Conference vmszoo::rc

    Noise is a legit concern and has cost MANY clubs the use of their
    fields. More and more clubs are adopting noise limits for their
    members. The CMRCM club instituted a 100DB limit this year. I believe
    the Loopers club is also 100DB.
    
    Unfortunately, it's not always the noise LEVEL that is the problem, but
    rather the PERCIEVED noise level. There are many 4 stroke motors that
    are above 100db but they just have a more "acceptable" sound. 2 strokes
    are notorious for having "unacceptable" sound even though they may 
    actually be quieter on a noise meter.
    
    Enya 2 stroke motors are EXTREAMLY loud and come with a flow thru stock
    muffler. OS mufflers come with a baffle installed which helps with the
    noise. 049's without mufflers HAVE to be the most annoying.
    
    I agree manufacture's should be more responsible but until the modeling
    community DEMANDS better mufflers, they won't do anything. If everyone
    went on strike for ONE season and did not buy any new motors and wrote
    letters to the manufacturer's saying "I would have bought a new motor
    this year, but your mufflers are too loud so I didn't", you'd see some
    fast changes.
    
    The makers of effective after market mufflers also need to be more
    responsible by  REASONABLY pricing their product rather than taking
    advantage of engine manufacturers "don't care" attitude and club
    noise limits and price gouging. Davis Deisel makes excellent aftermarket
    mufflers but it'll be a cold day in h*ll before I spend $50 bucks for
    a 40 size muffler. Depending on the motor, that approaches HALF the
    cost of the motor.
    
    The other thing your run into is clubs that have wide open fields with
    nobody near by. Noise just isn't a concern so passing a noise limit
    would be next to impossible. I suspect this is what you were seeing
    although the motors mentioned are notoriously loud.
    
    It "is" a problem and hopefully the engine manufacturers will take the
    hint (and responsibility) and start selling motors with effective
    mufflers. Even if all they did was make an effective muffler OPTIONAL
    at an additional cost.

    Steve,
    
         I agree with most of what you said.  A couple of places where
    I see differences of opinion are:
    
    1)  I think it is a given that non R/C participants will find the
        noise objectionable.  I am going one step further suggesting that
        club members at the field also find excessive noise levels
        unacceptable.
    
    2)  When quieter engines begin selling well, other manufacturers will
        be forced to follow.  In other words, I believe the consumers
        needs ultimately dictate what the manufacturers produce.  Waiting
        for the manufacturers is not expedient to dealing with the noise
        problem.
    
    3)  My club is in the "wide open spaces", but as suggested in the first
        point, I would think the members themselves would enjoy more
        reasonable noise levels.
    
    4)  A $50 muffler that works is a much better value than a $10 muffler
        that doesn't.  If Davis is overcharging I think we just found a 
        potential business where some money can made!
    
    *I read and correspond with a number of Europeans, I think they have
     taken the noise issue a lot more seriously than we have.  It is my
     understanding that they have developed(often home brew) muffler
     systems that work very well. 

One of the problems twith the market is that it is currently price driven. A
cheap muffler is now tossed in the box where none was provided in the 70s. The
noise issues are also a  case where prop selection can really make a difference.
A simple exhause diverter will help with the .40 2 strokes. Again it is a case
where the technology is available but the lazy way is usually taken and doesn't
meet the current standards. The OS baffles make a difference but the cheap
mufflers look the exact same from the outside so the knock-offs don't bother. I
own two Davis mufflers and find that they really help limit the engine noise.
You then have to limit the airframe and prop noise which becomes the major
factor. Not too many first time .40/trainer people will bother going beyond "I
bought a kit and an engine and a radio, teach me to fly"

The $50 Davis solution is better than trying to find a field that still allows
loud engines.

    Re -1
    
    Most of the beginners who join my club come up and hang around the
    field or know someone in the club.  They usually buy for a first
    plane what is recommended by their contact into the club or from
    opinions solicited from hanging around.
    
    I would like to hear this as a possible inquiry to a beginners
    request for what equipment to start with:
    
    "Well we have had good luck with the (insert trainer plane name) and
    the (insert engine name and size).  However, since our club enforces
    a 94 db noise limit, you will also have to buy aftermarket muffler
    (insert manufacturers name) or modify the stock muffler by doing the
    following."
    
