PLASTIC!

[the_imperfectionest]

Hello all!

I'm a bit new to the LE bunch!

Anyways, I have mostly restored a Maxair Hummer and now took on a Mitchell wing.

But I dunno, the whole energy of 'You ain't gunna tell me no!' of the LE is important to me.


To the business:

Has anyone tried to 3d print wing ribs?
If so what material?
If not, why?

As I ponder this, I also have to ask if anyone has measured the temps inside the wing cavities on extremely warm days. (PETg Plastic is moody(soft) up above about 190f)

And then I ponder if anyone has done specific structural testing on wood ribs to see what their fracture points are when tension is applied to various parts.

I don't have plans yet, so don't know the actual chord of the thing, but I do have a 40"x40"x40" 3d printer I call meterbot that we could leverage

[Aaron]

That sounds interesting, and as much as I like 3d printing, please don't 3D print (speaking polymers) ANY structural part of an airplane. The sun's UV is a powerful killer to long lasting outdoor machines like airplanes. I have stuck my hand in inside the wing cavity on a hot day and it's definitely hot enough to make concern considering PLA is fully manipulative at as cool as 200F.If it doesn't fail right away, it will surely fatigue and fail before you would like it to. Spruce sticks are cheap, easy, proven, and quite strong. I recall a test by Joe Spencer on Youtube at one point in time that displayed a hard to believe, massive amount of force (cant remember the number) required to break the LE wing rib in designed loading conditions. I am an advocate for experimental aircraft, utilizing recognized acceptable methods to aircraft construction. Build the structure safely, and play with 3D printing non-structurally. For example, my LE sports a 3D printed radio mount, coax antenna bulkead, and things of the like...

Besides, the rib building was one of my favorite parts, don't short yourself on that!

[the_imperfectionest]

Oh, yeah, PLA would certainly be a bad choice for anuthing like that!

And UV is certainly the other equal concern

[ironnerd]

Plastic (especially Plastic from a printer) may not be suitable for aircraft structure, but it can be used for tools. A 3d printed Rib Jig would be beneficial. Where I work, we have found that additive machining to produce accurate, stable, and fairly durable jigs and fixtures.

I don’t know what plastic they are using though (some of the big tools use some stuff impregnated with carbon fiber). We also have a printer large enough to park a small car inside (like a Chevy Spark).

[Aaron]

You are right on the money ironnerd. There are plenty of places in the building process for 3d printing to shine and save tons of time and increase accuracy. Just my personal opinion also that maybe not for actual aircraft structure. I know some gas turbine engine manufactures are experimenting with 3D printed components like fuel nozzles, LP nozzles, combustors etc that would otherwise be full of months worth of braze joints. That is super alloy 3d printing tho, which is a whole different ball game than the rag bags we fly :p