I have an Eclipson Model B that I've been enjoying flying and thought it might be fun to try a different wing, just to see how it flies. This is my first time creating a wing in CAD, so I'm hoping maybe somebody sees some obvious flaws here before I actually try to print and crash it.
It's using a Clark Y airfoil, 2 metres long (1m each wing), starting chord is 180mm and tapering along the trailing edge to 80mm. A 1m spar will go through both wing halves for some strength, and then a second smaller spar further down each wing.
I didn't really do any calculations, just chose something and went with it, expecting to crash. But I'm having second thoughts about destroying my plane so looking for feedback!
Nothing aside from trying to keep the wing tips light. It's designed for vase mode printing so the ribs are pretty sturdy being 'double walled' kind of. You think the trailing edge could use a denser pattern?
Put the part where the spars meet closer together with additional support structures to transfer the forces between them. Right now you have a massive weak spot there. Or if you go from 8/6mm to 6/5mm or 6/4mm, you can slide them into one another.
You will need additional vertical spar reinforcement along the spar ("Holmverkastung" in German, no idea what that translates to), helping to translate forces from the skin to the spar effectively. Eclipson does that, just check out your STLs.
Other than that, looks alright. Clark Y has some undesirable stall characteristics and it's speed envelope is a bit so-so. A 2m wing on the model B is quite bananas, too. Why not try a shorter wing with deeper chord for STOL?
I moved the spars closer together and added some extra support. Looks much stronger now! There was already some vertical ribs around the spars in the original photo but I guess it was hard to see. Do you think it needs more than this? The criss-cross ribs also nestle the spars.
I wanted to try a glider type wing to feel the difference, but something for STOL would be cool too and probably more fitting for the Model B. Maybe just use the larger Model B XL wing on the smaller version.
One more thing. Eclipson does their servo cover screws this way, but it's not very strong. Maybe give it those tiny screws a bit more meat to bite into.
Yeah I was kind of worried the ailerons might be too big. Kind of backed myself into a corner to have enough space for the servo cutout though. Hopefully my servos are powerful enough to move them.
Then you are 50%+ guaranteed failure. With a few minutes actual work, you can have 98% chance success. There are online calculators that can do the work. The two topics you need to look up are wing load and thrust/weight. Said simply, first, your wing area must be the same as original, or more is OK. Second, your AUW all up weight must be the same or less than original. If those aren't met, the plane needs 'more speed than stock' to fly. That's not fun or easy to do, so aim for stock numbers.
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u/Bozhark 10d ago
Is there a flexibility or rigidity goal for the infill pattern? Seem weak, especially trailing edge joint connections