/nodes where you can fit the tubes of the lattice/truss. But one thing is doing this for a building, another is doing it for a dynamic structure…
Deployable tubular bar structures with laterally confined flattened ends - ScienceDirect
https://pt.slideshare.net/slideshow/folded-plates-and-space-truss-structures/157475987#15
https://pt.slideshare.net/slideshow/5-space-framespdf/259323250
https://pt.slideshare.net/slideshow/space-frame-65559468/65559468#1
Lecture 14.5: Space Structure Systems
Design and analysis of the composite lattice frame of a spacecraft solar array
Design of dual-material lattice structures with compression-torsion bistability - ScienceDirect
How to make big things out of small pieces | MIT News
Design of composite lattice materials combined with fabrication approaches
Revolutionizing Aircraft Materials and Processes
https://www.tandfonline.com/doi/figure/10.1080/17452759.2022.2074698?scroll=top&needAccess=true
Using Kirigami to make Ultrastrong, Lightweight Structures - Tech Briefs
[PDF] Titanium alloy lattice truss structures | Semantic Scholar
(PDF) The compressive response of new composite truss cores
A new fabrication method for hierarchical truss materials with millimeter-scale struts
Topology design of general tensegrity with rigid bodies - ScienceDirect
(PDF) Material-Robot System for Assembly of Discrete Cellular Structures
Munich, Olympic Games Tent | Node of the structure. View fro… | Flickr
Systems and methods for joining space frame structures
Southern Shade | CEPT - Portfolio
Increasing load capacity of steel space trusses with end-flattened connections
[PDF] NEW EXPERIMENTAL RESULTS OF THE RESEARCH ON REINFORCED NODE IN SPACE TRUSS | Semantic Scholar
Characteristics of Prefabricated Spatial Frame Systems | Semantic Scholar
Bended panels - Grasshopper - McNeel Forum
PneuMesh: Pneumatic-driven Truss-based Shape Changing System
Experimental investigation of bending stiffness of a novel 54m FRP space truss string bridge
Investigating the redundancy of steel truss bridges composed of modular joints - ScienceDirect
(PDF) TYPES OF STEEL AND CONCRETE COMPOSITE CABLE SPACE FRAMES
Performance of Novel U-Connector in CFS Truss-to-Column Bolted Connection under Axial Force
(PDF) Flexural properties of lightweight FRP composite truss structures
Behavior of incrementally launched modular steel truss bridges - ScienceDirect
Space truss construction modeling based on on-orbit assembly motion feature - ScienceDirect
Steel Truss Structure: Revolutionizing Modern Architecture
BMW GINA Light Visionary Model Concept Car (Not space frame, but to this day I still wonder what is the system under the cloth)
Modular Truss-Z system for self-supporting skeletal free-form pedestrian networks - ScienceDirect
Multi-Objective Optimization of Spatially Truss Structures Based on Node Movement
Timber Structures for Large-Span Structures
I just couldn’t find any hybrid between space frames and monocoque structures…
ChatGPT suggested this articles, dunno if counts:
(PDF) Production of a Composite Monocoque Frame for a Formula SAE Racecar
Design and analysis of a composite monocoque for structural performance : a comprehensive approach
The Design and Analysis of Multiple Monocoque Chassis for Formula Student (FS)racecar
On the Use of Composite-Steel Joint for Semi-Monocoque Frame Design
This is the same technique used in interlocking laser cut parts, like those wood interlocking toys. Or even those tube toys that you interlock together…
How to make a 3D model in Cardboard | xTool S1 Laser Cutter
COMO LAMINAR MODELOS TRIDIMENSIONALES ft Ortur Laser Master 2 S2
How to make a 3D model with your laser a - complete video lesson
Joinery: Joints for Laser Cut Assemblies : 16 Steps (with Pictures) - Instructables
autoAssembler: Automatic Reconstruction of Laser-Cut 3D Models
Reconfigurable Interlocking Furniture
Creating laser cut 3D forms super easily
3D Printing Interlocking Parts: What Is It & How to Do?
How to Join Laser Cut Parts Without Fasteners | SendCutSend
Joinery: Joints for Laser Cut Assemblies : 16 Steps (with Pictures) - Instructables
CNC Panel Joinery Notebook - Make:
Craft Corner: Laser Cutting Pt. 2
Laser Cutting Basics : 15 Steps (with Pictures) - Instructables
Designing Laser Cut Joinery in Fusion 360
The advantages of laser cutting on welded joint production
Laser Eteched Pie Cuts w/ Interlocking Teeth 10 pcs - 9 Degree
Laser tube cutting for novices | TRUMPF
240 Tube laser ideas in 2024 | laser, metal working, metal sheet design
3D metal lattice structure manufacturing with continuous rods | Scientific Reports
A basic guide to laser cut joints.
