Ryan - I felt like I was teleported right back into the AMC and your office on Lab! Great video. Very glad to see post processed lattice structures getting some serious MSR attention. Keep up the super work and continued best wishes on success in flight qualification.
Thanks for teaching me about crushable metal lattices. Using the chemical etching after printing is a super smart way to reduce the mass & thickness. Great episode!
I wonder if they’re slowly dipping the lattice into the etching solution to vary the final thickness from one end of the part to the other. The initial lattice layers that absorb impact are more “cushy” and get stiffer as the impact shock travel through the part and closer to the protected payload.
If etched with the wrong solution or for too long, it can. However, with the right chemical etching process, it does not introduce surface defector or degrade the performance; rather, you improve surface finish and surface quality, improving the overall performance. For standard parts, this generally helps improve fatigue performance. In the case of crushable lattices, it helps prevent premature failure and sustain a relatively flat crushing plateau.
The only way that I can think of would be through investment casting (essentially a single use mold) but I'm not sure you gain much from this. Also, it would be really hard to control solidification in these ultra fine ligament parts. Not saying it isn't possible, but strikes me as non trivial to do.
I do not have a good idea on how small you can make casted geometry, or if you can get the metal to flow through such small spaces, but was curious as to whether you had researched it.@@ryantwatkins
In an ideal world, we would directly print down to the final lattice thickness that we desire. However, many of our lattices require strut thicknesses on the order of 100-200 μm, which really push the limits of currently available Laser Powder Bed Fusion machines (at least ones that can print structures on the order of hundreds of millimeters). In some materials, you can print actually print down to a few hundred microns without the build crashing; however, the print quality is very poor (you get a lot of subsurface defects like voids and very bad surface finish) which significantly degrades the performance of your crushable lattice. So, the best way we've found to get around this is to print down to a lattice thicknesses that we can confidently get good quality, and then use etching to get us the rest of the way there.
@@ryantwatkins From brief images of nTops workflow used and the actual part seen in the video, it seems that design is uniform in the thickness and size of lattices. Was this chosen because varying thickness and size doesn't give value in able to protect the cargo, or because of the issues like in manufacturing (ability to control etching, printing), simulation (anisotropic property) ect.? Great video by AM Media and awesome project.Having samples from another planet deliberately taken and transported back is truly special. Best of luck. :)
@@JakovRudi This is still somewhat of an open question. In a pure quasi-static sense, I don't think you get much by grading strut thicknesses. In the case of dynamic crushing (which is what we care about here), the story is less clear because of inertial effects and wave propagation. So, for now, the easiest thing (and least complex) is to just maintain a uniform strut thickness. One clear place where it is beneficial is at lattices/solid interfaces(such as bosses) where it is beneficial to gradually thickness the ligaments as they get closer to the feature so as to improve strength locally.
I just wondered if you could sieve the powder to get a more uniform cross section in the parts and not have to use the chemical processing.@@ryantwatkins
@@3-der251 the powder is already sieved to control size. You might be able to use a smaller powder size but you can start running into clumping and other spreadability issues. Overall, printing finer features would require quite a few modifications to stock printers and the prints would be very slow.
Just keep in mind when this guy starts talking about aluminum and manufacturing of crucible mediums then you think how the hell did Tesla launch a Tesla Roadster into the thermosphere and have that survive😂😂😂😂😂 These people are not gonna do any of this they're just gonna tell you they did.. And then you'll say nah and then you'll show me a cartoon of the reactment of the Supposed launch and landing and crashing ha ha ha
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Ryan - I felt like I was teleported right back into the AMC and your office on Lab! Great video. Very glad to see post processed lattice structures getting some serious MSR attention. Keep up the super work and continued best wishes on success in flight qualification.
Great job fellow Ryan!! Exciting application.
Thanks for teaching me about crushable metal lattices. Using the chemical etching after printing is a super smart way to reduce the mass & thickness. Great episode!
this channel is gr8
This is peak content.
