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I am new to the RepRap scene, having attended a Makerbot workshop at Site3 coLaboratory, in Toronto, on June 9, 2011.

I am very interested to learn about machine-parts manufacture in microgravity environments, for a general purpose orbital factory, especially using selective laser sintering, of common ceramics and metals (eg: pyroxenes, iron, nickel, which not-only are very common on earth, but represent the bulk of material making up most asteroids). Making spacecraft parts from materials found in space would seem to be a really good idea, because lift-costs from earth are so high.

I find the goal of a fully replicable machine very compelling, and am keen to discuss ideas for printed electronics, replicable motors, actuators, sensors, and power supplies. Curiously, printed motors appear to be ideal for servo application.

Some day, in the perhaps not-too-distant future, RepRap will be brought to nano scale. At that scale, parts nearly always exhibit self-assembly. Research appears to be advancing on multiple fronts: a lock-and-key model of the parts, so that the right parts always fit together in exactly the right way; a process of shape change as the parts come together; nano-scaffold, to grow parts onto larger structures; and designer-enzymes.

If you happened to be in Stockholm on June 19-23, 2011, at the 12th conference of the european ceramic society, please tell me how this went.

I would like to know about GPL/creative commons licensed parts that will fit Lego and K'Nex construction blocks, as well as interconnect on several scales, from mm size to metre size. i.e: you can lay down a large block, and place a row of smaller blocks on it, and another still-smaller row on those, etc.


Many metal ores exist in space and may be refined there. US Patent database has several methods for lunar refining of construction materials, for making bricks or bars; one of the more-economical processes uses hydrogen, which combines with the oxygen in the ores and comes off as steam. The steam would then be split, by electrolysis, the hydrogen recycled, and the oxygen stored; this process would work as well on asteroids or on Mars, given a convenient source of water.

Silicon is one of the most common elements in the earth's crust and in space. It occurs naturally in the form of various metal silicates (quartz, pyroxenes, feldspar). Metallurgical grade silicon (mg-Si) is about 98% pure, and may be made by heating sand with carbon, to a temperature of 1900C. The reaction is SiO2 + 2 C --> Si + 2 CO. Upgrading mg-Si to 99.999+% makes it sufficient quality for solar photovoltaic cells. This can be accomplished cheaply by several methods, which are slowly reducing the price of solar grade silicon (sg-Si). Presently the cost of silicon in solar cell production accounts for about 30% of the total cost. Recent drops in price of raw material has enabled photovoltaic systems to be made for about $1/watt. As of June 2011, spot prices of sg-Si fell from avg $78/kg to $53/kg. I expect further drops in price, as new facilities come online.

some teaser links