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OT--3-D Printed Jet Engine???


Yes, but they're not telling us what "post printing" work was done, such as turning bearing journals, inserting traditionally manufactured ball bearings, precision balancing (you're not spinning a printed rotor to 33K without balancing it), prepping the injectors by accurately drilling their orifices to size, etc. Not to mention screws and tapping and...

Not that I know they did all these things, but it's damn likely. 3D printing is amazing, but nobody is going to be using anything commercially available to make a working (rotating element) jet engine right out of the box. A pulse-jet, maybe.
 
No doubt, but if you view it as making castings that still need to be finished without having to make patterns or molds, it still is awesome.

Bill

That's essentially the point.

SpaceX uses a comparable DMLS process for the manufacture of their Super Draco thrusters out of inconel powder.

I'm sure someone still has to bore critical diameters to press in components, or drill-and-tap mounting bolt patterns. It's a giant leap forward in speed and cost compared to low-quantity castings. It also eliminates some of the design compromises of geometry in using castings.
 
I noticed that they said that they spun it up to that speed. There was no mention of any thrust being generated or of any fuel being burned.
 
It appears to be running on it's own power, and they did specifically show it (in a Haas of all things) getting finish machining. I can't imagine it being terribly efficient without significant finish work, and there are obviously parts that could not be grown (bearings, for one). But it is a good next step, and shows a lot of promise. It must be nice to have unlimited money from the government to play with.
 
I don't think I've seen anyone even surmise that we're close to being able to print critical flight parts directly from the SLS/FDM/DMLS/DMLM machine and put it directly into flight.
 
I don't think I've seen anyone even surmise that we're close to being able to print critical flight parts directly from the SLS/FDM/DMLS/DMLM machine and put it directly into flight.

All of the parts in those applications produced by other processes have some sort of post processing. Using more printed parts is closer than some here are comfortable with. GE and Boeing have several coming online in the not too distant future.

The FAA Cleared the First 3D Printed Part to Fly... - GE Reports
 
All of the parts in those applications produced by other processes have some sort of post processing. Using more printed parts is closer than some here are comfortable with. GE and Boeing have several coming online in the not too distant future.

The FAA Cleared the First 3D Printed Part to Fly... - GE Reports

That's a good example right there. That housing is obviously more in-line with the "think of it as a casting" idea. Most of it is "as-cast" (sintered) but get obvious machining done to critical features. Holes are still drilled out, the connectors fully machined, etc.
 
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Also don't forget about these:

The whole engine isn't direct-metal, but they do one-piece spark-eroded turbine disks.

 

DMLM, ie laser melting, that's good stuff. Non-porous.

Gas microturbine isn't a bad idea for stress-testing those sorts of processes. They will wear differently to conventionally formed versions of the parts.
 
I noticed that they said that they spun it up to that speed. There was no mention of any thrust being generated or of any fuel being burned.

Dude, you don't get flames out of the back of something with compressed air, that's clearly running as a jet engine with a combustor.

Think a whole row of blowlamps driving a fan ya. Hot in there. Very hot in there.

33,000 rpm on a 6 inch diameter turbine rotor is doing 99,000ips on the outer edge of the blade, around 5625mph, and pulling a loop-the-loop 550x per second. That's quite a lot of stress, parts when heated up to X,000ºC in the hot end of the turbine, that's pretty violent treatment, equivalent to being stretched, bent and abrasive blasted while heated with a blowlamp.
 








 
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