    So this may read - "WE like the Great Planes PT40 with an O.S. 40
    2 stroke motor and a Davis muffler to meet our noise code."
    
    If you add up the price tag to get into R/C from scratch the additional
    cost of an aftermarket muffler is not likely to deter any serious
    potential participant.
    
    The problem is the experienced flyers put up with the noise and the
    newcomers follow suite.
    
    Let's change this picture and save our fields, hearing, and sanity!

    I have been on a "less noise kick" at my club for the past three years. 
    I took db measurements of every plane that was flying and published a
    list for all to see.  Then we passed a self-enforced club rule of 97db
    max.  One guy stopped flying his 104db ear-killer rather than modify
    it.  Many experimented with some kind of noise reduction, but the net
    of all the work has been very little long term effect.
    
    I am determined to keep on the trail of noise reduction, but I have to
    admit, after many tests on my own planes with home-made and aftermarket
    mufflers, I have not been very happy with the results.  It just isn't
    that easy to quiet an engine.  True, pay $50 or more and you can do it,
    but some models with tight cowl situations can't use these without
    major surgury to the plane.  Its always a compromise.
    
    And if $50 seems like a lot to pay for a muffler, think of the price of
    a quiet tuned pipe system like the one Dan Weier has on his Stryke. 
    The low level of noise from this setup is incredible, but how many
    people can afford to buy such a setup for every engine they own.
    
    This is not a simple problem.  But it does demand constant attention
    from all of us, and slowly over time we will make it better.
    
    -Joe

    The LLFC has a dual noise limit system. It recognises the lower irritation
    level of a 4-c and limits the 2-c's below 1.20 to 96db and all others
    to 98db, big gas engines included.
    
    Regards,
    
    E.
    
    
    
    
    

    If it were my field, I would strictly enforce a 93dB limit.  I don't
    buy the "mufflers cost too much" arguement but there are not many good
    after-market mufflers out there.  Even the Davis has a VERY POOR
    mounting method using a strap around the engine.  They can come loose
    and if you use a soft mount (also a noise reducer) the muffler will
    surely come loose.  We need good mufflers designed for our individual
    engines.  You can make good ones if you are good at welding aluminum,
    but most of us can't.  My pattern ships are quiet and powerful.  My
    sport planes are loud and wimpy.  
    	There are PLENTY of RC'ers that do not care about noise.  We have
    planes that voilate our 100 dB limit and their owners would fly them
    anyway unless they are told not to.  (they probably fly them when they
    can get away with it)
    	If you go to a Pattern contest, you can hold a normal conversation
    while there are two or three planes in the air at full throttle.  Most
    are in the 90-92 dB range on the ground and this is quiet - especially
    for a 4-stroke.
    
    Charlie
    

    Have come from the land of lost flying sites in 1982 I was stunned by
    the noise levels allowed in the USA. Since then I have campaigned for
    better mufflers and noise limits in every club. With the exception of a
    very few enlightened clubmates I have found abject apathy to the subject. 
    
    Lately things have improved but I am still amazed that people have to
    be told "It's too loud!".
    
    Let me tell you, it gets real quiet once the club loses a site.!
    
    If the manufacturers strapped this problem on it would be so easy for
    them to achieve the noise levels needed. Some British and European
    companies are now doing this but it will take Japan to change before it
    will get better.
     
    E.              
    

    Re: Noise and innovation
    
    I am always amazed by the homebuilt/designed innovations I see at nearly
    all R/C clubs I have visited.  Obviously a lot of thought and effort
    goes into these gadgets.  It's time some of that thought and energy
    went into noise reduction.
    
    There have been so many articles in every magazine about quiet
    muffler designs, it certainly is one of the best covered topics.
    
    I really haven't heard one good excuse yet.  
     

    I have a question that I would like people to seriously answer, as it
    is not being asked rhetorically.
    
    When I was a kid a bunch of us had mini-bikes - you know with 3-5 hp
    horizontal shaft lawnmower engines.  These all came with the standard
    lawnmower muffler.  Soon it became fashionable to remove the muffler
    and just screw in a piece of straight pipe.  These mini-bikes made a
    hell of a lot more noise than before and we thought that they sounded
    cool.
    
