Building a rocket engine from scratch
blog.ablspacesystems.com
Building a rocket engine from scratch
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Re: Building a rocket engine from scratch
#2"At one point, I received a well-deserved earful from our machinist about how tightly spaced the turbine blades were. The program was taking nearly a month to run and required tiny end mills that broke often. We performed a turbine blade count study to see if we could use fewer blades with more space between them. It turned out the performance impact of running fewer blades was minimal, so we cut the number down, allowing our machinist to use larger, less fragile tools. Machine time dropped to less than a day, which was a significant win for turbine cost and machine time. It was also a good lesson in thinking comprehensively about a design’s manufacturability (those passages between the blades looked so big on the computer screen!) in addition to its performance. "
Once again people learn the hard way that it's valuable to have tight feedback cycles and embedded knowledge on your team.
Re: Building a rocket engine from scratch
#3"At one point, I received a well-deserved earful from our machinist about how tightly spaced the turbine blades were. The program was taking nearly a month to run and required tiny end mills that broke often. We performed a turbine blade count study to see if we could use fewer blades with more space between them. It turned out the performance impact of running fewer blades was minimal, so we cut the number down, all…
And also the value of a completely obsessed engineer. If the mech eng designing the parts is also the type to build things in his spare time, this type of machining problem would stand out right away.
Of course, not everything can ever be anticipated, so tight feedback loops are fantastic when you can get them.
Re: Building a rocket engine from scratch
#4Nice read. The fact that it is possible to 3d print metal parts that withstand temperatures and pressures of a rocket engine is so exciting. How expensive is it?
Re: Building a rocket engine from scratch
#5Nice read. The fact that it is possible to 3d print metal parts that withstand temperatures and pressures of a rocket engine is so exciting. How expensive is it?
Stratasys? I’m not sure about pricing, and the website won’t say.
However, a bunch of places rent out time on those machines. Draw up your rocket, and get a quote. Price is generally cc^2 volume
Metal is not cheap. Make a few out of plastic to verify dimensions.
Re: Building a rocket engine from scratch
#6Nice read. The fact that it is possible to 3d print metal parts that withstand temperatures and pressures of a rocket engine is so exciting. How expensive is it?
Mostly depends on the volume of the part, or equivalently it's weight. Complexity you get mostly "for free" when it comes to 3d printing. What type of material you need to "withstand temperatures and pressures of a rocket engine" is entirely dependent on which part of the rocket engine we're talking about. A fuel injector has radically different requirements than a supporting strut for example.
3d printed titanium goes for 300-400 USD/kg, steel is a bit cheaper at ~150 USD/kg for most inconel grades.
Re: Building a rocket engine from scratch
#7now all that is required is a github for passive radar...for educational purposes
Re: Building a rocket engine from scratch
#8Nice read. The fact that it is possible to 3d print metal parts that withstand temperatures and pressures of a rocket engine is so exciting. How expensive is it?
side question to this: where can i design stuff involving metal parts (presumably in CAD tools) and have it printed en masse? With PCBs? ex) car components
Re: Building a rocket engine from scratch
#9Nice read. The fact that it is possible to 3d print metal parts that withstand temperatures and pressures of a rocket engine is so exciting. How expensive is it?
Very. Very. Expensive.
Inconel powder is also Not That Great for your health and at the particle-size the printers rocket companies use, you need full PPE to safely handle the loose powder floating about.
The machines themselves are also expensive. Think in the millions of USD. EOS, SLM, and Velo3D are key players in this market. They require a fair bit of space, and training to use correctly.
You probably need a mechanical engineer who is well-versed in materials science and has a tolerance for finicky machines that constantly breakdown.
Then you have the metal powders. Which, also potential million or two.
And then you have all the associated infrastructure needed. High voltage power. Gas (Nitrogen, Helium, Argon, etc etc) in the thousands of liters per month. Waste disposal. Safety (some alloys are flammable in their powder form). Climate control (the powders are sensitive to the environment. Humidity will quickly destroy your powder supply). Tooling (the base-plates metal printers used are machined from solid blocks of steel).
And last but not least, any of the post-printing work. Heat treat. Coatings. Analysis. CNC Machining.
3D Printing metal on industrial scales is a CAPEX intensive endeavor, and not for the faint of heart.
Re: Building a rocket engine from scratch
#10Nice read. The fact that it is possible to 3d print metal parts that withstand temperatures and pressures of a rocket engine is so exciting. How expensive is it?
Stratasys? I’m not sure about pricing, and the website won’t say. However, a bunch of places rent out time on those machines. Draw up your rocket, and get a quote. Price is generally cc^2 volume Metal is not cheap. Make a few out of plastic to verify dimensions.
Plastic to verify dimensions is a great approach.
But don't forget that the laser sintering of metal powders might result in design constraints not present in plastic printing!