China is an interesting country to report on when it comes to 3D printing because the innovations seem to come fast and furious. WinSun is 3D printing houses in 24 hours, but are they 3D printing them on site? Are they printing walls, adding other components, and using a combination of traditional manufacturing? They are.
I think one of the more deceptive practices in 3D printing journalism is the practice of taking claims like “the world’s first 3D printed x” and not really even mentioning or investigating that numerous other processes were used to create the finished product. It gives people and unrealistic view of what 3D printing is capable of. That’s not to say that, every once in a while, somebody pushes the bar a little higher.
At first glance, the first ever Chinese National Defense Science and Technology Industry Exhibition seems like a typical calling card for a nation’s military agenda. This is the first time that all branches of the Chinese military have presented a unified front, and it’s within the Chinese sector of the military-industrial complex. These types of events are supposed to show off a rapid pace of innovation that will amaze, astound and fascinate other nations and people around the world.
As is typical of many press releases, there is a claim and display: Here is the world’s largest 3D printed titanium alloy load bearing frame for an aircraft ever printed. Yet, it kind of looks like it has had a bath in a CNC machine or other traditional manufacturing process. There is no footage of it being printed or finished, it just comes out perfect, huge, and impossibly fast.
Here’s the official story:
Scientists from Beijing University of Aeronautics and Astronautics have printed over 50 large components for aircraft and aircraft carriers used laser powered 3D printing technology. At the exhibition, staff said that the production cycle was reduced by 80% by 3D printing these components. They also showed exhibition goers a laser sintered C919 aircraft cockpit window frame that they claim can was 3D printed in just 55 days. No word on the cost, but this type of product would supposedly take 2 years and $2 million to make using traditional manufacturing methods.
What I want to know how much this actually cost to build? I think we can be optimistic about the possibilities of 3D printing as it applies to the aerospace industry. GE’s additive manufacturing team printed out a functioning mini-engine, and I see nowhere near that level of innovation coming out of China. Sorry, but I’m a little skeptical of this story.
Look closely and let me know what you think. Am I way off here? Dear Chinese media (which is where everyone broke this story from), tell me how much it cost to 3D print, what other processes were used to manufacture it, and I’ll make a decision on whether or not to be impressed. Boom. Shots fired.
Thanks for this true story!
That last picture shows very clear milling machine marks.
maybe milling machine was used for surface finish
If you were going to go to the trouble of setting up a milling machine for finishing, you may as well have used it to produce it in the first place.
Sorry, this just doesn’t ring true.
Looks very similar to what Lockheed is doing (with titanium) on the F-22 with
Sciaky, Inc. using Electron Beam Additive Manufacturing Welding. This
produces a near net shape that is final machined.
Thank you for trying to put some light about all these declarations. Using SLM and EBM, I can assure you that such a piece has been undergoing heavy post machining. And by the quick look of it, I’d even guess that little to nothing has been made via AM.
Agreed. Looks milled. True that it may have been done for surface finish, but I also question that part. Why 3D print that? It’s not a difficult part to mill. It just doesn’t make sense to me. It’s also an easy part to print structurally, and perhaps that’s one reason to print, but there’s no way you wouldn’t opt for milling there. Also, why the forced perspective shot to show the part larger than it is (factory vs. against the table). You can also spot the mill lines on the left side of the Factory shot… oddly, they seem to be the same size as those in the table shot and clsoe up… Yup, something just doesn’t sit right here.
Yes it has. Optomec and Sciaky as well as other major US defense contractors such as Boeing & Lockheed have been printing similarly sized parts for years using LENS (also called Direct Metal Deposition, EBAM and a host of other things), the parts are printed and then usually post processed with CNC. This step would account for the smoothness.You could make this part with a Sciaky 300 system which can build parts up to 5.7m long. There are several US fighter and other military aircraft that use DMD parts on them. There has been a lot of research done in China on LENS and they’ve been steadily increasing their capability. Even though it does not have the fine detail you can produce with DMLS, LENS lets you make large structural aerospace parts. Here is a video of Sciaky EBAM: https://www.youtube.com/watch?v=A10XEZvkgbY Usually LENS is used to repair high end aerospace and defense systems as well as turbines in general: http://www.optomec.com/wp-content/uploads/2014/04/LENS_850-R_datasheet.pdf This is an example of a hybrid machine whereby a LENS system is on a CNC system: https://youtu.be/Ttt3nMKr9Oo
My concerns are:
1) If it is 3d printed, why was EVERY surface post machined? They shouldnt need smooth machined surfaces inside those weight saving pockets… the pockets should have been left “as-printed” to show off the technology and reduce cost.
2) How are they dealing with residual stress? I know titanium is notorious for internal stresses building up during the printing process… this big piece would have wanted to warp like crazy… In an EOS machine (i know i know, different technology, but the same basic principals apply), I have personally warped a 1″ titanium base plate over 1/8″ just by building a few horizontal tensile bars.
It’s not unreasonable to say these components were 3D printed. They were almost certainly printed on various directed energy deposition systems, for which there are at least historical asian providers for these types of systems (also could have been on more well known DED systems from Optomec, etc). This type of metal AM is well known for near net-shape capabilities. The minimum feature size of these systems is orders of magnitude larger than a laser powder bed fusion system, but still capable of layer by layer production at a small enough level to achieve good characteristics once machined. Even though its universally (well, apparently not) understood that any part printed from these types of systems HAS to undergo significant machining to achieve what you see in the pictures, the benefit is still there. The systems can deposit metal insanely fast compared to powder bed systems, and the part size is theoretically unlimited although typically just really really large.
Believe it or not, these types of DED systems have been sold for well over a decade.
-Scott @ SmarTech
This is nothing special and nothing new – we can do much larger and more intricate fully finished parts in one hit (Wind Turbine and Submarine parts) however great to know that the technology is now readily available in more parts of the World.