    Later on in high school the "motorheads"(guys who spent most of their
    time tinkering with cars and souping them up etc.) always had special
    exhaust systems on their cars which were very loud.  I remember talk
    about how cool these cars sounded among these guys.
    
    Many of the guys who I have met in R/C clubs are very interested and
    knowledgeable about engines, indeed it is the most interesting aspect
    of the hobby for them.  Often they have considerable background in
    car engines, go-karts, motorcycles, etc.
    
    Is it possible that what I and most non R/C'ers consider to be a loud
    and obnoxious sound is actually "music" to the motor lovers ear?  I
    mean the sound of the Grand Prix cars at Watkins Glen is certainly
    earsplitting as are the dragsters at the local strip.
    
    To all engine lovers - Is a loud motor considered cool like on the
    mimi-bikes when we were kids?

>    Is it possible that what I and most non R/C'ers consider to be a loud
>    and obnoxious sound is actually "music" to the motor lovers ear?  I
>    mean the sound of the Grand Prix cars at Watkins Glen is certainly
>    earsplitting as are the dragsters at the local strip.
>    
>    To all engine lovers - Is a loud motor considered cool like on the
>    mimi-bikes when we were kids?

I like my engines loud.
I like to hear it when I fly.

In fact I get real uncomfortable during competition or fun flys when
I am up in the air and there is so much activity around me and/or in
the pits that I can no longer hear my engine.

Cool is not the word I would use.

I also like the 4 strokes puckata puckata puck sound.

I have no desire to exceed any clubs DB limit.

It's too bad neighbors get so upset over noise.
I blame it on the .049's and Enya's more than anything.

I would like to see the AMA lean on the manufactures
and force a reasonable noise lever on all shipped engines.

Kinda like a required gold sticker on transmitters.

I don't want them silent or even as quiet as you see at
the pattern competitions.  I would just like them to come
down to reasonable levels.  Lower for two strokes than four.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Last year at Rhinebeck a guy was flying a precision scale Albatros
    something, you know, the one with the round planked fuse.  It was
    absolutely georgeous and he flew it to perfection.  But the real
    showstopper for me was how quiet it was.  At full power it sounded like
    a powerful electric.  In fact when I saw it fly that's what I thought
    it was.  When I went over to talk to him after a flight, I asked him
    what the engine was.  I think it was a big Supertiger, maybe 2500 or
    3000 (Jeff do you remember?).  That blew me away, because they are
    rather loud engines. 
    
    At any rate, the explanation for the quiet performance was his custom
    muffler and exhaust manifold system.  You'd have to see it to believe
    it.  Dual cannisters one behind the firewall, one further back in the
    fuse.  A pipe coming out of the second cannister then fed a dual
    manifold system exiting out both sides of the fuse just like the full
    scale did.  ABsolutely beautiflu AND functional at the same time.
    Full power had to be about 85 db or less.
    
    Unfortunately, it took him many months of work to get it right and cost
    him a lot of money and time.  There are only a handful of pilots in the
    world capable of doing this kind of work..  
    
    Yes, it can be done, and there are few excuses.  OK everybody, start up
    your welders and build dual cannister muffler systems custom fitted
    with exhause manifolds.  Piece of cake!!
    
    
    -Joe
    

    The main reason that the pattern folks have been able to reduce their 
    noise levels is lower RPM.
    
    The lower the rpm the lower the exhaust and carb note frequency. 
    The lower the prop speed the lower the prop noise.
    
    To still have pulling power at rpms between 8 and 9.5K they went to
    more exotic propsizes such as 12x13 for the 2-c's and 14x14 for 4-c's.
    
    Bigger engines tend to run well at lower rpm anyway so they can be
    silenced heavily with cans etc. and use larger props. Small engines
    usually suffer if over muffled. Irvine engines have designed their
    stroke and porting to be quiet in the first place. The YS and OS61 have
    long stroke set ups that can accept a muffled pipe. The ST2000's plus
    can be heavily muffled. 
    
    The answer is to buy the quiet stuff and force the manufatures of the
    other stuff to follow the quiet path.
    
    
    E.
                                                                         

    As I read the 100dB in one of the previous notes and all that talk of
    possibilities is it is it not! In Switzerland everything is small.
    Exeption the noise-meter. Every club has to own one and aknoledge the
    use of a plane on their field. With an emission of max. 82 dB!!! And
    it's possible. From the smallest plane over helicopters thru to
    impellers. It's all a question of bringing up the will to do it.
    

