I'm a non-practicing aerospace engineer and building this kit has reminded me of a lot of theory that I've forgotten. The last kit that I built was a little over 20 years ago in my aircraft design class. I think it was the Chipmunk. We were allowed to make whatever design modifications we wanted (excluding changing the prop or rubber band), as long as we documented the design change, its intended purpose/benefits, the theory behind the modification, and any potential drawbacks. In the end, we were assessed on range and endurance. We also received feedback from the professor on our design modification. I think the most common comment was, "dramatically increases manufacturing complexity and cost at a marginal increase in performance". I think that most design engineers need to learn that lesson the hard way from their 1st manager.
Well I just finished the basic build on the 109 last night and had it balanced. So my son and I took it for a test glide this morning and it flew nice and level, with no discernible roll or yaw. I showed my 7 year old how to hand launch the plane and he did great the 1st two flights. Then he tried the 3rd time and said he wanted to make it go farther. He forgot what I told him, threw it like a center fielder and ended up launching it banked 90 deg. This was the result:
You know what, I really don't care. My son really loved the few glides he had, he learned something about flight dynamics, and he wants to help me repair the wing.
I do have one question and I apologize if this has been answered before. When doing some test prop winds, the glue bond between the prop shaft and the prop would break loose, unwinding the rubber band. I bent the shaft tip 90 deg., with no better results. What's the best way of securing the prop to the shaft?
Thanks,
Craig
