Both the very top layers of the wingtips and the vstabs show the holes that I was seeing in Cura when I looked at the gcode. I held one up to the light so they would show in the photo.
My understanding at this point is that I could reprint the pieces using two perimeters (and I am guessing that the perimeter is the actual skin) which would double the weight of the pieces, or I could add additional top layers (in this case the top being the tips) by reslicing in Cura with the appropriate changes. Or I could use Simplify3d which has the capability to add perimeters to close the gaps in the upper layers, which is something Cura cannot do.
@localfiend Is my summary correct? If that is all true then would I expect anybody using that particular gcode to get the same result with the holes or will it vary from machine to machine.
Because these are airplanes the goal is to keep the wing loading as low as possible. Printing the wingtips with two perimeters (doubling the weight) might not be that big of an increase, but to do the same with the much larger Vstabs doesn't seem like the best approach. I am gathering that may be a justification to move to Simplify3D .
Some of the holes you can see light through are a part of the G-Code (I didn't feel like it was worth it to print the part any more solidly - this is an aircraft after all, and you can't see pinholes unless you're really looking). The other bigger holes are from filament failures. Either something was stuck to the nozzle, or there was an inconsistency, or both. Any tiny problem is multiplied on thin wall prints, especially on steeper overhangs.
There is another option available to you for the V-Stabs if you really care about getting perfect parts. You can use a program like meshmixer (it's free, and there are tutorials on youtube) to chop the STL into two sections. Then you can print the lower base at one perimeter, and the tip at 2. More of a pain, and adds another glue joint, but it's a way around buying Simplify3D.
You can tune out some of the nozzle catching an edge of a part with z-hop. Mostly the issue is that with PETG, stringing is almost impossible to completely get rid of. You can reduce your extrusion multiplayer, lower temps, and play with retraction settings to get things a little better for your spool of filament. That'l reduce some of the overheight problems that can crop up at retraction points.
You'll greatly increase your chances of impacting the strength of the part by doing that though. It all depends on if you enjoy tuning to that level of perfection.
And yes, the material on the inside of the fuselage cap is support material. Grab it with a pair of needle nose pliers and pull it out. Depending on your filament, this can be easy, and come out in one pieces, or a little more difficult.
Also, to answer a previous question, you can print wider than than your nozzle size. E3d Nozzles (and most others, but not all) like your Prusa has, have a flat bottomed nozzle. You can increase print width until you start reaching the edge of that flat spot. With a .4mm nozzle, you're generally okish until you start going past .55mm print widths. Keep in mind that increasing the width, means more plastic, and more weight.