/sci/ - Science & Math

>>15748396
it's hard to get the cooling channels needed for raptor 3's heat flux performance by forging or traditional milling, and I'm pretty sure spacex has stated they print the MCC for raptor.

also, Merlin 1D was explosive formed for the outer stainless jacket, not forged. The inner copper jacket is conventionally milled and brazed, picrel is a merlin 1D inner copper jacket with the cooling lines already milled. Elon Musk, 2011:
>The hardest part of the engine to mass produce is the electro-plating of nickel cobalt on the chamber. (editing for clarity: SpaceX does NOT use that process) We create this thick metal jacket that takes the primary stress of the pressure vessel and it’s plated one molecule at a time. Plating is about the slowest way you can make a metal thing (so, they don't do it). With the Merlin-1D we take a metal jacket that is explosively formed. We take a metal sheet that’s in a cylindrical form and put it in a bucket of water, effectively. Sort of a concrete pool. And you set off an explosive and the jacket just goes “boohmp” and forms to the outer side walls into a jacket shape, so you have a mold, effectively. And then you just put the jacket on the chamber and braise it on. You can do several a day. We have a fully integrated engine and it’s being test-fired right now. There’s really not a lot of question marks remaining about the Merlin-1D.
https://spacenews.com/elon-musk-chief-executive-and-chief-technology-officer-space-exploration-technologies/

This is an excellent video that goes over the electroplating process Musk was talking about (that spacex avoids because it's too slow)
https://www.youtube.com/watch?v=H4YZxb2E5PA
he's also just started a series on making a monoprop rocket engine from scratch, breaking taps is a great channel

explosive hydroforming, like they do for Merlin's outer stiffening jacket
https://www.youtube.com/watch?v=CbS6rS0seuk