Kindly define a “heavy” airplane.

[Ken Culbertson]

......From some perspectives that might be true, but given what I know about your situation, I doubt that any of them are heavy enough to make any significant difference. It is very rare indeed to find a stunt airplane that won't fly simply because it is too heavy.......
[/quote
The other issue, particularly for newer flyers, is over controlling when the plane is up over 45deg.  Make a mistake, and instead of whipping the plane through, damn the score, they way over control the plane to try to make it go somewhere it can't go.

You've gotta know when to  quit and sacrifice what will obviously going to get a lousy maneuver score.

This is really overlooked by a lot on fliers.  You have to know the limits of your plane, and the only way to know it is to push it to it's limits at a safe altitude.  I rarely see anybody, even our other local experts do that anymore. I cringe when I see a flier try and save the shape of a maneuver when the plane is already outside it's envelope and the OH8 is the worst.

Ken

[Avaiojet]

An airplane has to weight what it weighs to do what it needs to do no more, no less. Airplanes that are built too light and need weight to fix CG issues are not built right. Airplanes built too light and wiggle don't do what they need to do. Airplanes built with stuff to make them stronger "because they need it" are too heavy. If the airplane is strong enough to survive what it needs then it is good enough. Adding carbon fiber, a fad favorite of many, doesn't do anything but add fancy and weight for bragging rights. Manage the needs and when it's finished it will weight what it needs to and that is that. I very rarely weigh my airplanes unless there is a minimum weight requirement for the class. What they weigh is basically irrelevant provided the CG is correct and they are strong enough for the mission.

Yes, build the model for the purpose. Absolutely.

I know of a model at 42" in span and weighs 82 ounces. No, not one of mine.

That certainly sounds heavy, however, without seeing the model and the building efforts, plus the many functions which the model has, full blown scale BTW, 82 ounces can be considered "reasonable" for this particular model.

I don't care about weight either. Choose wood correctly.

I have no models over 55 ounces, and it's just the way they came out. One, the first one I sold, was a bit heavier, the buyer will only use it for static display.

[Gary Dowler]

Want a heavy CL model? I know a guy who has built a scale F-84. I want to say about 1/12 scale. 45” wing. This was made for authentic scale. A little over 400sq in of scale airfoil wing, and with battery it tips the scales at 138 oz!!!  Imagine a 7.5lb Ringmaster…..  Cockpit has every last lever, button, switch, etc.  working Holographic gunsight! 
Power is twin electric motors, one fitted inside each wing tip tank.  Yes, it’s flown.  It’s quite impressive, but it flies terribly due to the weight. Far too fast.

Gary

[Shorts,David]

The last one was 72 oz with a 75.  I feel that was the too heavy. How do I know?  With proper trim and good solid speed for consistent maneuvers in hot conditions like we normally fly in the plane would "slide" into the intersections and "slide" through corners.  It was way way worse in high humidity conditions. After exhausting many different avenues with this model I retired it. 

Like Brett and Ted and others pointed out, I be I would still find it to be the best flying plane I'd ever flown.

[Avaiojet]

Want a heavy CL model? I know a guy who has built a scale F-84. I want to say about 1/12 scale. 45” wing. This was made for authentic scale. A little over 400sq in of scale airfoil wing, and with battery it tips the scales at 138 oz!!!  Imagine a 7.5lb Ringmaster…..  Cockpit has every last lever, button, switch, etc.  working Holographic gunsight! 
Power is twin electric motors, one fitted inside each wing tip tank.  Yes, it’s flown.  It’s quite impressive, but it flies terribly due to the weight. Far too fast.

Gary

He could have cheated on the airfoil, might have been a small benefit.

Scale and odd ball models. Go figure.

[Brett Buck]

Want a heavy CL model? I know a guy who has built a scale F-84. I want to say about 1/12 scale. 45” wing. This was made for authentic scale. A little over 400sq in of scale airfoil wing, and with battery it tips the scales at 138 oz!!!  Imagine a 7.5lb Ringmaster…..  Cockpit has every last lever, button, switch, etc.  working Holographic gunsight! 
Power is twin electric motors, one fitted inside each wing tip tank.  Yes, it’s flown.  It’s quite impressive, but it flies terribly due to the weight. Far too fast.

     I hesitate to criticize people doing something different, but I have seen a few scale plans that used yards of plywood, and as far as I could tell, for no particular reason - balsa would have been perfectly fine for the application.

      Brett

[Brett Buck]

This is really overlooked by a lot on fliers.  You have to know the limits of your plane, and the only way to know it is to push it to it's limits at a safe altitude.  I rarely see anybody, even our other local experts do that anymore. I cringe when I see a flier try and save the shape of a maneuver when the plane is already outside it's envelope and the OH8 is the worst.

