Classic and N-30 question

[Joe Ed Pederson]

I reviewed the Classic Rules on PAMPA and N-30 at Stunthangar.

It would seem to be OK to change a Classic or N-30 from a longer inboard wing panel to and equal length wing panel. I'm not thinking of the Palmer Hurricane, that would be glaringly obvious, but what about the Gieske Nobler that has a 5/8" longer inner panel, and the '57 Green Box Nobler that has 7/8" longer inner panel?

Am I correct in thinking it would not violate the rules (or the intent of the rules) to change a design that had a longer inboard wing to and equal panel wing?

Joe Ed Pederson

[Dan McEntee]

   I would consider it an aerodynamic change and not allowed. A lot of more modern models have similar wing offset. In my mind, if it was good enough form Mr. Gieseke, it should be good enough for me! When you get time, wing offset has been discussed a lot on the forum for both modern and earlier designs. There is just no need for the All American Senior type of offset these days!
  Type at you later,
  Dan McEntee

[Dave_Trible]

I wouldn't change them.  While I prefer equal panel wings and do that on my regular stuff,  obviously the unequal panels can be trimmed to fly fine.  The differences are actually subtle and not worth the effort to change-and yes a change should be outside the rules,  however I've not seen any judges carrying a measuring tape and a set of plans to check anything.  To me, personally,  if you are wishing to duplicate an airplane and event from another era why change anything (including power plants )?  Typically my classic ships have only one concession to history-nylon hinges- so that I'm not having rotten cloth hinges to replace at some point like in the old days.

Dave

[Brett Buck]

   I would consider it an aerodynamic change and not allowed. A lot of more modern models have similar wing offset. In my mind, if it was good enough form Mr. Gieseke, it should be good enough for me! When you get time, wing offset has been discussed a lot on the forum for both modern and earlier designs. There is just no need for the All American Senior type of offset these days!

    That is definitely not in the spirit of the rules, however, this is intended to be handled by fidelity points. I see no provision in the rules for disqualifying anyone for anything.

      I would add- removing all the asymmetry to make it equal span is very unlikely to make it fly better (aside from bizarre special cases like the All-American) and it certainly is not worth it or even a good idea in the case of the Nobler - 7/8" is plenty close enough to the optimal 1/2". You might have to add a tab to the outboard flap but other than that7/8" is definitely in the ballpark.

    I am not sure where the notion that everyone now uses equal-span wings comes from. While I haven't been out measuring them, almost all modern airplanes use moderate amounts of asymmetry (maybe 1/2" - 1 1/4"). My current airplane is 1 1/4", up from the previous 1", seems to make very little difference.

   Equal-span wings seem rather rare, it was a "thing" back in the 80s in New Jersey, and everyone has tried it at one time or another, but the right amount is about 3/4" and it is not at all critical.

     Brett

[Ken Culbertson]

Brett sums up my position on the rules.  Around here no one would notice unless you told them.  As to the offset, I have never been able to notice much difference.  Even the oft used example of the All American which I have flown about 1,000 times as a teenager fly's pretty flat once airborn.  Over simplified, the fuselage is just tip weight.  If you don't think that check out the picture of Doug Moon's plane running out the tank after shedding the outboard wing on another thread.

https://stunthanger.com/smf/open-forum/control-line-cutaway/msg662122/#msg662122

Keep it per the plans if it is not too late.

Ken

[Joe Ed Pederson]

Thanks, everyone.

I'll leave the wing panels as called for on the plans.  That will save the time of redrawing a wing panel.  And I don't want to violate the rules or even the spirit of the rules.

I got the idea from watching a Windy U Master 882 (Flap Horns).  Windy said he had a devil of a time trimming asymetrical wings (that East Coast thing Brett was probably referring to).  I have a dickens of a time trimming models and I thought why complicate things any more than they have to be complicated.

But Windy was a snapshot in time and he might have changed his mind later on and I just haven't run across him saying that in a later video. 

Joe Ed

[Dan McEntee]

Thanks, everyone.

I'll leave the wing panels as called for on the plans.  That will save the time of redrawing a wing panel.  And I don't want to violate the rules or even the spirit of the rules.

I got the idea from watching a Windy U Master 882 (Flap Horns).  Windy said he had a devil of a time trimming asymetrical wings (that East Coast thing Brett was probably referring to).  I have a dickens of a time trimming models and I thought why complicate things any more than they have to be complicated.

But Windy was a snapshot in time and he might have changed his mind later on and I just haven't run across him saying that in a later video. 

