News:



  • March 28, 2024, 02:14:11 PM

Login with username, password and session length

Author Topic: How Big is too Big?  (Read 1760 times)

Mike Griffin

  • Guest
  • Trade Count: (0)
How Big is too Big?
« on: October 24, 2014, 06:46:42 PM »
I received an e mail a few days ago from a fellow who was asking me about some of the past kits I had done and whether they were still available, and by the way they are.  He really brought up an interesting point in the e mail about the size of of current day stunters.  He was interested in my past kits because they were kind of middle of the road as far as size goes and that he and some other members of his club had been talking about how large stunt ships have become in vogue the past few years.  His contention was that he smaller ships,  with wingspans somewhere in the mid to upper 40's were better handling stunt ships than the bigger planes.  I realize this may be looked at by some as being somewhat of an ambiguous  statement but I was wondering if other stunt pilots felt that there has to be a happy medium when it comes to the size of a stunt ship in relation to how it flies. 

Thanks

Mike

Offline Motorman

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 3243
Re: How Big is too Big?
« Reply #1 on: October 24, 2014, 07:14:29 PM »
Anything bigger than 600 Sq. In. won't fit in my back seat. Besides that I'm happy with that size. I don't want a big airplane that pulls hard.

MM

Offline Randy Cuberly

  • 21 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 3674
Re: How Big is too Big?
« Reply #2 on: October 24, 2014, 07:51:00 PM »
It would seem from my experience that 650 to 700 sq in wing with weights in the 56 to 65 oz range, is just about ideal for flying our current pattern.
If you look at most of the winning stunters in the past 20 years or so, certainly most of them fall into that category.

My friend Jim Hoffman from phoenix summed it up with this half hearted comment when I inquired about why he didn't seem to fly his very good flying Nobler in classic competition..."Big airplane big score...Little airplane little score!

In reality I believe the larger airplanes in the range mentioned above are easier to fly well...especially when the wind blows.  They also seem to be easier to trim.

Personally I typically lean to about 650 sq in 65 powered piped airplanes.  There's a reason why most top experts fly airplanes in that class range...It's no an accident that most do!

Randy Cuberly
Randy Cuberly
Tucson, AZ

Offline Steve Helmick

  • AMA Member and supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 9920
Re: How Big is too Big?
« Reply #3 on: October 24, 2014, 07:57:19 PM »
Mid to upper 40-inch span means around 500 sq. inches, doesn't it? Seems too big for a .25, a little small for a .40, maybe about right for a Fox .35, and too small for electrons.

After flying an SV-11 (690 sq.in.) for several seasons, I am liking the Eagle, which is about 638 sq.in. with the .46VF, tho it has nothing to do with how they fly. More like how they fit in the truck and how they go through the shop door.  H^^ Steve
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Mike Griffin

  • Guest
  • Trade Count: (0)
Re: How Big is too Big?
« Reply #4 on: October 24, 2014, 08:17:06 PM »
When I moved to Macon, GA for five years because of Katrina, Bob Dixon, Tom Dixon's cousin, flew expert and won many a contest with that old worn out red nobler with a Fox .35 on it.  Of course that might have been something to do with the pilot also.  Bob and I were the only CL flyers in GAMA.

Mike

Offline Tim Wescott

  • 2016 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 12804
Re: How Big is too Big?
« Reply #5 on: October 24, 2014, 10:39:55 PM »
... and how they go through the shop door.

Really, Steve -- you should open the door before taking an airplane through the doorway.  Anything else just makes a mess.
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline Air Ministry .

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 4978
Re: How Big is too Big?
« Reply #6 on: October 25, 2014, 07:19:43 PM »
 :P



 :-\



 :)



was a old ' Motorcycle ' cartoon with a doorframe with a low wide cutout. " are you the bloke that built the transverse 16 in his front room ."  %^@

ANYWAY . the olde 4 foot spar or trailing edge suckers , built at 36 ounces ( if your lucky ) with a unsilenced Fox 35 or the like , tend to be RELAXING to fly .
These days youd go for a silenced 40 . Knocking it up on a Friday night , or over the weekend ; youd be lucky to get it at 40 ounces , without neurosis or
excess use of braincells or dollars . unless your Mr monocote . :-X . This'd be about the max weight youd get a tight turn from a thin wing thing from .

Some people go flying for the ' buzz ' , some to chill out , and some for the social thing , or to escape the domestic bliss . n~

For a relaxing / low intensity trip - a light well powered straight sucker on 60 ft. of wire , should cut the mustard . Then theres the economies etc .
Cant see most plastic holding something firm enough for good performace in indifferent air .

Bigger ( 60 in odd ) schneurle things can take a bit of wire , & hold themselves out ; but the level of primary attention to the task is usually paramout .
While they'll fly accurately they need to be flown accurately where the olde 35 size suckers flew themselves a bit more . ? ? ?  >:( maybe . My perception anyway.
Though they all want watching in the bottom hourglass corner  >:( for some reason . Ft. per second etc and so on .
« Last Edit: October 25, 2014, 07:46:51 PM by Matt Spencer »

Online Robert Zambelli

  • 23 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2913
Re: How Big is too Big?
« Reply #7 on: October 25, 2014, 07:27:30 PM »
Really big!!!

  Bob Z.

Offline Air Ministry .

