[NSRCA-discussion] Fwd: Electric Weight Proposal Logic andRationale

[Ron Van Putte]

On Jun 21, 2007, at 6:11 PM, Ed Miller wrote:

> Ron V P, before this "proposal" is submitted, please let John F  
> know that
> there are 16 ounces in a pound, at least in the rest of the USA.  I  
> think a
> lot of pattern competitors would  be very pleased to see their  
> planes weigh
> 10lbs 11ounces or even 10lbs 11.9 ounces.  The ones weighing 10lbs  
> 15.9
> ounces or 4999 grams are the guys sweating....

I'm not sure what was meant by the above, but 20 ounces of FUEL  
(which is a volumetric measure) actually weighs about 16 ounces,  
since fuel's specific gravity is about 0.8.

> Any reason why John F isn't on this list ??

Yes.

Ron Van Putte

> ----- Original Message -----
> From: "Ron Van Putte" <vanputte at cox.net>
> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
> Sent: Thursday, June 21, 2007 2:56 PM
> Subject: Re: [NSRCA-discussion] Fwd: Electric Weight Proposal Logic
> andRationale
>
>
> I agree with much of what Mark says, BUT.  The reason we are now
> stuck with electric-powered airplanes being required to be weighed
> with batteries and glow-powered airplanes allowed to be weighed
> without fuel is that what's in the FAI/F3A rules and it was
> arbitrarily extended to apply to AMA rules by an AMA official (I
> think it was Steve Kaluf), without an official rule change being made.
>
> Ron Van Putte
>
>
> On Jun 21, 2007, at 1:37 PM, Mark Atwood wrote:
>
>> Go Gavey, Go Davey, Go Davey...
>>
>> In my opinion,  ANY change in the rules will be exploited.  And why
>> does there need to be equity or parity of equipment???  In ANY
>> competitive sport there are limits that effectively define what is
>> and is not competitive.  Should wood propellers have a special rule
>> to help them be more competitive?  They’re cheaper!  That’ll help
>> get more people into pattern if we give a scoring bonus to people
>> using wooden propellers.   Sorry, that’s being a little obnoxious,
>> but that’s the way this feels.  I’d love to use cheaper, lighter
>> paints...but the burden of nitro is making things fuel proof.
>> Everything I use on a plane is decided based on what will be either
>> cool, competitive, or cost effective.  It’s rare that I get to have
>> all three.  Where’s the proposal to increase the weight for Gas
>> engines since none of the current designs are competitive at the
>> current weight?  Talk about saving some money in pattern...whew...
>> $3/gal vs $20/gal times 50 gal a season....
>>
>> I think the biggest point that Dave makes is that E power is still
>> SO new that setting rules now will be moot in a year.  By the time
>> they’re voted in, they’ll need to be changed.
>>
>> We didn’t have electrics in pattern for MANY years because it
>> wasn’t competitive (Ask Dave Von Linsowe who tried it numerous
>> times). Not enough power for the weight.  No one argued for Parity
>> rules.  The only reason there’s an issue now is because they’re
>> getting close to parity on their own.  My guess is they’ll get
>> there on their own too.
>>
>> -M
>>
>>
>> On 6/21/07 1:09 PM, "Davel322 at comcast.net" <Davel322 at comcast.net>
>> wrote:
>>
>>> Not a good proposal.
>>>
>>> The fatal flaw is this - Glow planes receive no benefit from
>>> carrying additional weight.  Adding weight to glow reduces the
>>> power to weight ratio, carrying un-needed fuel detracts from
>>> performance.  Adding more battery weight to an electric could
>>> substantially increase the power output AND power to weight ratio.
>>>
>>> Additionally, the proposal fails to acknowledge the inherent
>>> benefits of electrics over glow (reduced structure is possible
>>> with reduced vibration, reduced finish is possible with lack of
>>> oil...and many more).
>>>
>>> An additional flaw (conceptually) is that this idea is very
>>> shortsighted.  Electrics are still in their infancy.  The motors,
>>> batteries, and ESCs will all get lighter and more efficient (and
>>> cheaper) with future develepment.  Airframes tailored for electric
>>> will continue to improve further reducing weight.  Within the
>>> existing rules structure, a very solid arguement could be made
>>> that electrics can already achieve equal performance to glow, and
>>> a very solid arguement could also be made that a cutting edge
>>> electric has better performance than a cutting edge glow.
>>> Electrics do not need any additional advantages at this time and
>>> will be dominant in the near future within the existing rules
>>> structure.
>>>
>>> An average flying weight for glow of 11.5 lbs assumes the average
>>> dry weight is 11 lbs.  11 lbs is not the average dry weight.
>>>
>>> The assumption that 20 fluid oz is the average tank size needed
>>> for completion of a pattern flight assumes a Masters or FAI
>>> preliminary flight.  Not all flights are for Masters and FAI.
>>> Substantially less fuel is needed for Adv, Int, and Sportsman.
>>> Further, the assumption would also seem to be based on a glow
>>> engine with a very high fuel consumption ratio.  Plenty of 2C
>>> setups complete Masters and FAI on 12 oz.....well managed 4Cs do
>>> almost as well.  Perhaps 14 fluid oz would be a better average
>>> (~11 oz actual weight).
>>>
>>> The past few years, I've been fortunate to be flying some very
>>> high quality composite models (glow Vivats and electric
>>> Prestiges).  The Vivats were 9 lbs 14 oz + 12 oz of fuel (more
>>> than enough for the Webra 160MC to get through 1.5 PO7s) for an
>>> average flight weight of 10 lbs 4 oz.  My electric Prestige with
>>> TP5300s was 10 lbs even on the 2006 NATs scale.....current
>>> configuration puts it at 10 lbs 3 oz.  At ~$1900 USD per copy, the
>>> Vivat and Prestige are not cheap, but hardly the most expensive
>>> option.  On the lower end of the price scale, there are plenty of
>>> options from UltraRC, Fliton, etc, that can be well under weight
>>> electric or glow.  The Black Magic series is among the biggest
>>> planes currently and recently available and can be built at 10 lbs
>>> electric and well under 10 lbs glow.
>>>
>>> Applicable to this proposal (and others past, current, future) is
>>> that the proposal should be evaluated from the perspective of a
>>> competitor looking for a competitive advantage - ie, not how the
>>> proposal will effect current equipment/desigsn, but what higher
>>> levels of performance could potentially be achieved by a
>>> competitor looking to exploit the new rules.  Historically, any
>>> increase in size, weight, or displacement has resulted in larger
>>> and more expensive airframes.
>>>
>>> Regards,
>>>
>>> Dave Lockhart
>>> DaveL322 at comcast.net
>>>
>>>
>>>> -------------- Original message --------------
>>>> From: Ron Van Putte <vanputte at cox.net>
>>>> I got the following from John Fuqua. He is going to submit a
>>>> proposal to increase the weight limit for electric-powered
>>>> airplanes to 11.5 lbs. I suggested to him that he "float" his
>>>> rationale by the NSRCA Discussion List, to get some feedback.
>>>> Here is his response.
>>>>
>>>> Ron Van Putte
>>>>
>>>> Begin forwarded message:
>>>>
>>>>> Date: June 21, 2007 10:40:36 AM CDT
>>>>> To: "Ron Van Putte" <vanputte at cox.net>
>>>>> Subject: Electric Weight Proposal Logic and Rationale
>>>>>
>>>>>
>>>>> Now that I am flying electrics I have come to realize the
>>>>> penalty that electric planes have when being built that gas
>>>>> planes to not have. That building penalty is significant under
>>>>> the current rules. Electrics must be built lighter, to include
>>>>> paranoid attention to everything used - wood, paint, fittings,
>>>>> etc., - all to make weight. Much more of a concern than gas
>>>>> planes. Also I remember many instances at the NATs when we were
>>>>> weighing airplanes, when the contestant was doing all he could
>>>>> do to meet weight with a gas plane to include cleaning the fuel
>>>>> residue inside and out. A lot of gas planes were weighing in at
>>>>> 10lb 11oz, 10lb 11.9 oz, even one that was only a few grams
>>>>> under 5 kilos. Then they get to add a minimum of 16 to 20 ozs of
>>>>> weight by fueling up (and there is no limit to fuel capacity).
>>>>> Takeoff weights are 12 lbs or more. This situation seems bizarre
>>>>> and illogical when you put some thought into it. Electrics have
>>>>> a finite weight and gas planes are open ended at Takeoff. Even
>>>>> though the 2005 NSRCA survey did not support an electric weight
>>>>> increase it occurred to me that the survey did not offer any
>>>>> logic or rationale as to why some increase would be justified or
>>>>> not. I have attempted below to come up with a reasonable
>>>>> compromise on electric weight allowance. I believe the rationale
>>>>> supports an increase but it would be nice to have NSRCA
>>>>> membership look at it to find the fatal flaw in the rationale
>>>>> before it gets submitted. The two paras below are taken from the
>>>>> proposed change. Lets put it out and see what the discussion
>>>>> list comes up with.
>>>>>
>>>>> John
>>>>>
>>>>> Change paragraph 4.3 Weight and Size page RCA-2 to read: No
>>>>> model may weigh more than 5 kilograms (11 pounds) gross, but
>>>>> excluding fuel, ready for takeoff. Electric models are weighed
>>>>> with batteries and are allowed an additional 8 ounces for a
>>>>> total of 11.5 pounds ready for takeoff. No model may have a
>>>>> wingspan or total length longer than two (2) meters (78.74  
>>>>> inches).
>>>>>
>>>>>
>>>>> Logic behind proposed change, including alleged shortcomings of
>>>>> the present rules. State intent for future reference.
>>>>>
>>>>> Today‚s 2 meter RC Aerobatics fuel powered aircraft typically
>>>>> use fuel tanks with a 20 fluid ounce capacity. A 20 fluid ounce
>>>>> Crank Tank containing 25% Cool Power Pro Pattern fuel was
>>>>> tested. The fuel weighed 17.3 ounces. Allowing for variation in
>>>>> tank sizes and fuel type a conservative weight of 16 ounces of
>>>>> fuel on average seems appropriate. This means that an allowable
>>>>> takeoff weight for fuel powered aircraft is at least 12 pounds.
>>>>> Assuming that all fuel is consumed during the flight, the
>>>>> average weight for the aircraft is 11.5 pounds. By restricting
>>>>> electric powered aircraft to the takeoff weight of unfueled
>>>>> aircraft an unfair weight penalty is being arbitrarily imposed
>>>>> against the electric model. By allowing electric aircraft an
>>>>> AVERAGE flying weight of the fuel powered aircraft, flying
>>>>> weight equity is restored.
>>>>
>>>
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>>
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