    Yes, I had an off-line discussion about that recently, one of the skills to learn is how to adjust for the way the airplane is flying in such a way to minimize errors.  That's a problem a lot of people, particular people who want to treat stunt like there were objective measurements (of things like corner radius and maneuver angular dimensions).

    You cannot just jam the corners regardless of how the airplane is reacting, or force it into fixed dimensions regardless - unless you want to lose a lot of stunt contests. That's when you hear experienced fliers give coaching like "you are flying too hard" or "hitting the corners too tight" (despite the specified radius being, effectively, 0) - because while you might be getting that one thing right, you are making other, far more important, mistakes.

       Talking about it is a lot easier than doing it, of course, but this is one of those skills that you can only develop by actually flying the airplanes.

      Brett

[Dan McEntee]

     I hesitate to criticize people doing something different, but I have seen a few scale plans that used yards of plywood, and as far as I could tell, for no particular reason - balsa would have been perfectly fine for the application.

      Brett

     I worked part time at a local hobby shop for 35 years or so, and consulted on more construction projects than I can remember. I have always flown control line, free flight (both indoor and outdoor competitively)  and R/C soaring competitively. but had many friends and customers that flew all the other disciplines, so I was pretty well versed in the ins and outs of the hobby. One thing I learned early on is that the designer of a model that had been kitted pretty much had everything figured out or it would not have been put into production, and when in doubt, build it like the plans and instructions say.  When helping people with questions of trouble spots in construction, most people could be convinced that they needed to trust the designer, and for at least the first example of a model they built, build it per plans and instruction. I remember two specific customers that could not be reached, and both had that "fighter jock" attitude because they were both ex-fighter jocks! And neither had ever built any kind of flying model before. The first one picked the Top Flite P-39 .60 size scale kit as his first model and could not be talked into any kind of trainer. As he got started with the construction, he started to "redesign" the airplane!  This gentleman was also an engineer at a local, large aircraft manufacturer and he started to find fault with just about everything in the construction of the model. His main concern was that things weren't strong enough and started to replace balsa with plywood. I cautioned him on this and pointed out the obvious to him but to no avail. He ended up with a lead sled that actually would not rotate and get airborne. I got the story second hand from one of the club members that helped him with a preflight check and was going to put the maiden flight on it, if it ever got off the ground!  This club member was very experienced and was smart enough to not push things, and the owner left the field with his model intact but never came back. The other was local business owner of a jewelry store and a former A-4 pilot. This was a similar story, but at least I convinced this gentleman to start with a SIG Kadet . The progression was similar, and construction was completed, but as it was nearing completion, he was starting to doubt it's success himself and decided to just upgrade the engine to a .60 to handle the extra weight. I didn't get to see this attempt either but it went nearly the same. The difference was this model got off the ground but shouldn't have! The pilot was a little less experienced and he fought it every inch of the way until it stalled and rolled in. This gentleman came into the shop a few weeks later and purchased another Kadet, pulled me aside , and thanked me for the help and promised to build the new one correctly!. I don't know if he ever did or not, because I never saw him again. A few similar experience but these were the worst I could remember.
  Type at you later,
    Dan McEntee

[kevin king]

I saved an ounce and a half using balsa motor mounts on my Nobler.

[Ken Culbertson]

I saved an ounce and a half using balsa motor mounts on my Nobler.

I can guess you got the wood from HobbyTown.  That is the good thing about the quality of balsa today.

Ken

[Ted Fancher]

An airplane must be as light as possible but not much lighter.

Hmmm, Paul?  If you were capable of building a zero ounce stunter what would the line tension be at 5.25 seconds per lap...hmnmmmm???  (Can't explain the mysterious "n" in the preceding "hmmmmmm"??)

Ted "Ton of Bricks Stunter King" Fancher

[kevin king]

Even a brick will fly. But a light brick will fly better than a heavy one...

Bob Hunt

Does a ping pong ball also fly better than say, a baseball?

[kevin king]

Heavier stunt ships will blow the hats of the judges when it goes by, upping your score because the sun is now in their eyes, so they cant see you blew an intersection.

[john e. holliday]

DOC's definition of heavy plane: It plows ground or rolls on pavement until out of fuel,

[Avaiojet]

Some years ago, actually an aeronautical university project,

They built a model of a Beechcraft t-34 Mentor. 100% scale with no modifications.

That is, exact airfoils and all dimensions true to the scale.

I don't remember the size of the model but what I do remember was the take off roll before rotation. It was 300 ft, before the model was able to fly.

I don't remember the weight.

[944_Jim]

Unfortunately I know this answer too well, yet I don't know how to forcast it and make the required "dietary considerations" for my planes.

1) Performs altitude/directional changes poorly
2) Spectacularly lands on any part not including wheels, which are the only parts that can be recycled
3) Leaves impact scars in pavement, or requires rakes and shovels to repair sod
4) Results in reclaimed storage space "in the hanger"

 

I've got to discover a less destructive way to measure!