Do astronauts print 3D in space with supports? They are needed only because of gravity, which - on a space station - obviously is not a problem.
$\begingroup$
$\endgroup$
2
-
2$\begingroup$ People use "in space" to mean several different things. In this case, by "in space", I assume you mean "in free-fall", as opposed to "in a vacuum", or "unshielded from solar radiation", or "not on Earth", or ... . $\endgroup$– Ray ButterworthApr 9, 2019 at 13:21
-
$\begingroup$ One of the more interesting aspects to consider would be the cooling of thermally deposited prints (FDM, etc). The general lack of convection may actually make things better, but will probably require some changes in strategy particularly fan algorithms. $\endgroup$– Chris StrattonApr 9, 2019 at 16:48
Add a comment
|
2 Answers
$\begingroup$
$\endgroup$
5
Supports are not needed "just" because of gravity. They hold pieces in exact position relative to the "bed" (and so relative to the coordinate system).
With most printers the model moves during print in at least one position, whether Y or Z, and if you just suspended some pieces in midair when they are not connected to the main body during print, they would just stay in space relative to the printer main body/station, so they would effectively move against the rest of the print and ruin your day.
On the other hand "suspending" layers without any support would probably not be possible anyway, because they would stick to your nozzle (for FDM, but imho most other technologies have some similar problem).
-
$\begingroup$ I think this is true for supports generated for supporting elements because the connection to the main body is above the lowest point of the element, meaning that it would be floating in mid air as you say, but it probably would eliminate the need to support large overhangs. $\endgroup$– James TApr 9, 2019 at 13:39
-
$\begingroup$ "if you just suspended some pieces in midair when they are not connected to the main body during print, they would just stay in space relative to the printer main body/station" I suspect you'd find the extruded material would be pulled along after the nozzle. Viscosity effects overcome gravity here on Earth; material extruded in mid-air sometimes falls to the bed, but often just bundles up on the nozzle. In space I'd expect it to do so even more readily. Supports are there to give something other than the nozzle for the material to stick to as much as they are to actually hold it up. $\endgroup$ Apr 9, 2019 at 16:29
-
$\begingroup$ @anaximander I hoped I covered that with the last sentence but maybe it is not understandable? $\endgroup$– jkavalikApr 9, 2019 at 17:12
-
$\begingroup$ @JamesTrotter yes, the support requirements will be different, but imho not that much. Bridges do not need supporting even now, with zero-g they would just not sag at all. Overhangs can even on Earth actually curl up and supports are sometimes needed to keep them down in my experience. $\endgroup$– jkavalikApr 9, 2019 at 17:15
-
$\begingroup$ I feel like if you went slow enough with sufficient cooling, you could do a 90 degree bend on an overhang in space which would have a significantly higher change of failure under earths gravity... but thats a very specific problem. $\endgroup$– James TApr 10, 2019 at 8:01
$\begingroup$
$\endgroup$
3
I have no links to validate this answer, but with a few years of 3D printing behind me, I can attest to the effect of gravity on 3D printing.
Micro-gravity would be a boon for earth-bound 3D printing enthusiasts. There would be no droop to the filament when bridging (spanning open areas) and no fallen models without support. The construction of each layer would be dependent on the bond to the previous layer which is how it's done on the planet, but there would be no outside force (is gravity an outside force?) causing the new layer to fall. There would be no fall, so to speak, because the entire model being printed is falling around the earth at the same rate.
There are 3D printers described as five-axis printers which rotate the model in three-space to direct the filament "downward" respective to the desired placement, but it's not really artificial gravity.
Zero-G would enable some creativity that is unavailable to mere mortals. Loops of filament could be extruded without sag, allowing for intricate latticework and rather stunning artistic creation.
-
2
-
$\begingroup$ I can't help but wonder though, in the case of FDM printing, would it actually work as well as you're suggesting, or would the adherence of the filament to the nozzle cause the moving nozzle to impart momentum to the filament, making it move in other (unwanted) directions? $\endgroup$– Doktor JApr 9, 2019 at 16:16
-
2$\begingroup$ Upvoted for the bridging realization - performance there would indeed drastically improve. However, curves and verticies in free space will not work any more than they would in a terrestrial case where bed adhesion is lacking. $\endgroup$ Apr 9, 2019 at 16:47