nice workmanship - and great commentary! these projects are great when the family gets involved. QQ - It looks like the orientation of your web is 90 degrees of the caps. Would it not be more structurally proper to put it in a 45 degree angle as to accommodate the stresses?
Good question! I ran this as a test. I used this section of wing for load testing. It proved to be strong enough, so I could simplify the construction by running the weave at 0/90 and hence cut material wastage. There are many factors beyond max aero perf, or max structural perf that can drive a design. One of my drivers is cost to build.
I'll assume that you are referencing the structural work - there is a lot of aerodynamic testing going on also. The short answer to your question is that my life will depend on the quality of my work, so I'm adverse to taking too many chances. The best answer would require a major technical paper and this isn't the place for that response. The basic issue here, I believe, is that most folks think engineering is an exact science - nothing could be further from the truth. Most aircraft designs, especially composite aircraft, have very generous safety margins worked into the design. Sometimes the margins reach a factor of 2. If I were to take that approach, this glider could easily weigh 150 lbs or more and I'm getting too old to run down hill with that much weight (a little humor). To achieve the weight goal for this aircraft (100 lbs) I must design with very narrow safety margins and that can be very risky. So, to mitigate those risks I build and test the components.
I hear you mate but don't overthink it, even the worlds largest and most advanced aircraft manufacturers use cheap materials like wood for mock ups and with sound design only engineer with actual materials the airframes deemed to fly or be tested under the same loads as flight statically - as a designer myself I can tell you your wing design is well established and proven aerodynamically and your structures are more than adequate to sustain man-carrying flight loads, my question was in response to your comments on a few occasions that these are not airworthy parts to which I say why the heck engineer them from 'airworthy' materials? The trick is to design smart engineering not over engineering and if anything I've seen fits the bill of smart design both aerodynamically and structurally it's your wing - I watch with eager anticipation
nice workmanship - and great commentary! these projects are great when the family gets involved. QQ - It looks like the orientation of your web is 90 degrees of the caps. Would it not be more structurally proper to put it in a 45 degree angle as to accommodate the stresses?
Good question! I ran this as a test. I used this section of wing for load testing. It proved to be strong enough, so I could simplify the construction by running the weave at 0/90 and hence cut material wastage. There are many factors beyond max aero perf, or max structural perf that can drive a design. One of my drivers is cost to build.
thanks to share all of the steps...I am learning more from you than my university studies
Thanks, that is one of the reasons I'm posting. I hope you will link in all your friends and fellow students.
Great to see good progress.
Thanks for the support!
I don't understand why these components are not airworthy parts? Why goto so much trouble and expense?
I'll assume that you are referencing the structural work - there is a lot of aerodynamic testing going on also. The short answer to your question is that my life will depend on the quality of my work, so I'm adverse to taking too many chances. The best answer would require a major technical paper and this isn't the place for that response. The basic issue here, I believe, is that most folks think engineering is an exact science - nothing could be further from the truth. Most aircraft designs, especially composite aircraft, have very generous safety margins worked into the design. Sometimes the margins reach a factor of 2. If I were to take that approach, this glider could easily weigh 150 lbs or more and I'm getting too old to run down hill with that much weight (a little humor). To achieve the weight goal for this aircraft (100 lbs) I must design with very narrow safety margins and that can be very risky. So, to mitigate those risks I build and test the components.
I hear you mate but don't overthink it, even the worlds largest and most advanced aircraft manufacturers use cheap materials like wood for mock ups and with sound design only engineer with actual materials the airframes deemed to fly or be tested under the same loads as flight statically - as a designer myself I can tell you your wing design is well established and proven aerodynamically and your structures are more than adequate to sustain man-carrying flight loads, my question was in response to your comments on a few occasions that these are not airworthy parts to which I say why the heck engineer them from 'airworthy' materials? The trick is to design smart engineering not over engineering and if anything I've seen fits the bill of smart design both aerodynamically and structurally it's your wing - I watch with eager anticipation
It's a privilege by the way to be chatting to the man himself! Keep inspiring and happy landings