[SPAM] Re: [SPAM] Re: *SPAM* Re: Rules Survey
Bill Southwell
bnbsouthwell at bellsouth.net
Tue Feb 8 19:39:51 AKST 2005
Hi Dave,
You make some really good points ....Thanks! I defiantly agree on
having a wt limit not to have one and you would have a nightmare. I just
went looking at wts of a YS 160 and a Moki 1.8 about 8-9 ozs not as
much as I had thought. Might not be as hard as I thought. The gassers
are were the problem comes in 2-2.5 lbs VS 4 plus....
David Lockhart wrote:
> Bill,
>
> When it comes to this topic, a lot can be learned from the history of
> the event. The limiting can be done with weight, displacement, or
> dimensions. The 5 or 10% of top competitors/designers/innovators have
> always aggressively pushed right to one or more of the limits - and
> the majority of others in the event follow as fast as they can afford
> to - that is the very nature of competition. Without going into a
> comprehensive review of historical rule changes and the effects, I'd
> strongly suggest the best way to limit size/expense is with
> displacement (of course electrics throw a big wrench into that one).
> Simple FACT - Without exception, every single time a limit has been
> removed or raised, the average cost of the plane on the flightline at
> a pattern contest has gone up.
>
> For a long time, the 2x2m limit was meaningless because it wasn't the
> factor that limited the size of the planes. The 2x2m limit has a
> limited impact (and no, that is not a CompArf Impact on a diet) on the
> size of the planes today - most are at 2m length, but few are at 2m
> wingspan. For a long time, the displacement was the only real limit -
> and when that was recklessly thrown away, the planes got bigger (and
> more expensive) in response to the available power. Now the limiting
> factor is weight. Throw that away (or raise it) and the planes will
> get bigger again (and more expensive). How much bigger? Depends on
> how high the weight limit is raised.
>
> At 12 lbs - The guys that don't build light will have the same stuff
> that is marginally over 11 lbs. And some guys will stuff Moki's into
> pattern planes and find out they don't fly really well with heavier
> engines that they were not designed for. And both will be at a
> disadvantage because you will see some HUGE monoplanes with DA50s that
> make the current day stuff look infinitely affordable. Double Vision
> Bipes that are not fragile will be easy to do (an a major PITA to
> transport back and forth to the field, assemble, maintain, etc).
> Fragile bipes bigger than the Double Vision will arrive on the seen.
> Under Chips watchful eye, I put a few minutes on one of the Double
> Vision Bipes a while back - maybe it isn't an advantage in Sportsman,
> Intermediate, Advanced, or even Masters. But in a sequence full of
> rolling circles, rolling loops, and integrated loop/roll segments, it
> is an advantage (as long as the horsepower is available, which it
> would be if the weight limit went up). And what wins the top class,
> is what the majority will shift to. The reason the Double Vision has
> not caught on more in pattern yet, is because the plane is fragile at
> 11 lbs, and it does require a strong powerplant to adequately power
> the plane (especially at 94 db).
>
> If no weight limit - How about a 30% Ultimate style Bipe - give or
> take 70" span, 78" long, 1700 squ, and maybe 20 lbs??? Anyone who
> doesn't have a deeper checkbook, full sized stretch van or model model
> trailer, and model trailer will be at a disadvantage. Check some IMAC
> kits - the numbers jive. Minimally you will be adding 4 more servos
> (to maintain pattern standards of servo power to surface), and a
> monster cost increase in engine, muffler, softmount, prop, spinner for
> your DA50 or GT80 twin. Increased cost of the kit, building,
> transporting, setup, and maintenance should be obvious enough.
>
> Something that I think that has been overlooked in this thread is the
> "fourth" limiting factor in our event - noise - 96 db for AMA, 94 db
> for FAI. In my opinion, 94 db is the real number because any
> manufacturer who wants to sell to the pattern market is going to want
> to be able to market/target FAI. Displacement unchecked equals more
> noise. Heavier planes require more power which equals more noise.
> Unless of course additional money is spent on exhaust systems to keep
> things quiet. And more and more the prop noise is diminished by going
> to 3 or 4 blade props (quieter, but less efficient, so now more power
> is needed again). Very few large displacement sport engines (gas or
> glow) are equal to or quieter than a pattern setup (and most YS DZs
> running in their power band are also above 94 db) because of the
> larger displacement and larger diameter prop (increased tip speed).
> Add up the costs for the quality exhaust systems, softmounts, and
> props to keep the DA50 quiet and I think you'll find a 140RX to be
> quite cheap.