Big credit to nTopology that could make this design printable 🙌
I wonder if they’re slowly dipping the lattice into the etching solution to vary the final thickness from one end of the part to the other. The initial lattice layers that absorb impact are more “cushy” and get stiffer as the impact shock travel through the part and closer to the protected payload.
Are they pre - heating the lattice before dropping through this tower?
Awesome.
That sampel return mission is crazy fantastic. Love your channel, love 3d printing. Regards from Poland.
Dziękuję bardzo! (We hope that says "Thank you very much!")
@@AdditiveManufacturing Exactly. Thanks .
Does chemical etching not introduce surface defects or degrades the overall performance of the crushable lattice?
If etched with the wrong solution or for too long, it can. However, with the right chemical etching process, it does not introduce surface defector or degrade the performance; rather, you improve surface finish and surface quality, improving the overall performance. For standard parts, this generally helps improve fatigue performance. In the case of crushable lattices, it helps prevent premature failure and sustain a relatively flat crushing plateau.
Thanks Ryan, fascinating info. @@ryantwatkins
Are casting techniques anywhere close to being able to do this lattice?
The only way that I can think of would be through investment casting (essentially a single use mold) but I'm not sure you gain much from this. Also, it would be really hard to control solidification in these ultra fine ligament parts. Not saying it isn't possible, but strikes me as non trivial to do.
I do not have a good idea on how small you can make casted geometry, or if you can get the metal to flow through such small spaces, but was curious as to whether you had researched it.@@ryantwatkins
So first they add material just to remove it in next step. SLS alone can't handle small features?
In an ideal world, we would directly print down to the final lattice thickness that we desire. However, many of our lattices require strut thicknesses on the order of 100-200 μm, which really push the limits of currently available Laser Powder Bed Fusion machines (at least ones that can print structures on the order of hundreds of millimeters). In some materials, you can print actually print down to a few hundred microns without the build crashing; however, the print quality is very poor (you get a lot of subsurface defects like voids and very bad surface finish) which significantly degrades the performance of your crushable lattice. So, the best way we've found to get around this is to print down to a lattice thicknesses that we can confidently get good quality, and then use etching to get us the rest of the way there.
@@ryantwatkins From brief images of nTops workflow used and the actual part seen in the video, it seems that design is uniform in the thickness and size of lattices. Was this chosen because varying thickness and size doesn't give value in able to protect the cargo, or because of the issues like in manufacturing (ability to control etching, printing), simulation (anisotropic property) ect.?
Great video by AM Media and awesome project.Having samples from another planet deliberately taken and transported back is truly special. Best of luck. :)
@@JakovRudi This is still somewhat of an open question. In a pure quasi-static sense, I don't think you get much by grading strut thicknesses. In the case of dynamic crushing (which is what we care about here), the story is less clear because of inertial effects and wave propagation. So, for now, the easiest thing (and least complex) is to just maintain a uniform strut thickness. One clear place where it is beneficial is at lattices/solid interfaces(such as bosses) where it is beneficial to gradually thickness the ligaments as they get closer to the feature so as to improve strength locally.
Did you have to use an unusual powder granule size?
Not in particular. We use the standard powder that is used for Laser Powder Bed Fusion printers.
I just wondered if you could sieve the powder to get a more uniform cross section in the parts and not have to use the chemical processing.@@ryantwatkins
@@3-der251 the powder is already sieved to control size. You might be able to use a smaller powder size but you can start running into clumping and other spreadability issues. Overall, printing finer features would require quite a few modifications to stock printers and the prints would be very slow.
Just keep in mind when this guy starts talking about aluminum and manufacturing of crucible mediums then you think how the hell did Tesla launch a Tesla Roadster into the thermosphere and have that survive😂😂😂😂😂 These people are not gonna do any of this they're just gonna tell you they did.. And then you'll say nah and then you'll show me a cartoon of the reactment of the Supposed launch and landing and crashing ha ha ha