The International Cessna^® 170 Association

Interesting question regarding owner produced part. I'm sure the FAA will address it as the 3D printer becomes obsolete in favor of the replicator from Star Trek.

The other month EAA Chapter video had about the 3D printing and how it will change the home building process.

John

flyboy122 wrote:One of the young engineers at work said that back in school they used one 3d printer to print the parts for a second 3d printer! The only thing missing is Skynet and we'll all be redundant...

I would classify a part downloaded from the internet, in which the owner arranged the have it printed, picked colors/materials/etc..., to be "owner produced". I don't see the modeling as much different than having someone do a machining or welding operation for you. That being said, this is one of those things the FAA is notoriously vague on, so I wouldn't fault someone else for holding a different opinion.

DEM

Seems legit to me. SO long as the owner is involved in the process.

For structural parts, you'd need accepted data showing the printing technique used will generate an equivalent part.
Printing a sump is completely possible as an owner made part but you'd need documentation showing that the printing process was as good as the casting process. Also, I don't think they can print in magnesium so you'd need acceptable data showing equivalent material as well.

For non structural parts like buttons and plastic dressing I think you'd need burn tests for the material.

And how many scribes were there before the printing press???

You do realize that computers and 3d printers are as revolutionary as the printing press. right?

Sounds like a good time to plug my cousin's book:

"Gutenberg's Apprentice" by Alix Christie

It is a novel about the great disruptive technology of movable type. A well researched volume published last year about the technical aspects of making the type work, as well as power, suspicious governments both church and state, venture capital, startup companies, inventors. A good read. (Alix and I both grew up setting type and printing in our grandfather's print shop)

Falco, a man who understands my point through my same experiences, that of an apprentice printer who learned the old ways yet was the new generation who ushered in the computer age to printing and helped destroy what it was. Folks, printing is not what it use to be. There are no rules any more, anything goes.

A quick story. We printed other newspapers than what our family owned. In many cases we set the type for those papers. One Editor/Publisher/Owner would right his headlines for us to set and they needed to be set in a set size and of course fit the column. If they did not fit the column he would rewrite them. When I pointed out I could simply set the type in 17.9 rather than 18 point, he was appalled that I would do such a thing. He said he would cheat no human of their rightfully earned 18 point obituary head.

The point was there had to be standards. In many cases standards where set because of limitations of technology or the small group of skilled artisans who maintained a standard. With the new technology there was no limitations and no controllable group to keep a standard. With no standards chaos is not far behind. Think of this, 20 years from now you want to buy a 170, but you don't really know what a 170 is suppose to be because for the last 15 years all sorts of parts have been printed by who knows and to what standard.

I see the same thing happening in many of the skilled arts and professions. There will be fewer and fewer humans who understand the basics of how and why because they don't have to know. Fewer people with real knowledge and skill and more chaos.

Sorry for getting back up on my soap box. On one hand I think the knobs are cool, the big picture just scares the heck out of me.

One man's advancement in technology is another man's poo poo.

Bruce Fenstermacher wrote:Think of this, 20 years from now you want to buy a 170, but you don't really know what a 170 is suppose to be because for the last 15 years all sorts of parts have been printed by who knows and to what standard.

It's my understanding this has been happening to 170's for the past 70 years. Who hasn't found a questionable repair or undocumented part on their aircraft? How is 3D printing any different than me drawing a knob on a napkin and taking it to my local machine shop? A napkin sketch requires less effort and knowledge than modeling up a 3D print job in CAD. How many machine shops will question the appropriateness of the designs their customers bring them? I don't see how the manufacturing method chosen will result in enforcing a "standard".

I understand the fear of new tools that seem to make it easier for someone to make their own parts, but I don't see 3D printing as the path to chaos. I'm an engineer and I custom design surgical instruments for neurosurgeons. It is a heavily regulated environment much like the FAA. You would be shocked and appalled (as I am) to see how many surgeons modify surgical instruments in their garages, before bringing them back to the hospital and using them on YOU in the operating room. From my observations, 3D printing has not resulted in an increase in surgeon modified instruments. If anything, 3D printing has made it so I can produce parts faster and cheaper, so that more surgeons are willing to use the "correct" channels to modify their instruments. In my industry, 3D printing is increasing speed, safety, and standardization of the product. And that has major benefits for my patients.

rusbac wrote:

Bruce Fenstermacher wrote:Think of this, 20 years from now you want to buy a 170, but you don't really know what a 170 is suppose to be because for the last 15 years all sorts of parts have been printed by who knows and to what standard.

It's my understanding this has been happening to 170's for the past 70 years. Who hasn't found a questionable repair or undocumented part on their aircraft? How is 3D printing any different than me drawing a knob on a napkin and taking it to my local machine shop? A napkin sketch requires less effort and knowledge than modeling up a 3D print job in CAD. How many machine shops will question the appropriateness of the designs their customers bring them? I don't see how the manufacturing method chosen will result in enforcing a "standard".

I understand the fear of new tools that seem to make it easier for someone to make their own parts, but I don't see 3D printing as the path to chaos. I'm an engineer and I custom design surgical instruments for neurosurgeons. It is a heavily regulated environment much like the FAA. You would be shocked and appalled (as I am) to see how many surgeons modify surgical instruments in their garages, before bringing them back to the hospital and using them on YOU in the operating room. From my observations, 3D printing has not resulted in an increase in surgeon modified instruments. If anything, 3D printing has made it so I can produce parts faster and cheaper, so that more surgeons are willing to use the "correct" channels to modify their instruments. In my industry, 3D printing is increasing speed, safety, and standardization of the product. And that has major benefits for my patients.

Exactly, Christine. YOU are an engineer. YOU have the knowledge, education, experience, and judgement to create parts that are as good or better than the originals. YOU are the type that would take careful measurements and create a part that is indistinguishable from a factory part to even the most discerning critics.

Historically, aviation has had some cheap asses. The FAA wouldn't have grown to be so nebulous with regard to ICA standards if some people weren't so cheap and lazy. I'm not saying that the average owner can't do these things well, but there are some people that scare me as pilots and some airplanes that are maintained by mechanics that I wouldn't even sit in on the ground. Someone that has no barometer for quality will have his grandson peck something out on the computer that looks "about right" and will put that on his airplane. I've seen some abominations to 170s over the years. The difference between doing something and doing something well is monumental. You didn't go to engineering school for no reason...you had to learn the methods to measure and design philosophy...and math...and all sorts of technical nuances that the layman doesn't understand or care about. Rednecks can "fix" anything, but they didn't design the space shuttle, nor did they the Cessna 170.

So I agree with you, but I am also very hesitant to blindly accept a digital copy of something for an airplane if I don't know its fidelity or if its fidelity has remained intact. I wish we had something on here like "Restoration Resources" that members could use for making parts or sources for high-quality restoration of instruments, or even a very complete library of original finish schedules that could be taken to a paint shop (I realize we have a few Cessna shop drawings) or interior stitching patterns. If you could model the ends of a cabin assist strap such that it could be 3D metal printed and subsequently chromed for a flawless external appearance, I'd donate a handle to the cause. I can measure and draw in 2D, but 3D stuff I have not yet learned.

Are 3D printed parts somehow exempt from FAA regulations as such that some kid can start making pistons with his makerbot?

Who's talking about blindly accepting anything and why is it that a new technology will mean the downfall of standards and quality to the point that the world will fall into chaos?

Did the world really turn into a worse place because we can choose our own font?

If this was the 1930s you'd be complaining how ailerons are distorting aviation and we should all stick with the original wing warping.

Oh my gawd these new fabrics people are using! We're going to loose the skilled craft of cotton wings and people will use any old plastic fabric they can find! The sky is falling.

Are you people serious???

I guess I've been spending too much time around old people.

I've historically connoted 3D printed parts with rapid prototyping, and therefore, inferior quality. At Horizon, all of the foam airplanes you see that are fully tooled started off life as EPS beer cooler foam blocks CNC milled down to the CAD drawing, and SLA plastic parts were printed for the reinforced areas. These airplanes were substantially heavier and substantially weaker than a tooled, injection molded EPO foam airplane with tooled, injection molded plastic parts. Christine's 3D printed knob was the first 3D printed part that I've seen that has any sort of decent resolution.

I realize the technology is comparatively in its infancy, but my impression of it thus far has been that it's great for mockups, but not final parts.

Back in my hole, where it's safe and the practices of the old world remain intact, I go...

Ryan Smith wrote:I guess I've been spending too much time around old people.
...
I realize the technology is comparatively in its infancy, but my impression of it thus far has been that it's great for mockups, but not final parts.

Tell that to GE

http://qz.com/667477/ge-fires-up-worlds ... tal-parts/

I'm an idiot. Got it.

Christine, if I had the ability to get a 3d printed knob or some other part such as panel bezels, I'd go for it. I'm not criticizing you for doing it. I built a CNC router with the intent to use it to make some airplane parts.

My example of parts for a 170 was an example. Could be applied to anything that is manufactured. Bogus parts for your car for example. It seems to me 3D printing will turn our manufacturing upside down, what manufacturing we still have.