[NSRCA-discussion] Long - RE: Weight

[Matthew Frederick]

Excellent post. I couldn't have said it better.

Sent from my iPhone

On Jun 4, 2009, at 11:17 AM, "Dave" <DaveL322 at comcast.net> wrote:

> Honestly, I understand (and agree) with the intention to allow the  
> "cheap
> electric", but it is no different than trying to tweak the rules for  
> the
> "cheap gas engine" and won't (my opinion, with substantial history  
> to back
> it) work-
> - why should the rules be tweaked to essentially allow someone the  
> latest
> greatest (electric) without paying for it (either with time, or $$$,  
> or
> experience)?  The latest greatest always cost more - that is the  
> nature of
> competition.
> - I truly believe the time spent researching, designing, crafting,
> submitting, and implementing such a proposal will largely be wasted  
> because
> the process is relatively slow and can not possibly keep up with the  
> rate of
> change in electrics as technology advances.
> - Anyone who wants to try electric - go right ahead - and fly a  
> current day
> design at a slight weight disadvantage at local comps (most guys  
> don't go to
> the NATs anyway) - no one is going to ask or care about a couple  
> ounces over
> 11 lbs.  And if they do decide to go to the NATs, they can suck it  
> up and
> buy 1 expensive pack for official flights and the scale.
>
> With the understanding of the intent to allow cheap electrics, the
> unintended consequences of any rule change needs to be carefully  
> evaluated
> prior to submitting a proposal.  In this case, the unintended  
> consequence
> will be the opportunity for the TOP LEVEL electric designs to grow
> substantially in size and weight, which will drive the cost up for all
> competitors (glow and electric) to compete with the new performance
> standard.  The average plane is influenced by whatever the TOP LEVEL  
> stuff
> is - that is why both electric and glow TOP LEVEL stuff has always  
> been
> right on the limit of whatever the rules are at the time, and that  
> is the
> way it will always be - again, it is the nature of competition.
>
> The top level electrics right now weigh well under 11 lbs......10  
> lbs is
> quite possible with electric monoplanes, which is why some are able  
> to sneak
> biplanes in under 11 lbs - of course this is by shaving every ounce  
> off the
> airframe (reducing it's lifespan and making it relatively fragile) and
> pushing the lipos harder (also reducing it's lifespan).  So when you  
> look at
> 8.7 lbs considering the weight of the electrics that are marginally
> overweight (with the Zippy packs and AXI), the unintended  
> consequence is the
> guys that have 7.5 lb airframes now have 1.2 lbs of additional  
> weight to add
> to make the plane bigger - and you know it will be used, and  
> probably along
> the lines of -
> - 6-8 oz for structure
> - 3-4 oz for more motor (more power)
> - 4-5 oz for more lipo (which would still be rated the same 5300  
> mah, but be
> heavier to allow more voltage under load, thus delivering more watts  
> through
> the course of the flight - and it will be called a "High Power  
> Prolite", or
> "High Power AEON", whatever.)
> - 1-2 oz more for bigger servos and more RX battery
>
> And 2 years after the 8.7 lb rule is introduced, there will be a  
> cheap copy
> of the "High Power Prolite" will be available and it will weigh 5 oz  
> more,
> and the desire will be to raise the 8.7 lbs to 9.2 lbs.
>
> Allow 5.5 kg (12 lb) or 6 kg (14.3 kg) airframes, and yes, you will  
> have
> DA50 powered stuff that is competitive with current day designs, but  
> it will
> not be competitive with the YS built for 6 kg airframes for the same  
> reason
> gas is not competitive with glow now.
>
> Allow 5.5 kg weight limit, and you instantly solve the problem of  
> all the
> guys that are a couple oz over the current 5 kg weight limit.  And  
> the new
> designs will grow, and in 1-2 years, the new designs will be showing  
> up a
> couple oz over the 5.5 kg limit.
>
> It may be true that for the TOP LEVELs of competition that any  
> airframe is
> obsolete in 3 years......BUT.......changing the rules to allow 15 lbs
> airframes will obsolete (immediately) not only the airframes, but the
> powerplants and servos.....and up the horsepower requirements  
> substantially
> which will increase the noise (only measured at the NATs) and require
> substantially more cost to reduce the noise (to achieve 94/96 db at  
> the
> NATs).
>
> All of the above is escalation no different than what we've seen in  
> the past
> -
> - "we" started with .61 cubic inch (10 CC) limit and 5 kg......the  
> only
> practical limit was the displacement.
> - "we" allowed 120 4C (big mistake, short sighted, or should have been
> continually adjusted as competition 4Cs developed).  Airframes grew  
> and cost
> went up....some airplanes actually exceeded 2M (which was not yet a  
> limit).
> - "we" allowed unlimited engines to, in part, cover up the mistake  
> of the
> 120 4C, and, in part, to allow cheap gas engines (another big  
> mistake, again
> short sighted).  The 2M rule went into place because that was  
> essentially
> the "largest" plane in existence at the time.  The airframes got  
