If you don't know exactly how to analyze a spar for your project and someone does it for you, it does not end there. You will need to analyze the root fittings and the structure where it joins the fuselage, any torsional effects etc etc. The TLAR approach ("That Looks About Right") is a recipe for suicide. Having said that, it is not impossible to learn this stuff, but you do need to do do some serious reading on the subject. Nobody here discourages new designs, or is trying to be a negative influence in any way, but not doing some basic maths can get you killed in this game.

---

"Aeronautical engineering is highly educated guessing, worked out to five decimal places."