FreeCAD Laser Cut Interlocking
Freecad For Lasers P1. 1 - Tabs and Slots
Is 'Laser' MDF worth the extra money?
Ultimate Guide to Laser Cut Boxes
How to Make Laser Cut Boxes with Finger Joints
Create Glue-less Interlocking Laser Cut Parts With Sketchup Slicemodeler : 8 Steps - Instructables
Full guidance of how to convert 3D model into slices for laser cutting - EnduranceLasers
Designing For Laser Cutting In SolidWorks: Step By Step
Printy Pipes - More Everything!
Printy Pipes - Construction Toy by 3d-printy - Thingiverse
https://br.pinterest.com/pin/536209899396824776/
https://br.pinterest.com/pin/10133167905352736/
GMU:I am a wild type/Projekte/Decaying shelters - Medien Wiki
https://br.pinterest.com/pin/211174968385615/
Sources: Node introduction of space frame structure Round Carbon Fiber Pultruded Tube Structures
(I also thought of using bolted hollow blocks/bricks, just like the nodes in the space frame, but I couldn’t find anything on the subject)
So, in the end, if all I need to do in order to build lattices and the like is to use these connector nodes (made out of whatever material) and connect tubes (made out of whatever material)...
Of course, they would need to be significantly smaller in order to make structural lattices.
Then why would I need to build anything in other, more complex manners?
This method could work for every type of material that I suggested: metals, polymers, fiberglass composites, bio-composites, bioplastics etc.
I think this is the design I will stick with.
Also, a few problems I thought:
- How do I check the integrity of the structure?
- How do I mass produce them on my own?
- How do I assemble the structure on my own without being like building a sand castle with tweezers?
In the end, you could use either option with either material.
On the Subject Of Energy Generation:
Although I went on my way of wasting time talking about a myriad of different engines, efficiencies, power densities, complexity etc. I never actually stopped to think about the cycles.
Only in the last Project Log I talked about the Carnot Cycle, and how the efficiency of Magnetohydrodynamic generators can’t be that much improved because of the thermodynamic properties of the Carnot Cycle.
Fuel cells, for example, like the Molten Carbonate Fuel Cell that I intend on building, are under the Nernst Equation, which I will call “Nernst Cycle”.
And that is one of the reasons why I detest ChatGPT and learning through youtube videos.
If I asked the same questions about this project to an actual Engineer at a university, he would probably point out at first about the thermodynamic cycles and list which ones are the most promising.
With ChatGPT, however, it only answered superficially about questions until I brought up the subject.
ChatGPT gave me a list of different cycles, but let’s remember that it is just throwing random numbers taken out of its virtual ass and listing commonly known cycles, not all cycles.
Plus: these are common efficiency ratings that were actually achieved, not the theoretical maximum.
Otto Cycle: 30-35>#/p###
You'll understand everything about Atkinson, Miller and Otto cycle engines after watching this video (I think this video may be relevant)
Diesel Cycle: 40-45>#/p###
Brayton Cycle: 30-40% (55-60% in combined cycles)
Stirling Cycle: 30-40% (up to 50% in experimental setups)
Ericsson Cycle: Theoretically up to 60-70>#/p###
Atkinson Cycle: 35-40>#/p###
Kalina Cycle: 45-55>#/p###
Lenoir Cycle: 10-20>#/p###
Seiliger/Sabathe Cycle: 35-45>#/p###
Organic Rankine Cycle: 10-30>#/p###
Carnot Cycle: 30-40>#/p###
Although the engine operating using combined cycles achieved the most efficiency, around 67>#b### it was the size of a building and used a combined cycle.
For other cycles that aren’t for heat engines or combustion engines:
Nernst Cycle (Fuel Cells): 60-80>#/p###
Betz Limit (Wind Turbines and Propellers): 35-45% (giant ones can reach 80%)
Photon-Driven Cycles (I could only find about photovoltaics): 20-25% in commercial use.
Magnetocaloric Cycle (just like the Carnot Engine, it can be used for either cooling, heating or generating power): ChatGPT said the maximum was 60%, but most of the machines built have less than 1% efficiency.
Thermoelectric Cycle (Seebeck and Peltier Effects): 5-8>#/p###
Quantum Heat Engines: 99% This is cool and all… If there was a Quantum Heat Engine bigger than 6 atoms. 🫠
Thermophotovoltaic (TPV) Cycle: 30-50% Needless to say, you need REALLY expensive materials to achieve such efficiency ratings. Like, literally using gold.
Piezoelectric Cycle: 5-20>#/p###
MHD Cycle (Magnetohydrodynamic Generators): 15>#/p###
Supercritical CO₂ Cycle: 30-40>#/p###
Allam power cycle: (supposedly) 60>#/p###
It seems like the Fuel Cell is still the best option I have… 😔
… Or not.
I do like the idea of using the reverse turbine/inside-out turbine/compression loaded turbine engine with heat exchanger coupled to an electric generator, since its structure is simple and can (supposedly) work with any kind of fuel, unlike the piston engine.
But it is really hard to tell from a purely hypothetical point of view (like this entire project so far), since turbine engines are normally built with extremely high precision and strong materials.
The turbine in question is this one:
Source: Benefits and Challenges of the Inside-Out Ceramic Turbine: An Experimental Assessment | Journal of Propulsion and Power (The article isn't available on sci-hub either, but you can see the pictures in google images)
Essentially, it is a bunch of ceramic blades stacked to a composite disc (of carbon fiber, but it can be made out of fiberglass just the same) that is attached to the axis of rotation of the engine. When the engine spins, since the carbon fiber is attached to it, it will suffer tensile stresses (which carbon fibers are better at resisting), but since the ceramic blades are on the interior of that carbon fiber disc/ring, they will suffer compression stress (which ceramics are better at resisting).
Think of it like those spinning space stations that simulate gravity.
(and yes, you would still need to add air-cooling vents through the ceramic turbine blades because of how hot they get)
I’m sorry for always going back on my ideas, but realistic speaking… I wanted this project to be as “DIYable” as possible and as cheap as possible without being insanely dangerous.
How could I (or anyone) easily DIY lithium carbonate, sodium carbonate and potassium carbonate? Even if you perfectly extracted 100% of lithium from AA batteries, they only have 1 gram. You can imagine the cost and danger of finding 1 kilogram of it.
Plus, lithium salts are also dangerous because they directly attack the human nervous system.
A turbine engine is still dangerous, but does it compare to a molten bath of acidic salts at 700ºC that can also destroy your nervous system if you inhale them?
I’d rather work with a Stirling engine, actually. But where will I find one that can output 300 to 350 kilowatts of power and fit in a backpack?
This one article has diagrams showing each stirling cylinder with units in meters (you will have to use sci-hub to see it):
Now I just found out about Helium heat turbine engines.
It is similar to supercritical CO2 steam engines, where the carbon dioxide gas is compressed until it becomes liquid. However, since it is helium, it can’t be turned into a liquid at room temperature. Unless you use an unpractical amount of pressure.
It is said to achieve around 50% to 60% efficiency by itself, with the catch that you need multiple stages in series doing the same thing.
It normally works at 100ºC to 900ºC and at pressures of 20 to 70 atmospheres.
But can I actually use these numbers as parameters? These are megawatt gigantic turbines, not backpack sized…
This is the closest thing to a Stirling Turbine Engine tho…
I genuinely don’t know how to continue…
This one is a nuclear reactor plant with a 125kg turbo generator with 60,000 rpm with an output of 370 kilowatts in total, the article says that it is around less than 5% of the total of the power plant. Meaning the entire power plant weighs at least 2500 kilograms.
I would risk saying that 1500 kilograms is at least the radiation shielding of the thing and the generator must be heavy because of the magnetic core of the slots and the permanent magnets… And the radiator…
I’m just coping?
This looks like a turbocharger… The turbine doesn’t seem that big, so does the generator, it is said that it has 0.11m³ of volume.
This would be a 1 meter long cylinder with around 40 cm of thickness.
After some deliberation, checking the possibilities and so on, I reached the conclusion that the molten lithium fuel cell is the only viable option. As much as I dislike it…
A turbine engine can explode since it compresses air to 40 to 60 atmospheres of pressure and reaches 1500ºC at the turbine inlet. The helium turbine needs to be at 20 to 70 atmospheres, and needs a gigantic radiator to work…
I actually went looking for 3D models of turbines and compressors, but most, if not all 3D models are just mockups that haven’t been designed with aerodynamics in mind. Some don’t even have a description telling you that and others may or may not be actually practical aerodynamic designs, but they are meant for really small applications.
So, since this is a really daunting task, I could literally spend months or even years designing turbine engines, just to take more months or years to build them just to find out they don’t work.
