An old-school solution to printing reprap electronics?
Posted by Sci
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An old-school solution to printing reprap electronics? February 02, 2010 08:16PM |
Using NASA's metal-depositing 3D printer as an example, printing metals in a vacuum removes the problem of metals oxidising when deposited.
But if you have a vacuum environment on hand already, it's also good for thermionic valves.
The idea of printing huge glass bulbs is right out of course, but valves didn't die off right away with the advent of the transistor. They fought to survive and got to an impressively small size and power consumption (such as the "6CW4 Nuvistor" shown HERE).
A RepRap only needs to follow a set of movement instructions with a few interupts. If the instructions were formatted so no real analysis of them was required (I'm not going to suggest punch-cards too, but..) it seems a relatively simple control circuit could interpret them.
A metal spike with a "halo" of metal on the top of a ceramic (or other non-conductive) wall around it, and a collector mesh suspended over it. It would seem within the current design geometry of the reprap, if it could print in the right materials.
And of course it would give the reprap an impressive resistance to EM interference and ionising radiation. Perfect for that orbital construction platform.
The design of a diffusion pump and rotary backing pump would also seem simple enough to be 3D printed with some ease (barring the oil required), so acquiring a working vacuum state is not the biggest stumbling block. If anything that would be the issue of cooling it all.
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Peter "Sci" Turpin
London, England
Provider of practical solutions.
(Sometimes stellifying Jupiter IS a practical solution)
But if you have a vacuum environment on hand already, it's also good for thermionic valves.
The idea of printing huge glass bulbs is right out of course, but valves didn't die off right away with the advent of the transistor. They fought to survive and got to an impressively small size and power consumption (such as the "6CW4 Nuvistor" shown HERE).
A RepRap only needs to follow a set of movement instructions with a few interupts. If the instructions were formatted so no real analysis of them was required (I'm not going to suggest punch-cards too, but..) it seems a relatively simple control circuit could interpret them.
A metal spike with a "halo" of metal on the top of a ceramic (or other non-conductive) wall around it, and a collector mesh suspended over it. It would seem within the current design geometry of the reprap, if it could print in the right materials.
And of course it would give the reprap an impressive resistance to EM interference and ionising radiation. Perfect for that orbital construction platform.
The design of a diffusion pump and rotary backing pump would also seem simple enough to be 3D printed with some ease (barring the oil required), so acquiring a working vacuum state is not the biggest stumbling block. If anything that would be the issue of cooling it all.
--
Peter "Sci" Turpin
London, England
Provider of practical solutions.
(Sometimes stellifying Jupiter IS a practical solution)
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Re: An old-school solution to printing reprap electronics? February 03, 2010 03:00AM |
... for sealing against vacuum you can search for ferrofluids optimized fo vacuum - it's only a bit pricey 
But then you can build slow rotatong vacuum-pumps too with ferrofluid as evacuating agent ...
Viktor
But then you can build slow rotatong vacuum-pumps too with ferrofluid as evacuating agent ...
Viktor
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Re: An old-school solution to printing reprap electronics? February 03, 2010 09:57AM |
Presuming that's dual-purposing it for vacuum seals for gaining access to the chamber too? I've not used oil seals before. Most of my experience has been in rubber (viton) or copper gaskets. Also RTV silicone for my home made degasser. Hatch-style, a knife-edge seal could work fairly well, though would need a good pumping speed to suck the surfaces together. I can see a viscous oil would certainly make it work a lot better! Good for sealing any smaller gaps in a mechanical seal.
Perhaps an airlock with gate-valves is a possibility? It wouldn't mean letting the whole production chamber up to air, and sliding access doors could be made with several layers of guide channels/runners would provide an appreciable baffle to air ingress.
As an alternative to ferrofluids, what about hot glue? It should seal acceptably when set, but when heated could allow it to be opened.
Of course, probably not as good as a pumping fluid too.
Also encouraging the issue is more with creating a vacuum than making a vacuum-tube controlled RepRap.
--
Peter "Sci" Turpin
London, England
Provider of practical solutions.
(Sometimes stellifying Jupiter IS a practical solution)
Perhaps an airlock with gate-valves is a possibility? It wouldn't mean letting the whole production chamber up to air, and sliding access doors could be made with several layers of guide channels/runners would provide an appreciable baffle to air ingress.
As an alternative to ferrofluids, what about hot glue? It should seal acceptably when set, but when heated could allow it to be opened.
Of course, probably not as good as a pumping fluid too.
Also encouraging the issue is more with creating a vacuum than making a vacuum-tube controlled RepRap.
--
Peter "Sci" Turpin
London, England
Provider of practical solutions.
(Sometimes stellifying Jupiter IS a practical solution)
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