|
|
Post by doctorsquared on Jun 24, 2019 0:15:55 GMT
How can additive manufacturing work for metals in orbit? The only way that I know of to "3D print" metals is with a power bed, but this requires gravity to keep the power flat on the base plate. I don't think that liquefying metal and printing it the same way as melted plastic filament is viable but I might be wrong. I found some mentions of it on Google but no explicit explanation of how it works. There are a few other options: Desktop Metal uses a FDM (Fused Deposition Manufacturing) process using plastic rods infused with the metal powder being used. Parts are printed on an FDM printer, the polymer is evaporated in a solvent bath (which could work in zero-g if kept under pressure or in a centrifuge), and then the remaining metal part is sintered in a furnace. Admatec and Tethon3D have developed a DLP (Digital Light Processing) process that suspends the metal powder in a UV-curable polymer resin. A build plate is submerged in the resin tank and an LCD display covering a UV light source turns its pixels on and off the selectively cure the resin, layer by layer into the final part. It is then sintered in a sintering furnace to densify the part. This could work in zero-g since the printer could be rotated in a centrifuge or an inert atmosphere within the printer could be pressurized to help hold the resin bath in place. Arcam AB (now owned by GE) and Chervona Hvilya melt a metal wire (fed similar to an FDM plastic filament) with an electron beam source to form metal parts that don't require sintering. This method is currently used by General Electric's aviation division to build turbine blades for jet engines and is better suited to building larger-scale components. Other processes like metal injection molding or extrusion would also probably work in zero-g since those processes rely on pressure and fluid flow, rather than gravity to make it work. |
|
feld
New Member
Posts: 45 
|
Post by feld on Sept 18, 2019 14:43:08 GMT
I HAVEN'T had time to read the thread in detail. I hope I do not offend by just air dropping in a (perhaps obvious) place to look for an answer. But look at everything this company does. It might contain the answer: madeinspace.us/They are trying to make themselves leaders in the field and are the people who put the first 3D printer on orbit. Please be advised that that printer is NOT metallic. But they definitely are working in metals. v/r feld |
|
|
|
Post by luxardens on Nov 23, 2019 16:04:57 GMT
Bit late to the discussion but my university has a fully 3D (robotic) welding arm that does additive manufacturing with normal steels and it can add to the side and underneath a surface. So seeing how it can act against gravity, I suppose the concept would do just fine in zero-G. I've seen videos online of similar setups for titanium, not sure what those use but the ones tor welding steel simply melt a wire under a protected atmosphere. Wire gives pretty coarse results though, several mm definution sizes, rather than the molecular precision required in CDE.
|
|
|
|
Post by Pttg on Nov 23, 2019 19:54:56 GMT
Bonus: Suppose you want to make a very, very low-density structure. If you use very limited centripetal force, or heck, just use a minor asteroid, you get the lightest dust snowfall, perhaps leading to different behaviors once it's sintered. If you want high density, spin it like an unbalanced clothes dryer and get 2+ Gs of compression in the powder.
|
|
|
|
Post by linkxsc on Aug 4, 2020 18:49:45 GMT
Bit late to the discussion but my university has a fully 3D (robotic) welding arm that does additive manufacturing with normal steels and it can add to the side and underneath a surface. So seeing how it can act against gravity, I suppose the concept would do just fine in zero-G. I've seen videos online of similar setups for titanium, not sure what those use but the ones tor welding steel simply melt a wire under a protected atmosphere. Wire gives pretty coarse results though, several mm definution sizes, rather than the molecular precision required in CDE. Sudden thought that hits me. I own a few plastic FDM printers (a couple ender 3s, cr10 and a couple others). A can they work when placed on their side or upside down (mechanically I can't see a problem. but layer adhesion and etc might be an issue). And could this help when printing specific overhangs that can't be produced normally? Could one, say mount the whole printer in a jig that rotates, and when doing certain features, will rotate the whole unit to a proper angle such that gravity will help out. |
|
|
|
Post by luxardens on Oct 8, 2020 11:01:01 GMT
Bit late to the discussion but my university has a fully 3D (robotic) welding arm that does additive manufacturing with normal steels and it can add to the side and underneath a surface. So seeing how it can act against gravity, I suppose the concept would do just fine in zero-G. I've seen videos online of similar setups for titanium, not sure what those use but the ones tor welding steel simply melt a wire under a protected atmosphere. Wire gives pretty coarse results though, several mm definution sizes, rather than the molecular precision required in CDE. Sudden thought that hits me. I own a few plastic FDM printers (a couple ender 3s, cr10 and a couple others). A can they work when placed on their side or upside down (mechanically I can't see a problem. but layer adhesion and etc might be an issue). And could this help when printing specific overhangs that can't be produced normally? Could one, say mount the whole printer in a jig that rotates, and when doing certain features, will rotate the whole unit to a proper angle such that gravity will help out. That's a cool idea. I wouldn't assume FDM to work upside down out of the box, but then again I can't see any reason either why it wouldn't at least feed correctly because the rollers can easily overcome gravity and the extrusion is because of the pressure pushing the liquid, not the liquid "falling out". I say build one! All it takes is two actuators to rotate it across any angle, though it might be a bulky setup (and writing a program to rotate it automatically would be absolute hell). |
|