Joe Ed

    As time marches on, trends change and people come up with what they think are new ideas. But the laws of physics remain constant and in force all the time! The outboard wingtip flies farther and faster than the inboard wing tip. The inboard wing tends to generate less lift as the outboard wing as a result. That's one reason for offset. Wing offset, flap sizes and differentials and other factors have been an interesting subject of discussion for a long, long time and will remain so I think. If you think the Green Box and Gieseke Nobler are different, you should check out the plans and kit for George Aldich's Original Nobler!! I think it has something like 2+ inches of offset, and from the quick look I had and the Brodak kit ribs and such, the ribs for each wing are different! If I get the time I want to compare the kit plans to a set of plans I got directly from George at VSC one year and see how they compare. And then there is Bob Palmer's differential flap horns that move the inboard and outboard flaps at different rates!! I'm not sure which was what in that case!! It's all part of the hobby and pretty interesting.
  Type at you later,
   Dan McEntee

[john e. holliday]

I still don't understand why people would not stick as close as they can on building a plane for an event.  Really I guess it those that want another dust collector to put on the shelf.  Granted in some areas a builder will have to go electric so he can fly without any problems from those that can't stand to see some one doing something for enjoyment.  Ti me it was great to get a plane built for an event an have success with it built box stock.

[Brett Buck]

I got the idea from watching a Windy U Master 882 (Flap Horns).  Windy said he had a devil of a time trimming asymetrical wings (that East Coast thing Brett was probably referring to).  I have a dickens of a time trimming models and I thought why complicate things any more than they have to be complicated.

But Windy was a snapshot in time and he might have changed his mind later on and I just haven't run across him saying that in a later video. 

    Windy's trimming issues were not a function of the asymmetry, and neither are yours. Trimming is one of those things that you can learn, but it does take a good grasp of the dynamics involved to make sense of it, and no one ever masters it completely. Windy was not known as a master trimmer

   The Nobler is one of those airplanes that reflected the thinking at the time (1952 and 1957!) and worked around the limitations of the day, particularly the limited power. The limited power led GMA to "manufacture" line tension through lots of yaw and roll intended to help the overworked Fox 35 and other similar vintage engines. but GMA was also noted for flying "smoothly. The Nobler article was not titled "Nobler,", it was titled "Stunting Can Be Smooth".  He did this in ways that are definitely not what the rule book says, and would not get you too far today. If you fly "smoothly" in the sense he understood it, these roll and yaw motions will not cause many detrimental effects. It will start to kill you if you attempt to fly competitive flights today, the first hard corner will upset the airplane and with a Fox, it might not recover completely until you get into level flight.

    Note that I say "hard corner" - but set up as shown on the Green Box plans, it won't turn a hard corner, it can only fly "smooth". To "fix" it, you need to make a lot more changes than the asymmetry, like cutting down the flaps or the flap travel, and/or increasing the size of the stabilizer. If all you want is a good flying plane, go right ahead, but for Classic, that's missing the point not to mention not the intent of the event.

    Nostalgia 30 is a different story, an Impact is perfectly legal for that, SV-11 is legal for that, and maybe the Trivial Pursuit (either legal or about to be), so you compromise nearly nothing.

     Brett

[Joe Ed Pederson]

   The Nobler is one of those airplanes that reflected the thinking at the time (1952 and 1957!) and worked around the limitations of the day, particularly the limited power. The limited power led GMA to "manufacture" line tension through lots of yaw and roll intended to help the overworked Fox 35 and other similar vintage engines. but GMA was also noted for flying "smoothly. The Nobler article was not titled "Nobler,", it was titled "Stunting Can Be Smooth".  He did this in ways that are definitely not what the rule book says, and would not get you too far today. If you fly "smoothly" in the sense he understood it, these roll and yaw motions will not cause many detrimental effects. It will start to kill you if you attempt to fly competitive flights today, the first hard corner will upset the airplane and with a Fox, it might not recover completely until you get into level flight.

    Note that I say "hard corner" - but set up as shown on the Green Box plans, it won't turn a hard corner, it can only fly "smooth". To "fix" it, you need to make a lot more changes than the asymmetry, like cutting down the flaps or the flap travel, and/or increasing the size of the stabilizer. If all you want is a good flying plane, go right ahead, but for Classic, that's missing the point not to mention not the intent of the event.

    Nostalgia 30 is a different story, an Impact is perfectly legal for that, SV-11 is legal for that, and maybe the Trivial Pursuit (either legal or about to

     Brett

Brett,

I appreciate the extensive description about how the Nobler flies.   I often hear people say, "The (name of the model) flies "great/fabulous" or the like.  It would be much more enlightening to have people describe the strengths and weakness of the model as you did with the Nobler.

Please indulge another question.   If there are Classic designs that can turn 'hard' corners or pretty close to hard corners, could you (or others reading this) name a few?

Joe Ed Pederson

[Ken Culbertson]

If there are Classic designs that can turn 'hard' corners or pretty close to hard corners, could you (or others reading this) name a few?

If you have access to Winn Paul's book you only have to go to the 1968-69 Nats photo's to get a list.  The ones of those I am familiar enough to say that they could turn close to a "tight" corner by today's standards would be the Shark and the USA-1 followed closely by the Novi IV and the Gieseke Nobler and the Formula S.  Keep in mind that tight does not mean clean.  None of them will do what today's planes will do, they simply did not have the power.