>
> Regards,
>
> Dave Lockhart
> DaveL322 at comcast.net <mailto:DaveL322 at comcast.net>
>
>
> ----- Original Message -----
> From: "Bill Southwell" <bnbsouthwell at bellsouth.net
> <mailto:bnbsouthwell at bellsouth.net>>
> To: <discussion at nsrca.org <mailto:discussion at nsrca.org>>
> Sent: Tuesday, February 08, 2005 11:47 PM
> Subject: [SPAM] Re: *SPAM* Re: Rules Survey
>
> >
> >
> > Hi Dave,
> >
> > How do you mean bigger plane? Are you refering to a little more sq
> > in? Didn't the older designs during the fourstroke 120-140 change adapt
> > too the power and wt with a bigger wing? We can't go any bigger if the
> > 2M requirment is in play. I am not trying to be difficult but the wt
> > problem at least in my mind ( what a crazy place that is!) is that the
> > power plants are doing all they can do due to the airframe size. The
> > larger slower turning engines might cause some evolutionary changes
> > but not a huge change in airframe layout. The airframes are
> optimized
> > for the 2M size the engines are tapped out. No beef to them! If the
> > power becomes easy to manage $$$ and more reliable to the average guy
> > then we have more interest and a lot more fun flying. Another
> thought
> > ...My Moki' 1.80 on a 20" prop were pretty quiet with very little in
> the
> > way of a muffler. The bigger disk made a great brake on down lines and
> > landings and the engine ran like a sewing machine. Change is good!
> >
> >
> > David Lockhart wrote:
> >
> > >Bill,
> > >
> > >The current set of rules basically establish a performance level
> that is a
> > >target to shoot for. I believe you are correct in that the current
> > >performance level might be easier to approach if a 12 pound plane were
> > >allowed. BUT - if the 12 pound plane is allowed, the performance
> level will
> > >increase and you will be in the same situation then as you are now,
> but we
> > >all will be paying for the added expense of the bigger plane - and the
> > >planes will get bigger if the weight limit is increased - bigger
> planes do
> > >fly better and competitors will seek that advantage.
> > >
> > >Regards,
> > >
> > >Dave Lockhart
> > >DaveL322 at comcast.net
> > >
> > >----- Original Message -----
> > >From: "Bill Southwell" <bnbsouthwell at bellsouth.net
> <mailto:bnbsouthwell at bellsouth.net>>
> > >To: <discussion at nsrca.org <mailto:discussion at nsrca.org>>
> > >Sent: Tuesday, February 08, 2005 9:56 PM
> > >Subject: Re: *SPAM* Re: Rules Survey
> > >
> > >
> > >
> > >
> > >>Tom how so? If there are available engines that actually hold up but
> > >>are a bit more porky....but also a lot cheaper to own both in intial
> > >>purchase and in up keep how can it lead to a more expensive airplane.
> > >>Cost of the present designs are due to the materials and mathods of
> > >>production required tokeep the weight down. A little more room would
> > >>make more pedestrian material like balsa , ply. and foam to come
> back or
> > >>at least make the average builder have hope.
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>Tom Shaw wrote:
> > >>
> > >>
> > >>
> > >>>You guys need to leave well enough alone. With the unlimited engines
> > >>>a higher weight limit is just going to ecourage larger more
> expenseive
> > >>>airplanes. That will amount to fewer flyers.
> > >>>
> > >>> ----- Original Message -----
> > >>> *From:* Gray E Fowler <mailto:gfowler at raytheon.com>
> > >>> *To:* discussion at nsrca.org <mailto:discussion at nsrca.org>
> <mailto:discussion at nsrca.org>
> > >>> *Sent:* Tuesday, February 08, 2005 4:25 PM
> > >>> *Subject:* RE: *SPAM* Re: Rules Survey
> > >>>
> > >>>
> > >>> Here comes the dreaded weight debate again....
> > >>>
> > >>> Consider this-Anyone in the upper level classes would not be too
> > >>> smart to have a plane heavier than it needs to be. But, lets
> > >>> pretend there is a hot new Sportsman named uh lets see.....
> Chuck.
> > >>> Chuck tears up 401 after 3 contests, and he is flying his best
> > >>> airplane that most FAI guys would consider a toy (and I do not
> > >>> mean the "foamie toys" pictured in last months Model Aviation
> > >>> being held by a guy named "Chuck") and so moving up to
> > >>> Intermediate halfway thru his first season, last 3 contests were
> > >>> quite a challenge, BUT he places in 402 anyway!
> > >>> In the off season, he saves his pennies, keeps his wife happy and
> > >>> gets a used REAL pattern plane, built by someone who has a slight
> > >>> heavy hand, and alas it weighs 11.5 lbs. Now this here Chuck is
> > >>> good and pumped up and I would place money that this theoretical
> > >>> person could place at the NATS, but his plane is over weight!!!!!
> > >>> one more !
> > >>>
> > >>> Sorry Chuck, even though you are flying at a disadvantage, we
> will
> > >>> not let you play at the NATS........Oh unless you can spend $2k
> > >>> more on another plane.
> > >>>
> > >>> The story you have just read is about to be true, once we do not
> > >>> let Chuck fly at this years NATS. But at least the French FAI
> rule
> > >>> makers are happy.
> > >>>
> > >>> Consider a weight change. It does not need to be across the board
> > >>> and for the life of me I cannot imagine why it needs to align
> with
> > >>> FAI. Chuck will have a 5Kg plane *BY THE TIME HE REACHES
> FAI-*and
> > >>> the French can be happy then*.*
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>
> > >>>
> > >>=================================================
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> > >>
> > >>
> > >>
> > >
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