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 4978
Re: How Big is too Big?
« Reply #8 on: October 25, 2014, 07:54:49 PM »
Clint Eastwood with P-38 .  :-\ ;) bigas the F A I ' ll let ya go , nowadays . Weighing 5 ton it wallowed when the NSW crowd saw it , but changing from 9 x 6 to
10 x 4 3 blades got it doing the aerobics o.k. . Figure two good 25s'd fly it - if built light . Theroy was the wings should stay on at the ton If I put R.C. gear in it .



sitting in the rafters a bit chopped about . Only got six OS 35s now ,
though two should be enough . Will do moulded booms & maybe
nacelle .Finally figured rubber band retracts ,. for lite weight .

Offline Larry Renger

  • 21 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 3995
Re: How Big is too Big?
« Reply #9 on: October 25, 2014, 09:10:55 PM »
S$&3w the judges, I don't care to fly models bigger than a .15! I may make an exception for an OT Ringmaster with Fox.35. I flew really badly (for me) at GSSC and did 475. With that plane I have done over 500.
Think S.M.A.L.L. y'all and, it's all good, CL, FF and RC!

DesignMan
 BTW, Dracula Sucks!  A closed mouth gathers no feet!

Offline Luiz Carlos Franco

  • Trade Count: (0)
  • Ensign
  • **
  • Posts: 32
Re: How Big is too Big?
« Reply #10 on: October 26, 2014, 07:40:34 AM »
Think about two planes geometrically identical and of similar construction, however one is 2 times bigger then the other.

Wing area of the big plane would be L^squared = 4 times the area of the smaller one.

Weight correlates with volume so the larger plane would be L^cubed = 8 times heavier than the smaller one.

Wing loading would be weight/wing area = 8/4 = 2 times greater fot the big plane.

Cross sections would also be greater by 4 times and efforts too would be 8 times greater so stresses would also be double, i.e., the big plane is 2 times weaker.

Does theory correlate with practice in this case?

Is that why big planes use much bigger engines. Compare a Nobler with a 35 to a Thundergazer with a 75.

Regards

luiz

Offline Air Ministry .

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 4978
Re: How Big is too Big?
« Reply #11 on: October 26, 2014, 06:38:34 PM »
Cross sections would also be greater by 4 times and efforts too would be 8 times greater so stresses would also be double, i.e., the big plane is 2 times weaker.


this can get confuseing .

We all know what would happen if these fell off the top of the Empire State Building .







It wasn't Me . Honest .  ;D Anyway , it would depend who landed on top .  ;D

Then theres the matter of SCALE . The Big sucker goes Less Lenghts of itself at the same speed at the same time . So Maybe theres a POINT
at which all the lines overlap / intersect , as to virtuosity in aerobatics  , Particularly seeing someone has to hold the end of the lines / Handle .

Presumeably 60 ft. rad. & 70 ft. rad would not provide the same answer .



LOKOUT BEL  O  O    W >  :P

" The Empire State Building has been named by the American Society of Civil Engineers as one of the Seven Wonders of the Modern World. " PAH ! .



" The famous White Terraces on Lake Rotomahana were unfortunately obliterated in 1886, not by the hand of man but by the forces of nature. “ "
http://tvnz.co.nz/national-news/scientists-claim-pink-terraces-have-been-found-4780158

Online David Hoover

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 290
Re: How Big is too Big?
« Reply #12 on: October 26, 2014, 07:25:43 PM »
Weight correlates with volume so the larger plane would be L^cubed = 8 times heavier than the smaller one.

Only if it's solid construction which our planes are not.  In fact, since strength is a cubed function of section depth and stiffness is a fourth power function the thicker wing will be the stronger and stiffer and will make more efficient use of the material if designed correctly.

I doubt that there's any real technical limit to the size of model we can build but eventually line pull becomes excessive and at some point the plane is just too big to look good flying within the confines of a 70' radius hemisphere.
Life is simple. Eat. Sleep. Fly!
Best, Hoovie

Mike Griffin

  • Guest
  • Trade Count: (0)
Re: How Big is too Big?
« Reply #13 on: October 26, 2014, 08:19:31 PM »
Sometimes I look back in retrospect and think, "why in the hell did I post that ?"

Offline WLGeorge

  • Trade Count: (0)
  • Lieutenant
  • ***
  • Posts: 56
Re: How Big is too Big?
« Reply #14 on: October 26, 2014, 08:57:59 PM »
Mr. Griffin, keep posting these little gems.  I learn something each and every time.  It may or may not be a good thing I learn but by golly I learn.  Actually sometimes I can't even get the drift of what's going on.  Sometimes I think people carry this stuff way to far.  It' gets too deep for a guy that regularly flys in his cow pasture and sometimes lands in stuff that in some ways, reminds me of this place:-).  I enjoy the discussions so keep posting them.

Mike Griffin

  • Guest
  • Trade Count: (0)
Re: How Big is too Big?
« Reply #15 on: October 26, 2014, 11:32:13 PM »
Thank you for making me smile and chuckle Mr. George....I will keep posting...I just get frustrated sometimes when threads get way off subject but that is OK... sometimes you learn something from that too.....for example...I did not know that an Elephant would straddle a car....

Mike

Offline WLGeorge

  • Trade Count: (0)
  • Lieutenant
  • ***
  • Posts: 56
Re: How Big is too Big?
« Reply #16 on: October 27, 2014, 08:37:25 AM »
Yeah, the elephant "bonding" with the car was a bit much but I thought he brought it all together and made his point rather well.  When I throw out my cast net to catch bait I never know exactly what I am going to catch.  Some days it's pogey fish and some days it's eels.  You ain't lived until you have to get eels out of your net.  Kind of like some of these folks:-). Slippery little devils.


Advertise Here
Tags:
 


Advertise Here