What filament for airplane fairings

[cenpen]

Just bought an m2 to build fairings for an airplane project. What materials do you recommend to mqqke them out of. Any advice is appreciated

[Phil]

Unless this is for an Experimental or an RC, the answer is, "None".
You might run afoul FAA regulations, since the parts would have to be tested. I also doubt the process has been approved by the FAA. Boeing and some of the other big companies have just begun 3-D printing metal parts for airplanes.

[cenpen]

It is experimental

[zemlin]

I'm going to assume you're talking model airplane - but need more information.
Is this a flying model?
If flying, electric or internal combustion?
How large are you aiming to print?
Are there weight limits?

[willnewton]

For RC use with no heat sources nearby then PLA is fine, warmer areas might need ABS, PET, or polycarbonate. Fairings don't undergo much stress, so any material is fine.

A better idea would be to use a 3d print to make a mold for nose, propellor, or control linkage fairings. I used to mold and sell carbon fiber fairings, fuselages, and parts for RC gliders and can vouch for this process as a superior process to printing.

It depends on why you are making them. For yourself, do whatever you like. For sale, then you may want to look into stronger final materials that are faster to produce, such as a molded part.

[zemlin]

Even for a non-hot RC model I'd steer away from PLA because just a hot car can curl up PLA part.

[Phil]

I would suggest nylon, polypropylene, or polycarbonate. The polycarbonate is tougher and harder to print well. The nylon can be dyed to almost any color, will survive lots of flexing and vibration. Polypropylene is most flexible, resists moisture best, and least dense. (Nylon = 1.14 vs. Polycarbonate = 1.2 vs. Polypropylene = 0.946). Prices vary, but all can be found for similar price.

What sort of experimental? I would like to build an RV-7 someday.

[cenpen]

I guess I should have been more specific.. We are building a kit version of the Monocoupe Clip Wing.. Full size with a wooden wing and steel tube fuselage. Our goal is to get the body panels 3D printed as well as the fairings and wheel pants. The body we have been talking to Gigabot 3D printers and they can do in Carbon up to 36". The fairings and small parts we were going to try in house.. We also are producing a Warner radial engine (Yes full size) and want to make the intake pipes and maybe valve covers out of something that will hold up to 300 degrees.. Any suggestions?? It Is a niche project and we want to control the parts so we want to do them in house if possible.

Any help is much appreciated. Go to www.monocoupe.com to see the projects.

Thanks a bunch
-John

[ednisley]

something that will hold up to 300 degrees

That means the plastic's Tg (glass transition temperature) must be much higher than 300 °F = 150 °C to maintain the part's strength and shape under stress.

So none of the common 3D printable plastics will work: polycarbonate has a Tg around 300 °F and even Nylon 12 from Stratasys melts at 352 °F. Some nylon formulas have a high-enough Tg, but with a melting point far beyond the usual hot-end and extruder capabilities. An exotic filled nylon might work, if you could print it.

IMO the temperature rules out any material that consumer-grade 3D printers can handle…

[Phil]

John,

I have been researching this exact issue for some time now. PM me, and we can talk on the phone.