> bigger
> again (fuse volume), and cost went up again, and the practical limit  
> to
> airframe size became the 5 kg weight limit.
>
> Of course we also have the noise limit - that is really a separate  
> issue -
> but - it is worth noting that larger airplanes require more power,  
> and more
> power is more noise (or more expense to keep the noise from  
> increasing).
>
> "Wouldn't it be nice if"........is a dangerous lead in to rule  
> changes with
> unintended consequences.  The gas engine, the heavier lipo, the  
> heavier
> motor, the heavier airframe, etc.....will all forever be less  
> competitive
> because the limits will always be pushed by the airframe/powerplant  
> that has
> the best power to weight ratio, and that will always cost more, and  
> always
> be more sensitive to weight conscious building techniques.  No  
> change in the
> rules will ever allow parity for equipment that does not have the  
> best power
> to weight ratio.
>
> Someone else made the point that they perceived the less the rules  
> change,
> the more available airframes and equipment are (2nd hand) - I  
> couldn't agree
> more.  Stop changing the rules to allow (intended or not) higher  
> performance
> airframes, and the "old" ones won't be obsolete so quickly.
>
> Personally, after a lot of research and planning, I switched to  
> electric in
> 2006....and the expense was big.....especially because I had  
> perfectly good
> glow stuff, and maintained glow and electric for about 1 year.  To  
> date,
> I've built 3 electric airframes (1 Abbra, 2 Prestige), and between  
> them I
> have run 12 different motors of different brands, weights, in/out  
> runners,
> and just about every mounting configuration you can think of.  The  
> majority
> of the motors have been < $300, and I've always used the Castle 85HV  
> (which
> I think has always been and still is the least expensive ESC  
> available for
> the job).  My planes have weighed anywhere between 9 lbs 13 oz and  
> 10 lbs 14
> depending on the configuration.  If I had the time, $$$, resources,  
> etc, I'd
> design and build my own stuff right up to the limit, whatever that  
> limit
> might be.  As I do have limits (as most of us do), I'll get as close  
> to what
> I think optimum performance is, and it may or may not be pushing the  
> limits
> (for whatever reasons).
>
> In the past 3 years, I've spent a huge amount of time on email, phone,
> forums, in my shop, in others shops, etc....working with people on  
> how to
> assemble electric pattern stuff....and most are not using the most  
> expensive
> airframes or equipment, and all are under 11 lbs.  Bottom line is  
> that you
> can not take the largest, cheapest, and heaviest of each respective
> component and have a sub 11 lb electric OR glow plane.  Nor do you  
> need to
> have the most expensive and lightest example of each component to be
> competitive.  You do need to research, plan, and make educated  
> decisions.
> No offense to anyone with an 10 lb 18 oz plane....they do  
> exist....and most
> are being happily flown, and most can make weight for the NATs if  
> the time
> is spent in advanced.
>
> Regards,
>
> Dave
>
>
>
>
>
>
> -----Original Message-----
> From: nsrca-discussion-bounces at lists.nsrca.org
> [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of
> verne at twmi.rr.com
> Sent: Wednesday, June 03, 2009 1:53 PM
> To: General pattern discussion
> Subject: Re: [NSRCA-discussion] Weight
>
> Derek,
> We've discussed raising the weight before and it's always been voted  
> down. I
> believe for good reason. Dave Lockhart has steadfastly argued that  
> raising
> the weight limit will inevitably increase the size of our planes,  
> obsoleting
> anything that preceded it. I agree with him.
>
> What I'm trying to do is make it more feasible for someone wanting  
> to try
> electric to be able to do so without having to buy the most expensive
> equipment available. For example, at a contest last weekend, a  
> friend and
> fellow pattern pilot had a set of Zippy packs that weighed roughly 5.5
> ounces more than my FlightPower packs. Pretty much the same  
> difference when
> compared to Andrew's TP packs. The Zippy's as we all know, were less  
> than
> half the cost. I know for sure that my friend would have made weight  
> with my
> FP's or Andrew's TP's, but he couldn't afford that after all the other
> "electric" purchases.
>
> What I'm going to propose once I have it all worked out, is that  
> electric
> airplanes weigh LESS than glow planes and be weighed without their  
> "fuel",
> just like glow. The Rx battery will have to be in the plane, just  
> like glow.
> Yes, I realize that there are UBEC's out there but I don't know of  
> anyone
> who trusts them with the kind of current we're running. In any  
> event, my
> preliminary research indicates that roughly 8.7 pounds should be  
> just about
> right, but I want to make sure before I submit the proposal.
>
> Verne
>
>
> ---- Derek Koopowitz <derekkoopowitz at gmail.com> wrote:
>> Verne,
>>
>> When I was at the CIAM meeting in March one of the proposals which  
>> was
>> passed by the helicopter guys (F3C) was to modify the weight limit  