    Is this 82db at 3 metres?.
    
    E.

    re: 1610.14
    
    
    My friend Robin Lehman's description of power planes in Switzerland
    exactly matches the description in 1610.14.  Each year he goes to
    the IGG aerotow meet and his reports of low noise on the tow planes
    is unbelievable.
    
    These tow planes are typically 90" - 100" wingspan with weight
    in the 20 - 30 lb. range.  They are powered by large gasoline
    engines(G62 and larger).  These planes tow up gliders that weigh
    as much as 50 lbs!
    
    The mufflers are fabricated from butane fuel cans.  Robin claims
    they are inaudible at 200 yds and quieter that his O.S. 300.
    
    Eric mentioned that Irvine has actually made low noise an engineering
    priority.  This is the approach that needs to be taken.
    
    We can achieve reasonable noise level with excellent performance if
    we put our minds to it.  It is already being done in many other
    countries.

    I received the new Model Aviation magazine last night and read a
    pertinent letter to the editor.
    
    Somebody wrote in admonishing Jim Haught for not suggesting electric
    power to potential modelers, siting noise as the primary reason for
    choosing electric.
    
    Jim Haught's reply was something along the lines of "I've been around
    screaming engines all my life, and it just wouldn't seem right not
    to hear that noise."
    
    When the editor of the AMA magazine shows so little concern for noise
    control, I think we see the roots of the apathy surrounding this issue.
    
    The "old-timers" in modeling got started when noise control wasn't
    the issue it is today.  Their failure to change with the times
    exemplified by Jim Haught's remark continues to set a bad precedent
    for the new people coming into the hobby.
    
    Although Kay was the only one who responded to my question about the
    appealing nature of engine noise, I believe that many long time engine
    afficianados have indeed become "desensitized" to the noise, having
    spent so much time around it.  I have experienced this phenomena with
    people who live near airports, railroads, busy roads, etc., after a
    period of time the residents no longer "hear" the sounds like a
    newcomer to the neighborhood would(ie the have become desensitized).
    I truly believe that long time IC modelers no longer have the ability
    to discern what is unacceptably loud.
    

    
      I have been finding I am getting MORE sensitized to the noise the
    longer I fly.
    
      When I first ran the YS.61/pipe in the Stryke it seemed really quiet,
    now that I have grown accustomed to it, it seems loud. People at the
    field are constantly commenting on how quiet it is, but it doesn't seem
    that way to me ( except at idle when it is extremely quiet) until I
    hear someone start up an Enya .45! WOW, it quickly brings reality back
    in regards to how loud these planes can be!
    
      My Shuttle was very quiet with the stock Hirobo muffler, but once
    I switched to a "tuned pipe" type muffler, it got louder. This has 
    constantly been a minor level of annoyance to me, and I am considering
    going back to a stock set up. 
    
      Ironically, the Stryke and Shuttle are probably two of the quietest
    aircraft at our field, but are still too loud as far as I am concerned.
    
      In my opinion, the nicest sounding engine at the field is a .40 
    Surpass a flyer has installed in an Ace 4-40. The low frequency 
    "putt - putt" is like music to my ears. The most obnoxious have to be
    the Enya 2 strokes and the unmuffled .049's. I have always avocated that 
    the noise criteria should take into account BOTH DB level and frequency. It
    sounds like the Lazy Loopers club took both into account, and have
    a nice system.
     
      Until we start getting into the low 80's DB range, I think noise will
    continue to be a problem to our hobby.

           An interesting and timely discussion. Noise levels were brought
up by our club president at the last meeting. There's been some building going
on in the area around our field and the idea is to make sure we're not a problem 
before we get a complaint. 

One of the members who works in a calibration lab is suppose to be taking 
measurements this month and reporting at our meeting Friday night. It should be
a long meeting. The current level that a plane must meet to fly at our field
is 110db  at a standard distance. When asked why we had such a rediculously 
high level one of the members that was on the committee that wrote the rules 
said that at the time it was written smaller engines like the G-38 could barely
meet the AMA suggested level and the large engines were way above. They stuck
the noise level at 110DB so everyone would pass.

