I'm done with creating a table model of an airplane. Now I'd like to create the same model of an airplane to be flown as an RC plane. I did some research and found a couple of airplane design that has successfully been tested and flown. Here's one of the examples that I found for free created by a company called Eclipson.
One of the front parts of the fuselage.
I converted the STL file into a slicer program called Simplify3D.
and test print just to see how it ended up look like. 
So I can't really figure out how they draw their skin for the fuselage in order to keep the weight at the bare minimum. From the slicer perspective, it looks like if you keep the thickness of the fuselage skin to below 1-2mm, the slicer will create a 1 layer for the outside and 2 layers for the inside print and the skin comes out at 1-2 mm but empty in between the slicer which keeps the fuselage lighter. That's my speculation. Any thought or advice or best practice when designing something like an RC plane in order to keep the weight as low as possible? I hope my question makes some sense. I'm attaching one of the STL files for reference. Thought?
Thanks, Paul Salvador. So what's your conclusion after you built that sketch yourself from the "Surface" perspective? Any thought?
Hello Le Dude... what Matt Peneguy shows and says about the nozzle diameters and filling and all the suggestions sounds very good.. and he's more into the 3D Printing than I. (I'm still learning and have yet to get a extruder style printer (I'm still considering a Ender 5 style )
My model idea was just to redo it with a 1mm wall and maybe add/subtract. but if the software can get you the desire wall.. that's the way to go!
Okay, I'll state this first before I get into a few things. You are very lucky that you've piqued Paul's interest, he's definitely a surfacing expert and can help with that. (Though I have no idea, what he was trying to point out with the image he posted.)
I'll try to answer your questions as best as I can regarding the 3D printing aspects.
I think there's a setting somewhere to adjust that wall thickness down from 1-2mm.
Your nozzle diameter is probably 0.4mm thick and because of that you should start thinking about your walls in multiples of that thickness 0.4, 0.8, 1.2, etc. Now it's not exactly that simple because the layers can be "squished" together if needed, but I think you get the point. You can set the wall thickness based on a multiple of 0.4mm and then there's an adjustment for how they are squished somewhere in there. I know where the setting is in Cura, but I'm not sure anymore for S3D.
Now that we understand wall thickness possibilities, what happens between the walls? That's called infill. You want to use as little infill density as possible (I've got prints using a different material with a density of 10% and they are very very tough and strong). Once again this has to do with strength, less infill means less weight, but also less strength. I think there's a slider in S3D for infill density in the middle of the main settings window. I'd slide it right on over to 10% and give it a go...What's this part cost in plastic to print this part? I'd guess a dollar or two. Through some denial and error you should be able to get a strong and light weight part. Do you have any metrics on how much it's supposed to weigh? One way to find that out may be to go to the website where you got the part and see what material it's supposed to be. If it's supposed to be carbon fiber, change the material in SW and see what the mass is. Cura and S3D should be able to tell you the expected weight, if it's close, print it out and weigh it.
Then there are other materials you can use. I've been trying to get PETG dialed in, but it's tricky. TPU may work because it's real tough (if you used it, you wouldn't have to worry about whatever you printed being damaged in a crash). But, if you are this new to 3D printing, it's probably best to stick to PLA for a while until you understand all of the settings and how to manipulate them to get the results you want.
And one last thing, Simplify3D is good, but I've switched to Cura. I have an old version of Simplify3D, but the new Cura is more capable than the old version. Because Cura is free, I think there's more good specific help on using it on youtube, YMMV.
And because I'm definitely not a 3D printing expert, I'll ping Frederick Law...Oh, and there's also Thomas Allsup, he's actually written articles about 3D printing.
Thanks, Matt Peneguy. Yeah, Paul Salvador has been a tremendous help during my learning process and of course, I'll always be learning but I'm at the stage where I'm comfy enough with Solidworks but not at the expert level as you guys, of course. As for material, I'll stick with PLA just because it's available and I'm using it for modeling. Even though I'll try to fly the model, but that's filament seems to be the go-to material for RC airplane folks. I have Cura and for whatever reason, I found their settings a bit more convoluted that the S3D but that's just me. Could also be because I'm just too lazy to try to learn it once I got comfortable with other products. Just like Solidworks. I have access to Fusion 360 and I still haven't tried to learn it more in-depth just because my patience level is not as high as it used to be. I just want it to work. Thus I'm sticking with Solidworks. I need to learn a bit more about using the surface and try to print it on 3d printer. My original design was all utilizing the surface but then I redesign it in extruded either boss or boundary boss so that I can manipulate the print from the slicer perspective. Not sure whether I do it right or not but it's printing alright. I'm just trying to figure out how those people who sell their RC print STL like Eclipson or 3DLabPrint does it when it comes to controlling the surface thickness. I can only get the free version of Eclipson but not the 3dlabprint.
..so, which RC model are you doing?
https://www.eclipson-airplanes.com/airplanes
Hi, Paul Salvador.
This is the one I use as an example for a 3D print airplane.
36" Northern Pike RC Airplane (It Flies!) by localfiend - Thingiverse
I've also reviewed the Eclipson plane and trying to figure out how they do it.
RC plane fuselage - Eclipson model Z by Eclipson - Thingiverse
Very Kewl!
I luv the sub structures within in the files! (image)
btw, his page at Thingiverse is beyond great with info!
So it was suppose to print skin as shell and add "frame" inside the shell.
..no... I manually moved them to show/expose them,.. the sub structures are within the shell bodies.
Interesting. Just looking at it, it appears they modified the infill for strength and weight, rather than just use one of the random printer infills.
I wonder if anyone has done an analysis on the weight/strength for some of the stock infills Cura or other slicers produce in comparison?...Maybe, if I find some spare time this weekend I could run some Xpress simulations...
Hi Paul Salvador.
Mind sharing the Rhino file that you created after you separated all those parts so I can learn it better how they do it? I'm still trying to figure out the best way to do it such as at which part, I need to add the internal structure and at which part, I don't really need it. Very intriguing for me on how they do it. Learning something new every day after seeing your dissection.
Matt
One note on wall thickness. When you start curving the walls like in the bottom of this part if you have a 1mm wall thickness you could get gaps between extruded lines within and between layers. So instead of remodeling it thinner it is better to go into the settings of the slicer and change the "skin thickness" and infill. Lowering the layer height reduces the problem.
Or use "adaptive layer".
You'll need to change layer thickness.
Cura has a +/- setting.
With 0.2 layer, +/- 0.1 will give you 0.3-0.1.
Depend on your nozzle size, 0.3 maybe too thick.
Find the layer range you want to use first: 0.3-0.05.
Set adjustment step: 0.05.
Find mid point of layer: (0.3+0.05)/2 = 0.175, this is layer thickness.
Set limit: 0.3-0.175 = 0.125.
Layer should not be more than 80% of nozzle size.
ie 0.4 nozzle, 0.32 max layer height.
If you read Eclipson's post in Thingiverse, they've detail on how to print it.
I'll follow what they recommend since they've made a flying plane.
As always with the problem of weight and strength.
You want minimum weight and enough strength.
You can print with different wall thickness, infill and test crash to find best setting.
You can model it in SW and run simulation..
Hi Frederick Law.
I guess that's the reason why I asked the question, right? Do I build the skin using the surface or do I use the traditional extrusion with defined thickness. I know the printing part can be controlled by the slicer but I've never use the surface and see how the slicer will treat it. I'll try to create something simple and see how the slicer treat it.