>> for
> their
>> helicopters effective 1/1/2010.  Here is the new wording:
>>
>> a) WEIGHT: The weight of the model aircraft (*with *fuel *or  
>> *batteries)
>> must not exceed *6.5 *kg.
>>
>> Unanimously approved by the Plenary Meeting. Effective 01/01/10.
>>
>> I'm going to feel out the rest of the F3A sub-committee members to  
>> see if
>> there is interest in raising the F3A weight limit to 5.5kg.  What  
>> does
>> everyone think about this?
>>
>> -Derek
>> On Wed, Jun 3, 2009 at 7:51 AM, <verne at twmi.rr.com> wrote:
>>
>>> Bill,
>>> I've been working up an AMA rules proposal to address that very  
>>> issue.
>>> Unfortunately, it won't be up for vote by the contest board anytime
> soon. In
>>> the meantime, there's one area you didn't mention in the glow to
> electric
>>> comparison and that's that an electric plane doesn't need as much
> internal
>>> reinforcement because there's virtually no vibrational effects to
> contend
>>> with that you do with glow. That equates to lighter airframes being
>>> acceptable as well as small, light, lipo packs to power the Rx and
> servos.
>>> An 8 minute e-flight typically uses about 50 mah. The same flight in
> glow is
>>> typically 200+ mah. All that aside, most electric pilots will tell  
>>> you
> that
>>> making weight in electric is generally a pretty expensive  
>>> proposition
> with a
>>> limited number of 2 meter planes available that are usually
> vacuum-bagged
>>> composite affairs. In addition, your best chances for making  
>>> weight will
>>> also necessitate the lightest and generally most expensive motors  
>>> and
>>> batteries. There are exceptio
>>> ns, and I'm sure we're about to hear about most of them, but I'll be
> able
>>> to point to just as many examples of guys that fly overweight at  
>>> local
>>> contests where they know they won't be weighed and the only thing
> they're
>>> really guilty of is not spending the extra money that the lightest
> batteries
>>> and motors cost. In every other way, the planes they're flying are  
>>> the
> same
>>> as the ones they're competing against. The proposal I'm working on  
>>> is
> not
>>> self-serving because my planes make weight, but getting there is  
>>> both
> too
>>> expensive and unreasonable, in my opinion. My proposal won't be to  
>>> allow
>>> electric planes to weigh more, it'll require that they weigh less,  
>>> but
>>> without the "fuel". The proposal will take into account that  
>>> electric
> motors
>>> are inherently lighter than their glow counterparts as well as the
> reduced
>>> structural requirements. It will limit the mah of permissible  
>>> packs to
>>> control that end of the equation and there's already a voltage  
>>> limit on
> the
>>> books which is fine as it
>>> stands. I'm currently doing survey work at the contests I go to to  
>>> see
>>> where everybody is at weight-wise and will post my proposal on  
>>> this list
>>> soon. After that, it's up to all concerned to voice their opinions  
>>> to
> their
>>> respective Contest Board reps.
>>>
>>> Verne Koester
>>> AMA District 7
>>> Contest Board
>>> ---- Bill's Email <wemodels at cox.net> wrote:
>>>> I am certain this has been beaten to death while I was off doing
> other
>>>> things, but can anyone explain this:
>>>>
>>>>
>>>> Rule 4.3: Weight and Size. No model may weigh more than five (5)
>>>> kilograms (11 pounds) gross, but excluding fuel, ready for takeoff.
>>>> Electric models are weighed with batteries.
>>>>
>>>> Why can't an electric "deduct" the equivalent of 16 ounces of  
>>>> fuel??
> Is
>>>> a plane without fuel rally "ready for takeoff"??
>>>>
>>>> I know it is likely a direct copy of the FAI rule, but it makes no
>>>> logical sense. IC powered planes are weighed without fuel and can
> weigh
>>>> right at 11 pounds. Add fuel and it could add another 10 to 12  
>>>> ounces
> of
>>>> weight. That's OK. But if an electric with batteries weight
>>>> 11.0000000000000001 pounds it is overweight by the rules.
>>>>
>>>> Put another way, what does a YS and full fuel weigh compared to a
>>>> motor+ESC+batteries?
>>>>
>>>> Hacker C50 14XL = 18.2 ounces
>>>> Hacker Spin 99 ESC = 3.7 ounces
>>>> 10S packs = +/- 43 to 46 ounces
>>>>
>>>> Weight w/o batteries = 21.9
>>>> AUW w/batteries = 66.9 ounces
>>>>
>>>> YS 1.70 = 33.6 ounces (955 grams)
>>>> AUW with tank and fuel = 45 ounces +/-
>>>>
>>>> So I can see an argument that the electrics have a weight advantage
>>>> when it comes to just the motor and ESC. But with "fuel" electric  
>>>> is
> at
>>>> a 20 ounce disadvantage.
>>>>
>>>> So if I build a plane for electric I need to build it 20 plus  
>>>> ounces
>>>> lighter than if I was going to put a nitro motor in it. How does  
>>>> that
>>>> make sense. I know I am missing something important here, so  
>>>> educate
> me.
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> NSRCA-discussion mailing list
>>>> NSRCA-discussion at lists.nsrca.org
>>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>> _______________________________________________
>>> NSRCA-discussion mailing list
>>> NSRCA-discussion at lists.nsrca.org
>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>>
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion