Welcome! Log In Create A New Profile

Advanced

Interest in environmental projects like "Ocean Cleanup" and more?

Posted by VDX 
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 02, 2018 03:19AM
... locally available "raw materials" for compost or soil are -- seaweed, algae, plankton, fish, ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 02, 2018 03:46AM
There was a program on in the UK the other night talking about the issue but cant find that to post so post this instead
[www.youtube.com] just about the bad bacteria.

Google earth underwater [youtu.be]

Edited 1 time(s). Last edit at 10/02/2018 03:54AM by MechaBits.
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 03, 2018 01:57AM
That's another problem: most of the plastic material drifting in the sea has an equal or higher density than water. It sinks down, until the density is the same.
How would you make such plastic float?
You can't just press a brick off it...and making reliably airtight containers from a mix of plastics is a 'wet dream' in a double sense of meaning.
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 03, 2018 05:24AM
... for the material "drifting" under water -- an idea with a swarm of simple micro-submarines and "swimm-bladders" from the #6th post:

Quote

"I've asked you for some ideas about developing the software for a sort of \"swarm-bot ecology\" -- autonomous flying drones, rafts, ships, submarines and \"micro-submarines\", only capable of short travels, enough to start from a \"base\" (raft, ship or submarine), find and clamp to a piece of garbage ... and then start to float a \"swim bladder\" to rise the \"prey\" to the surface, were it can be collected conventionally (and tried to retrieve the micro-submarines)."

Bring them back to the surface, then it can be collected "conventionally".



For the "floating islands" -- you don't have to make the complete body water-tight! - simply mix the material with some air-filled bubbles, so the average density is slightly lower than water.

The floating structures shouldn't swim "on top" of the water - it would be sufficient, if only 3-5% of the body is above the surface -- so it would dampen waves ... and (big) enough load-bearing capacity to support buildings or soil with plants and trees.

Another idea is to design the submerged part to "breed" corals and reef biotopes ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 03, 2018 04:40PM
... transscription of an interesting conversation from the German forum:

*********************************************
[wersy]:

Flexible dock "The Dock" from 3:50
[www.youtube.com]

*********************************************
[VDX]:

... yes, I imagine something like that for the energy generation from the wave-stroke.

For the actual "load-bearing structures" then rather something 10x to 100x larger and higher (and 1000x to 1Million x more mass) -- then it even won't "notices" the wave winking smiley

The "floating islands" should also survive "Kawentsmänner" (monster waves), hurricanes and tsunamis cool smiley

*********************************************
[wersy]:

Quote
VDX
then it even won't "notices" the wave winking smiley

As long as nothing is in the way of a wave, it does not "notice" it.
If it encounters an obstacle, it is hindered and its energy is suddenly discharged.

Pressures of 100 t per square meter can occur.
A tidy amount, for the interpretation...

[www.t-online.de] waves-the giants-of-the-sea.html

Greetings Michael

And yes, a monster wave likes to come with 100 km/h.

*********************************************
[VDX]:

... I had already written something about it before - with really large structures you need "hardened" breakwaters in front of them, so that the built-up areas only have to do with waves a few meters high.

There's a lot more - e.g. "labyrinth structures" to "divide" the wave fronts and let them run out in side channels ... or deep (>100m) horizontal "wedges", like a beach in front with breakwater structures in random grids on top, so that the waves can distribute themselves on them and can dissipate their energy ...

*********************************************
[wersy]:

Quote
VDX
There is a lot more - e.g. "labyrinth structures" to "divide" the wave fronts and let them run out in side channels ... or deep (>100m) horizontal "wedges", like a beach in front of it with breakwater structures in random grids on top, so that the waves can distribute themselves on them and can decompose their energy ...

Well, there's a lot of stuff coming together.
Suppose the island is 1000 x 1000 m large.
That makes 4000 m of coast.
4000 m x 100 m deep breakwater makes 400,000 square meters of stable breakwater - which also has to swim.

It's a lot of work before there's even a single house.

Or have I miscalculated?

*********************************************
[VDX]:

... that will work out -- but it would only be the beginning.

If that should go in that direction, then the beginning is done with ships, which start to build smaller "floating bodies" of a few 10 to 100m in size and to connect them to "rafts" -- these would still go along with the waves.

Then more and more should be built around it and on top of it, until it reaches the area of the "inert mass", where the waves break on it or can simply "evaporate" over it or under it.

There could also be interesting something like a multi-layer structure with thick, flat floating and supporting bodies on "columns" - the massive (submerged) buoyancy bodies below the surface carry the superstructure, which itself sits on a "forest" of columnar elements, between which the waves break and distribute passing waves -- this could then also be used to generate energy by current or wave lift.

In time, "small" and "medium" rafts in sizes up to a few hundred meters could grow up, as well as "large" parts up to many kilometers in size, which either float freely in the "Studeln", or are anchored or even "set" on smaller islands or submarine mountain ridges and could thus be a stable island up to "mainland".

There's enough material/mass for that - after all, there should be more than 150 million tons of garbage in the 5 to 6 "garbage strudels" in between ... and many more have already sunk to the seabed.

And should this really go in the direction of "sustainable management" with permanent residents, I don't see any fundamental problems in converting the salts dissolved in the sea water back into metals and ceramics by evaporation and electrolysis -- with the carbon obtained from the plastic (key points: graphene, carbon-nanotubes, diamond, ...) and the biologically cultivated resources, a permanent self-sufficiency and even "export" (or trade) to the mainland would also be conceivable. winking smiley

*********************************************
[VDX]:

... oh, by "100m depth" I meant not vertical, but horizontal (WxHxD=width x height x depth) -- imagine this as a kind of "plate edge" - a thicker base of the island and around it a wedge-shaped ring structure at the height of the surface with coarsely structured "beach" areas rising down and up towards the centre of the island to "break" and "run out" of oversized waves.

In normal weather this could be used as a beach/coast ... in case of storm warning or forewarning of a monster wave or tsunami, then just evacuate/seal off/"harden" the endangered area as fast as possible ...

*********************************************


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 04, 2018 12:50AM
I thought the garbage collects in the middle of the Ocean, where wind and waves are calm or moddest? The island would tend to rotate with the current, but it's super slow ( rotation maybe helps growing crop? )
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 04, 2018 04:06AM
... this discussion was mainly for monster and tsunami waves, which too can occure in the middle of the ceans ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 05, 2018 06:56AM
... here is a project to build "floating cities" on the sea - [www.seasteading.org]

In the picture gallery there is also one which shows a "wave buffer" around it:




And for the floating/submerged bases -- there is already a lot of experience with floating concrete foundations in Holland - [www.daserste.de]

(transscripted) Quote:

In addition, the foundation is as stable as concrete, but has only 40 percent of the density of water:
"A new, floating construction made of polystyrene and concrete," explains Bart Roeffen.
"It consists of several layers: The lowest layer is made entirely of polystyrene, and several polystyrene blocks lie above it.
The gaps are then filled with concrete. Together this results in a very stable material that is unsinkable."
[/code]

Instead of polystyrene I would use hollow glass balls, because during abrasion/shredding they practically crumble into sand instead of microplastic.

I have some "liters" of micro hollow glass balls, as they are produced for various technical applications by the ton - the stuff is fluid-like ("splashes" around in the canister, like milk in slow motion) and hardly heavier than polystyrene.

Instead of concrete, better use "inertly" transformed garbage, seaweed/plant fibres, coral-lime (which are themselves "cultivated") and lignin as binders ... or also other materials and binding technologies that might develop over time - I think that at some point extremely stable carbon fibers can be produced in kilometres from plastic waste and woven into mats, from which extremely light but super-stable "mega" structures can be assembled (e.g. sewn!).

First estimates for the carbon nanotubes, from which such fibres could be "spun", have shown that they would be about 5x stiffer and about 2000x more tear-resistant than steel!!

Thin boards made of such fibres (woven or felted) are much lighter than water, but practically "bulletproof" and can hardly be damaged by normal means.

Skyscrapers made of it could have walls only millimeters thick, which would nevertheless have much higher stability and load-bearing capacity than today's steel/concrete/glass buildings ... and that with only a few percent of the weight of conventional building materials ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 05, 2018 12:21PM
I was saving all my glass coffee jars, as i wanted to build something with them, a room divider or something...ideally a big house..but I dont have enough...and it was getting ridiculous so I had to let a few go...but I kept some with seal and most of the cube/rectangle ones, i'm using a few as shelf supports. Would be a good project to make a bigger construction with them, stop them getting smashed up, and as we have paid for them seems a shame to give away.
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 06, 2018 01:52AM
It would be great to find a method which produces Carbon from CO2. Preferably an exotherm reaction which needs no additional energy except for the start.
Or extract the Carbon from a reaction between plastic, CO2 and saltwater. Abracadabra, there's something useful like sweetwater and fertilizer coming out off the exhaust. ( If only I took more lessons in chemistry... )

Edited 1 time(s). Last edit at 10/06/2018 01:53AM by o_lampe.
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 06, 2018 01:58AM
In the picture above, how would they keep the wave crasher ring from drifting towards the island?
They could use a spiderweb structure to stabilize it.
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 06, 2018 04:11AM
... "spiderwebs" (made of super-strong carbon fibers winking smiley ) to fix them realtive ... or underwater-drives -- maybe the "Lamellar drives" I've mentioned previously - slow oszillating horizontal plates on the undersides, with skewed, merely elastic lamellas in the water, which works like "gigantic" cilia ... did this with parts in size of some ten centimeters, but it's much more efective, if bigger winking smiley


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 20, 2018 11:57AM
Those crazy Canadians puffed away all their weed in a few days! smoking smiley
That gave me an idea how to fund a project like the floating plastic kontinent. Just use it to plant weed. A small island at the Californian coast will do for starters winking smiley
Plenty of sun there and legal when you stay out off the 3-mile zone.
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 20, 2018 03:48PM
smoking smiley


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 24, 2018 05:47PM
... transscription from the German forum:

##################################################################

... because my sister is thinking about writing a little "experience story" about the topic (she does it occasionally for a "Medieval"-magazine), I have compiled the essential points and ideas for her again.

Here the first draft of the "Ideas-Collection" with some of the more interesting concepts roughly summarized:

*****************************************************************************
Thoughts on the project "Floating islands in the garbage continents".

Status: - in all oceans of the world "garbage whirlpools" have formed, in which huge quantities of floating garbage accumulate due to the ocean currents.
The largest are located in the Pacific - here there are two "garbage vortices", one in the direction of Australia, one in the direction of South America.
The "size" of the largest would roughly correspond to the extent of Central Europe, i.e. over 1000 kilometres in diameter!
The current amount of waste in the oceans is estimated at about 150 million tons, but this could still be far understated ...


********************************************
Collection of ideas from other projects:
- collecting floating garbage on the surface, creating it on land and separating it and recycling it (project "The Ocen Clean-up" does this as a test)
Criticism: only floating garbage on the surface, ways to and from the country take very long

- Stop waste discharge from rivers into the seas - is already being tackled by some countries, most still superior or do nothing at all

- Fishing boats should not dump the "garbage by-catch" in the nets back into the sea, but collect it separately and hand it in for a "deposit" in the harbours - some of them already go out only for the "garbage" ...

- Various project to clean up the sea coasts ...

- Dutch build floating platforms for houses and greenhouses instead of building higher dams to protect the coastal areas from rising sea levels -- works only in river mouths and in protected coastal areas, not on the open sea (storm and too high waves)

- Project "Seasteading" wants to build "floating cities" in harbours and "quiet" coastal areas - "ring walls" as protection against waves, only conditionally "seaworthy" -- initially only planned as "sea domiciles" for rich and super-rich ...


*****************************************************************************
Difference of the project "Floating islands in the garbage continents"
- first of all, large ships (discarded container ships and freighters, which are currently available at the "scrap price" because commercial shipping has collapsed) are to be used as "bases" with plants and machinery for plastic recycling and "charring", as well as equipment and facilities for large-scale construction with sufficiently large crews for a long-term/"permanent" stay to the "garbage continents", and on site (without long arrival/departure times) begin to build large/thick floating structures.

- From these large/thick (several tens to a hundred meters in size, several tens of meters in thickness/height) elements, even larger "rafts" are then to be assembled, which, due to their size/mass and stability, can themselves withstand storms and waves up to a height of more than 30m, and which, in combination, are also to serve as "breakwaters" for structures built further inside.

- these "base" elements should not be built like ships with walls and cavities, but rather as massive bodies with many small cavities for buoyancy - it is ideal if they are so heavy and have so much buoyancy that they float e.g. at a size of 100x100 meters and 50 meters thickness half (or more) in the water and half (or less) above it - on top of this more "sensitive" structures such as houses can be built.

- as building material all possible stable solid bodies are suitable, which in turn do not give off any plastic when crushed over time (sun, waves, collisions, ...) - e.g. stones, sand, (sand). Stones, sand, (coral) lime, plant/tang fibre, glass fibre, metal wires and rods (for connection/tensioning), glass hollow spheres (for buoyancy), solid material extracted from the plastic waste and chemically converted (inert) such as coal ...
Plant resins - e.g. lignin, which is currently a waste product in paper manufacturing and could later also be obtained from trees/plants and tan/seagrass planted on/around the islands - are suitable as binders to combine this into a stable, concrete-like mass (see e.g. polymer concrete for highly stable industrial plants, which is made up of sand, gravel and cast resin/polymer).

- over time, marine biotopes (coral reefs, etc.) will also form around the islands, or should also be created themselves (e.g. as a raw material source for coral limestone or fish for food supply).

- Energy production on site by sun, wind, waves, current, temperature differences, evaporation, ...

- with sufficient energy more than enough drinking water can be obtained from the sea water - but also salt and from the salt practically all known materials/chemicals of the chemical elements dissolved in the sea water, which can be extracted and separated e.g. by chemical/galvanic processes ...

- on these first "rafts" even more stable material can be "built up" over time in order to extend them to "real" floating islands with enough mass/carrying capacity and size for a permanent planting with trees and plants (also for food supply).
Over time, this could also allow "floating continents" with a diverse structure with coast/inside areas and also large inland freshwater lakes or saltwater inland seas (down to the ocean open or filtered).

- for the garbage drifting in the sea, below the surface (or already sunk on the ground), methods for collecting have to be developed - in the beginning with ships/rafts as "supply bases" an armada of smaller (autonomous) boats, drones and submarines has to be built, from which even smaller submarine threats launch and expose "micro-drones" near underwater garbage whose only task is to "cling" to the garbage and inflate "swim bladders" with which the garbage drifts to the surface and can be conventionally collected there...


*************************
Political implications:
- Artificial islands" outside the 200-kilometer EEZ areas around the coastlines are located in a "lawless" space where only maritime and international law still applies - so completely independent rules and legal structures or even "nationalities" can emerge on them!

- This would also be an opportunity to offer alternative housing to the currently "sinking" micro-nations that inhabit small islands that will be flooded by rising sea levels within the next decades -- currently several of these micro-nations have already started negotiations with other countries to accommodate their populations there.

- because of this "lawless" environment one has to think about the protection of the islands against e.g. pirates or attacks of other nations - in the beginning this would be done with mercenaries/protection troops and contracts with countries on the nearer mainland or neighbouring "islands" - later this should be regulated by the own population in the form of volunteers or also "conscription" ...


*****************************************************************************
Ideas for implementation and for the "start", step-by-step expansion:
- Make idea known, win supporters, donations and active members
- Assemble equipment - ships, life support/supply/energy, plastics processing/recycling/carbonisation, building materials and equipment, ...
- Start projects" with smaller ships near the coast over a few weeks/months as pre-exercise and "show-case" for the interested parties and media
- Long-term projects" with volunteers over several months/years with larger ships and construction teams/facilities directly in the "garbage maelstrom".
- Building ever larger "rafts" to demonstrate seaworthiness and long-term stability and to increase the processing capacity for the collected waste.
- Creation of the first "self-sufficient" raft/island structures with production of energy, food and building materials on site
- ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 25, 2018 12:52AM
An island made of garbage for rich and super-rich people? C'mon, think again.
They rather buy a yacht and anchor in Monaco than living on a island without international airport. (btw: would it be possible to land a passenger-airplane on such island?)
As I wrote before: It's the lawless community like drug syndicates who'd invest in offshore plantages.

Interesting point to pay fishers for by-catched garbage. Especially the stuff floating sub-surface or near ground.
But I think politicians will complain it's not 'their' waste and try to blame other countries. It'll take 20 years or more until they'll find a worldwide agreement.
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 25, 2018 02:41AM
... no, the "seasteading" project wouldn't build their "floating cities" from garbage, but from concrete, metal, glass and plastic eye rolling smiley

Look into their renders - [www.seasteading.org]

[www.seasteading.org]

[www.blue-frontiers.com]

Edited 1 time(s). Last edit at 10/25/2018 02:42AM by VDX.


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
October 26, 2018 02:14PM
... transscription from the German forum:

##################################################################


... in order to continue the discussion here a little bit, I will quote myself from another forum, where we are talking about the "duties" of the politicians/representatives of the people:


************************************
... the problem with the higher politicians or "elected representatives of the people" is of a somewhat different nature - they simply have no sense for genuine long-term considerations.

For most, the "time horizon" is rather limited to the current legislative period ... and only with sufficient prospects of a re-election also on the next ... from then on it becomes less and less interesting for them.

What looks like a "longer-term planning" is mostly only a direct reaction to current opinion trends and forecasts, which are made by consultants, who are involved or obliged somehow.

For a real "generation project" this has to be approached completely differently - this is also one of the "ulterior motives" in the construction (and "settlement") of artificial islands outside the spheres of sovereignty of the individual countries (or more than 200km away from the coasts).
There one can/must organize oneself and build up something like a "state structure" -- and not only one! - with increasing number of the "islands" several quite differently oriented groups and/or "island nations" might develop ... some more successful, others less or also not ...

And who knows - with the differently positioned and motivated "world views" on the different "islands", this would also be a possibility to try out different social structures and, if successful, to develop them further or to be adopted by others as a "good example" ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
November 17, 2018 04:14AM
... a few more thoughts on the faster establishment and expansion of the "mega-structures" and on sustainability:

- instead of a massive basic body made of already "converted" or almost completely reduced to coal collected garbage, only a massive "shell" with a few meters thickness and inside with many cavities and access ways should be built.

- These cavities are then only filled with the material collected from the sea (preferably already sorted) - this is actually an enormously valuable raw material when we have developed "large-volume molecular technologies" with which the plastic and the other components of the "garbage" can be broken down directly into the basic molecules and processed.

- In order to get to the cavities quickly and efficiently, sloping and spiral ramp tunnels with sufficient width/height for vehicles should run through the island base - so material can be moved from and to the respective destinations at any time.

This would allow large floating bodies to be built up relatively quickly, which would then be gradually built up to their full size/thickness with the material collected and only partially "converted" for the building substance.

I imagine that the "bodies" of the floating islands consist of a kind of "amber" with sand, coal and supporting fibres in thicknesses of a few to several tens of meters and many isolated (partly completely "dense", partly accessible) hollow lumen inside - similar to our "small" 3D-printed parts with a "shell" and a hollow honeycomb filling.

On the one hand this is enormously stable, but decays over time, e.g. in collisions or crumbling due to aging by sun and waves, but only into the relatively harmless particles from which the "shell" was built ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
VDX
Re: Interest in environmental projects like "Ocean Cleanup" and more?
December 03, 2018 04:11AM
*** transscription from German ***

... a few thoughts on the current climate protection conference in Poland:

The way I see it, the countries probably won't "put themselves into it" so strongly and fast that they will manage the "max.+2°C or +1.5°C warming of the world climate until 2100" eye rolling smiley

The first negative effects could already come with the recent increase in droughts, floods and forest fires -- but they are far from sufficient to trigger a general rethink and "serious" actions sad smiley

I wonder whether there is a "Plan B" which should take effect if all this does not help and the oceans rise much faster and stronger?

Even the large-scale effects of more and more frequent droughts/floods and erroneous harvests or a dramatic increase in "local" storm catastrophes (heavy rainfall, forest fires, wind breakage, crop failures, ...) are not really foreseeable - the only thing I can see so far is that insurers are preparing for higher insurance premiums eye popping smiley

Perhaps the ideas for building such huge "mega-structures" from the waste drifting in the seas should not only be focused on the distance, on the open sea, but should also be considered whether this could already bring something for our local problems on the mainland?

I'm thinking of a massive "redesign" of streams and rivers as well as hill formations, in order to channel or buffer the flow of water in the case of more and more frequent stagnant rainfall without damaging the environment (á la "artificial beaver dams"), which could also serve as a water reservoir in the case of a drought phase ... but on the other hand also to place "wind catchers" in the landscape in order to buffer the likewise increasing strong winds and tornadoes ...

I still remember what I heard and read from the German settlers 100 to 200 years ago about the "cultivation" of the huge swampy or steppe-like (flat) landscape areas in Western Russia.

In order to make swampy areas arable, they have transformed huge swampy areas into fertile farmland with drainage systems made of underground clay pipes - after the Germans were deported and the Russian farmers tore the drainage pipes out of the ground with their deeper ploughs, a lot has become marshy again.

In the drier steppe areas, where it rarely rains in summer, they had laid out parcel fields with bush hedges and trees in between, which had "intercepted" the snow in winter, which then melted in spring and watered the soil in this way - before and shortly after 1900 these were the "granaries of the world"!

After the Russian "large-field economy" with continuous fields up to and above the horizon was introduced here, too, and the hedges and trees were removed for this purpose, they now also had frequent crop failures due to drought or massive efforts for artificial irrigation (diverted rivers and drained huge lakes!) ... and the wind now also blows away the fertile humus soil and "sands" rivers and lakes in the direction of the wind.

If something like this could be done with the (200 years ago) possibilities of that time -- then why not rethink in this direction today?


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Sorry, only registered users may post in this forum.

Click here to login