    The only real noise the Shuttle makes is a ringing sound!, just like a
    CASH REGISTER....................:-)
    

    
    Eric,
    
       Get with the new technology! Cash registers don't make noise
    anymore, the only sound is the in-line printer printing out a reciept!
    ( I have a stack of receipts several inches high :(
    
       If I have a few more Shuttle crashes, Bob will be able to afford to
    get one of the newer "silent" printers, and totally remove noise from
    the process! :)           

    re. -1 Sounds about right. Nice one 8-).
    
    I can echo what has been said in previous notes in that when I rubber
    mounted my OS91 4-putter everyone commented on how quiet it was, to the
    extent that they were asking was it a 60 sized engine. And now I feel
    it is loud, again I think it is the fact that I have got used to it.
    And again as said before when some of the smaller 2 strokes get going
    the noise is something else. 
    
    I feel that some of the lookalike manufacturers are putting out the
    copies with little regard for the noise and the silencer design. Pity
    cause it will come back and bit them.
    
    I am glad to see a trend in my club towards 4-strokes and rubber
    mounted engines. Silencing comes at a price whether it be rubber
    mounts, or add on silencers, or props in the APC price range.
    
    My 2 cents worth.
    
    Alt-E.

    Since Mr Weier got in before me 8-) my comment below was on my namesake
    across the pond, welll err, big pond. 
    
    >> re. -1 Sounds about right. Nice one 8-).
    
    Eric.

    After banging the "quiet drum" rather loudly, I am researching the
    muffler choices for the large two stroke engines I am considering
    for my glider tug.
    
    It appears that only the O.S. 1.08 comes with a muffler.  The Moki,
    Super Tigre, and Webra engines do not come with muffler and I do
    not know if the manufacturers mufflers are effective.
    
    It appears that most commercial tuned pipes are for .61 size engines.
    
    Where can I find mufflers or pipes for large motors?
    
    Thanks,
    
    Jim 

    Macks Mufflers makes tuned pipes for large engines.
    
    J-Tec makes good quiet mufflers for large 2-strokes.  I have a good one
    of these on my G-38.
    
    Charlie
    

    
    Just thought you might want to know. Someone showed up at our field
    with a beautiful new 1/4 scale cub using a OS 1.08. He had a J-TEC muff
    on it. He has been grounded due to excess noise levels. Our club has a
    90db rule. His engine was so load you couldn't here yourself think.
    Just a thought.
    
    Dennis
    

    
       The Central Mass club is considering getting down to a 90 db limit
    within 2 years. We are currently at 100db ( why even have a limit if
    its this high :), are planning to get to 95 db next year, and 90 the
    year after ( as I understand it ).
    
       My current YS.61 pattern plane ( the one several people have
    commented they can't believe how quiet it is ), is probably running 
    about 90 db. From the sound of some of the engines I have heard, we
    will have our work cut out for us getting everyone to 90 dbs.
                                         
       On the other hand, if we don't succeed, we will probably have our
    work cut out looking for a new field.

    Believe it or not, we have had to tell people not to fly because they
    were over 100 dB.  A stinger with a G-62 was 106.  It's a big problem
    when all of the manufacturers sell engines with very poor mufflers on
    them.  (or none at all)
    
    Charlie
    

  This past weekend my brother and his wife went up to Sabago Maine for rest
and relaxation.  They had the idea of sitting by the lake and maybe taking 
a lazy cruise on the water in a canoe.

  What they got was annoyed!  Apparently there was an r/c float fly-in taking
place.  They said the sound of the planes just about drove them out of their
minds.  They were very thankful that their last day there was windy and 
prevented the planes from flying.

  Now, they know that I'm really into the r/c stuff and are actually quite
fascinated by it.  So they at least have a basic understanding of what's going
on and why.  But it still just about drove them out of their minds!


  Just something to think about.......



             Jim

    Well, they've never witnessed "noisy" planes around you... The L-4 is 
    real quiet!

  That one hurt Jim!  :^)

There is one way to fix this problem...

Finish it and FLY!

(you can always re-kit it later 8^)

  The quicker way would be to SELL IT!!!  :^)

I fear the plane has soaked up too much Balsa-Slo (tm) at your place.