Design > Stunt design
The thousand ounce stunter
Curare:
This thread is a bit of a inversion of the zero ounce stunter, further egged on but the Tucker Special thread that seems to have been revivified recently. It's merely a hypothetical, but I'm sure the more insightful flyers may be able to glean some useful nuggets of information from it anyway.
So, given that we've assumed there is an "ideal weight" for a given airframe, (as I understand it to match flap area and deflection, line tension and cornering) how far could you go in terms of weight/wing loading?
If you did end up building a flying dumptruck, how would you augment the design and power to accommodate?
Obviously power requirements would be monumental, and one would assume you'd want enough wing area and flap area to be able to turn this lead sled. Obviously the airframe is going to get bigger, how big can you go? If you can't go too big, how are you going to get the lift required? Massive flaps? moveable leading edges? Funky doodads?
You'd have more than enough line tension to drag you off to Timbuktu, so how would you manage that? Fly slower? How slow can you go?
Ok, go!
Motorman:
Pilot prep
Dan McEntee:
I think something that is going to be close to what you are asking is in the thread in the "At The Handle " section, about the guy that has a Vector that weighs over 60 ounces. At 500 and some odd square inches, I don't think you can put enough horse power in it to get it to fly a pattern. More horse power means a bigger engine which means more nose weight which means more tail weight to balance. I have built and flown heavy airplanes and got reasonable performance from them, but there is a limit. I think the obsession over trying to get an uber-light model, or the "zero ounce stunt model" is one side of the pendulum arc, and "too heavy" is the other side. Every wing and airfoil has it's optimum wing loading and speed for generating the best lift, The math wizards can give you a formula, I'm sure. I have had two models that were 72 ounces or more. One powered by a ST.51 (a SIG Magnum) and the other a Cardinal powered by a ST.60. I got my first 500 point score with the Magnum, and won my first expert level contest with it. The cardinal was just a test bed mule to learn how to run ST. 60's It was bigger and most likely had more drag. Just going by memory, I think the Magnum flew better hands down at that weight. It was a bit smaller, more aerodynamically clean, and just better proportioned. I don't think the ST.51 put out more power than the ST.60, the Magnum just used the power available better. But if the weight of that Magnum started to push 80 ounces, pulling up into that first wing over would be interesting!
Type at you later,
Dan McEntee
Colin McRae:
--- Quote from: Dan McEntee on July 09, 2023, 10:57:46 PM --- I think something that is going to be close to what you are asking is in the thread in the "At The Handle " section, about the guy that has a Vector that weighs over 60 ounces. At 500 and some odd square inches, I don't think you can put enough horse power in it to get it to fly a pattern. More horse power means a bigger engine which means more nose weight which means more tail weight to balance. I have built and flown heavy airplanes and got reasonable performance from them, but there is a limit. I think the obsession over trying to get an uber-light model, or the "zero ounce stunt model" is one side of the pendulum arc, and "too heavy" is the other side. Every wing and airfoil has it's optimum wing loading and speed for generating the best lift, The math wizards can give you a formula, I'm sure. I have had two models that were 72 ounces or more. One powered by a ST.51 (a SIG Magnum) and the other a Cardinal powered by a ST.60. I got my first 500 point score with the Magnum, and won my first expert level contest with it. The cardinal was just a test bed mule to learn how to run ST. 60's It was bigger and most likely had more drag. Just going by memory, I think the Magnum flew better hands down at that weight. It was a bit smaller, more aerodynamically clean, and just better proportioned. I don't think the ST.51 put out more power than the ST.60, the Magnum just used the power available better. But if the weight of that Magnum started to push 80 ounces, pulling up into that first wing over would be interesting!
Type at you later,
Dan McEntee
--- End quote ---
Dan, I'm the guy with the Vector 40 brick. Right now at 64 oz and a 536 wing. 17.4 wing loading. I am a long way off from flying the full pattern. But working away and practicing at the different stunts with other models.
I just put a stock 46LA on the Vector (up from a 40LA) and will continue to fly it, but probably just fun and sport.
I did not build the model so can't speak to why it is so heavy. The model is beautifully built and finished. Not sure what the original builder was thinking. But at least I have learned one thing which is great. If one is not careful, covering and paint can weigh a ton!
Also, when I acquired the model, it was very tail heavy. I needed around 3-4 oz of lead up front to get a decent CG.
(One should surely stay away from a 17.4 wing loading!!)
Dan McEntee:
--- Quote from: Colin McRae on July 10, 2023, 03:34:44 PM ---Dan, I'm the guy with the Vector 40 brick. Right now at 64 oz and a 536 wing. 17.4 wing loading. I am a long way off from flying the full pattern. But working away and practicing at the different stunts with other models.
I just put a stock 46LA on the Vector (up from a 40LA) and will continue to fly it, but probably just fun and sport.
I did not build the model so can't speak to why it is so heavy. The model is beautifully built and finished. Not sure what the original builder was thinking. But at least I have learned one thing which is great. If one is not careful, covering and paint can weigh a ton!
Also, when I acquired the model, it was very tail heavy. I needed around 3-4 oz of lead up front to get a decent CG.
(One should surely stay away from a 17.4 wing loading!!)
--- End quote ---
Hi Colin;
I just couldn't remember your name last night!! Your Vector can be a part of a teaching moment as this goes forward. I liked Ted Fancher's articles on the "Zero Ounce Stunt Model" and agree with him. You can drive yourself crazy trying to get things to the uber light realm and have an airplane that is a real Flexible Flyer and have other durability issues. Your model can be the poster child for the other end of the spectrum. i think most guys report their Vectors, either kit built or ARFs to be on the heavy side, usually in the 50 pounce range. The Vector is about the size of the Nobler and they got built and finished in the same weight range, and the answer for the heavier airplanes became the ST.46 back then. The extreme case for that was the guy from Australia to our NATS with a Gieseke Nobler that had a PA.61 shoe horned into the nose, but I think that was a completely different matter and it wasn't excessively heavy except for the engine. With the majority of the Vectors coming in a bit porky, I just have to wonder if the design isn't a bit over built? I have a kit and an ARF stashed but have never examined them closely. My son has built one of each I think and his both came in on the high side.
Type at you later,
Dan McEntee
Navigation
[0] Message Index
[#] Next page
Go to full version