Ken

[Joe Ed Pederson]

If you have access to Winn Paul's book you only have to go to the 1968-69 Nats photo's to get a list.  The ones of those I am familiar enough to say that they could turn close to a "tight" corner by today's standards would be the Shark and the USA-1 followed closely by the Novi IV and the Gieseke Nobler and the Formula S.  Keep in mind that tight does not mean clean.  None of them will do what today's planes will do, they simply did not have the power.

Ken

Thanks, Ken.  I've always liked the Shark.

I detect a common theme in your post and Brett's: lack of power in the baffle piston engines available in the Classic era.

This will probably stir up a hornet's nest, (and this war may have been fought a thousand times before I got back into stunt in 2018) but if the rules for Classic and the intent of the rules is for us to compete with the same "equipment" (my word) that was available in that period of time, then it would seem to me that using more modern and more powerful schneurle engines or electric motors more powerful than the baffle piston engines available before 1969 should be as out of bounds as enlarging the stab/elevator to 25% of the area of the wing.

 Anyway, after considering the posts above, once I can fly the whole pattern I plan on competing in Classic with models that are built to the dimensions in the plans, using only IC motors available before 1969, and to go one further, flown on steel lines.  In other words, fly with what the pilots of that era had available to them (with the exceptions of not having to build with Ambroid glue, and other such things that don't effect the flight characteristics).

I'll duck now.

Joe Ed Pederson

[Ken Culbertson]

In other words, fly with what the pilots of that era had available to them (with the exceptions of not having to build with Ambroid glue, and other such things that don't effect the flight characteristics).

I'll duck now.

No need to duck.  I agree with you in principal on Classic but the event has evolved to where it is and modern power is allowed.  My Fox 35 powered Classic (my own design that I flew in the 60's) is now powered by a BadAss 3515 which is the equivalent of a piped IC 75.   I admire you going Old School.

Ken

[Jim Svitko]

I have a copy of the original Coyote article, by Dick Mathis.  In this article, Mathis built the Coyote with equal span wings, and no engine or rudder offset.

Mathis was a master at light construction.  Minimal amount of wood, and usually finished in colored Japanese tissue and clear dope.  He claimed a finished weight of 30-35 ounces.  Powered with an Enya 35, he did not need to manufacture line tension.  But, a plane with that much wing area, and so light, I bet it was a handful in breezy conditions.

[Brett Buck]

I have a copy of the original Coyote article, by Dick Mathis.  In this article, Mathis built the Coyote with equal span wings, and no engine or rudder offset.

Mathis was a master at light construction.  Minimal amount of wood, and usually finished in colored Japanese tissue and clear dope.  He claimed a finished weight of 30-35 ounces.  Powered with an Enya 35, he did not need to manufacture line tension.  But, a plane with that much wing area, and so light, I bet it was a handful in breezy conditions.

The problem with the Coyote is that the airfoil is super-pointy and it is not that easy to just sand it more aggressively to attempt to fix it within the rules. All of the very light elevator-only airplanes we tried had the "flies like a kite" effect, particularly the original prototype-sized Doctor, which had some absurdly low wing loading. The published plan, I think, was smaller somehow. It was AMAZING in light air, and you could certainly fly it accurately in any wind you could stand up in, but with absolutely crazy "crab angles".

Flying Ted's Coyote/25FP back-to-back with the 26-ounce plywood-rib Skyray/20FP, the Coyote could turn slightly better (limited by the stalls) and tracked better, the Skyray was more secure on the lines and could turn as hard as the elevator travel would allow. Unfortunately, this wasn't very good the way I had it set up at the time, I subsequently enlarged the elevator and still later added travel. With the mods, I probably prefer the Skyray, it's more solid on the lines, even when  it got a balsa wing and dropped 6 ounces.

  I would also add that era Enya 35 is probably a wash or a very marginal step up from a Fox 35 in terms of performance (although it was light-years ahead in workmanship). The Fox was/is a decently powerful engine by 50's-60's baffle-piston stunt engines standards, it is only weak compared to  bigger baffle piston engines and then the far more powerful schneurle engines.

      Enyas of that vintage were not consequentially more powerful than any of the others, ran the usual 10-6 at typical revs. The reason I ended up having a Skyray kit in the first place was to get parts to rebuild another fliers Skyray after I got in the "coffin corner" and crashed it with it's pretty wimpy Enya 29 of the same era.  This was why I started the "small engine experiment" in the first place,. A  25LA or 20 FP is a be a very dramatic improvement on this size airplane

     One of the very first small engine tests were with Ted's (also very light) Coyote with a 25FP, this was the one where we discovered that the muffler baffle was very important (it was missing from Ted's muffler) and that the 20 was a much more tractable engine for stunt. The 25FP would just home in on "slightly too fast", just like a 40FP, but not to the same degree.

      Brett


p.s. I think Mathis solved, or attempted to fix, the stalling issue, with a later version ("Excalibur"?) that had flaps. Reportedly it was not a particularly good airplane. Had the LE been more reasonable on the Coyote, there was *no way* you were ever going to stall it, even with 35 baffle-piston engines. So, trying to solve the problem without actually diagnosing it. Same problem with the Strega ARF, and a lot of Windy's "giant flap" airplanes.