Ted is going to love this post... NOT! (Sorry old buddy)
I coined a saying many years ago that sums up my thoughts on this subject: It is possible to build a CL Stunt model too light... But no one has ever done it!
It may be the background in which I grew up (or at least got older...). In my youth I was privileged to have Larry Scarinzi and Harold "Red" Reinhardt as essentially big brothers. Red worked for my dad in our basement machine shop, and, wherever Red was, Larry would eventually show up; they were inseparable friends. Those men were two of the very best builders I have ever known. They produced extremely light and original models seemingly on a weekly basis. And, those models flew extremely well; they were fast, and tight turning. Lightweight awareness was pounded into me from that early age by those two, and by my dad as well. Later on my good friend and Stunt mentor, Bill Simons continued the lessons in light weight awareness.
I have always strived to produce the lightest Stunt models that I could, and I strongly believe that light is good, but lighter is better. (Are you still with me, Ted?) My best performing models - in all conditions - have been those that were the lightest ones. My 35-size Genesis had a wing loading of 9 1/2 ounces per square foot of wing area, and it remains to this day one of my best performers.
But, as Paul Walker hinted at above, it all depends on the power system and how it is tuned to run. We have all seen a light Nobler fitted with a Fox 35 and a 10 x 6 prop fly in our past I'm sure. Remember how it would whip up in the wind? The first loop would be fast, the second one faster, and the third one was ballistic. Remember how the Fox was running? I'll bet it was in a deep two-four setting. That allowed the motor to unload in the wind and accelerate the model progressively as the loops were flown. As the model sped up, the engine was into a two stroke mode, getting closer to its power peak and that only made the model go faster. A real-world example of this would be a car in high gear going down hill. If you were to push down on the gas, the car would continue to accelerate to a very high speed. But, if you were to put the car into low gear, it would not accelerate down the hill. The gearing would hold it back. In fact, if you continued to try and make the car go faster downhill in low gear you would eventually push the engine past its torque peak and it would be on the falling side of the horsepower curve, slowing the car down even further.
How you "gear" your model makes a ton of difference in how it performs in general, but specifically in windy conditions. High pitch and a two-four setting will allow whip up, while low pitch (low gear) will allow the engine to produce pulling power throughout the flight without the attendant whipping up in the wind. True, a lot of wind will affect any model setup in any "gearing" mode. But the low pitch-high RPM setup will be less affected. That was the whole reason we introduced the tuned pipe setup in the late 1980s (by
we I am referring to Dean Pappas, Richie Tower, Bill Werwage, and myself - although my involvement was more of being a "handle monkey" to give feedback on the various setups tried.
Okay, all of this relates how to this thread's discussion? If a light model is setup to be constantly pulling (low pitch- relatively high RPM), it will fly much different (and in my opinion much better...) than a somewhat heavier model setup to run in high gear (high pitch-low RPM). Many of you will agree with this, and many (still here, Ted?) will vehemently disagree.
Even before the advent of the pipe systems we were using this concept with the OS 40 FSR engines that we used in the mid to late 1970s. I can tell you that the ST46 powered Genesis that I used to make the 1978 World Team would not have been able to get through the wind encountered in England well enough to have allowed me to win that meet. The FSR was setup with a 4-inch pitch prop and it was set to run very high RPMs. It powered through the intense winds were encountered over there that year.
In closing this rant I will tell you that all my Classic Stunt models were extremely light and they all flew extremely well in all conditions. I had a 34 ounce Tucker (that still exists!) back in 1993, a 36 ounce Mackey Lark, and a 41 ounce Caprice. I would not have wanted any of them to have been heavier!
Okay, Ted, have at it...
Later _ Bob Hunt