Either because the models weren’t made for this, or because my building skills were lacking.
On the subject of Haptic Suit:
Some time ago I talked about how you could simulate touch on the mech suit and on the pilot by using force sensors that could be inkjet printed on plastic or other surfaces.
The idea still stands, but I’d like to add some things.
IF you want to add very fine texture to the Haptics of your system (not necessarily mech), you can do the following:
You can use an array of ultrasonic sensors for that. Like in this video:
Distinguishing textures using the PapillArray tactile sensor
However, it is really not practical to use hundreds if not thousands of these for the whole body.
But you can use any sensor for that, such as using an array of light sensors with a flexible reflective surface. You could use DIY solar cells/photodiodes with a few LED’s. Like in the robot finger in these videos:
Tactilus Multi-Vector Sensor | Robotic Hand Gripping System
If you want to simulate humidity, you could follow this article. It uses air flow with a temperature changing device, but you could use something like a Peltier module that can either heat or cool based on the electric current you apply.
I also forgot that you could use light sources and a membrane to detect sound.
When a flexible membrane is isolating a cavity, like an air chamber, any sound (and thus, change in pressure) will oscillate the membrane.
If you attach a magnet and a hall sensor or a solenoid, these vibrations will be turned into electrical oscillations, which in turn, can be processed into sound (that is how your timpanus works btw, with exception of the electrical part).
You can replace the electromagnets with anything, such as lasers.
You could use two copper oxide photovoltaic cells (aka solar cell), where one is the receiver and the other is the emitter of light. When you add electricity to solar cells they start emitting light, normally in the form of infrared.
Then, all you need to do is add a reflective surface that can either vibrate or be deformed.
Why all solar panels are secretly LEDs (and all LEDs are secretly solar panels)
Sending Sound on a Laser! - The Science of Telecommunication with Mr. G - Part 3
Infrared light emitting transistors and solar panels
Microscopic Marvel in your Earbuds
Barometric pressure sensor: working principle
https://www.compadre.org/osp/EJSS/4503/288.htm
Smoke on the water -- and in the microphone?
Electrostatic Loudspeaker (ESL) Technology - MartinLogan
How To Build A Simple Carbon Microphone
On the subject of Actuators:
The reason I abandoned the idea of using dielectric elastomers is: that the amount of contraction strength is based on the amount of material in the dielectric (aka insulating) layer.
Ideally, you would have nanometers worth of electrode layers and dielectric layers.
But that is not practical to build, and quite difficult to achieve.
Personally, I’m quite frustrated with all the actuators that I suggested so far.
Electric motors can’t be predicted with my current knowledge, but I was wondering about the possibility of making artificial muscles using ferromagnetic plastics/resins/foams/fluids with solenoid coils.
The idea is that once the solenoid coil activates, the magnetic material will be attracted to it, simulating contraction.
Like a flexible voice coil actuator, a flexible solenoid or a flexible linear electromagnetic motor.
As always, predictably frustratingly, I can’t find any article with a similar idea so I can see if it works well or not.
Soft electromagnetic actuators - PMC
Sculpture with Magnets & Iron Powder - supermagnete
Magnetic effect on iron powder in resin
Magnetic Slime Swallowing Monster Magnets! TKOR's DIY Magnetic Slime Experiment!
Seeing magnetic fields with permanent, electromagnets and ferrofluid
How Ferrofluids Enhance Solenoid Actuators' Performance & Efficiency?
MAGNETIC PAINT | Cheaper and easier than Ferrofluid and Ferripaste?
Many of the articles talking about liquid metal soft actuators normally use galinstan in magnetorheological elastomers, but it is only one of many other low-melting point metals out there: Fusible alloy - Wikipedia
You could also do a bunch of concentric electromagnets in a similar way to how muscles are structured.
You can even make the liquid metal elastomer actuators like conventional dielectric elastomer actuators:
And that also entails its many, many methods of manufacturing DEAs:
I suggested all of this sh1t, but I always forget that elastomer actuators have efficiencies tied to their flexibility/elasticity. And the most flexible type of elastomers are like HASEL ones.
(just pretend these use electromagnets instead of electrostatic)
High-strain Peano-HASEL actuators
The coils don’t need to be made out of liquid metal, or be on the exterior of the actuator. It could be flat coils with flexible magnets (like one of those used on refrigerator doors) on the outside that compress the bags.
HAPSEA: Hydraulically Amplified Soft Electromagnetic Actuator for Haptics
Linette the Linear Actuator that Mimics Muscle
Magnetohydrodynamic levitation for high-performance flexible pumps | PNAS
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