[NSRCA-discussion] Weight

Wed Jun 3 12:05:40 AKDT 2009

 I think Verne is right on this. We need some form of fairness here and the current system is not fair or logical. Mike

--- On Wed, 6/3/09, verne at twmi.rr.com <verne at twmi.rr.com> wrote:

> From: verne at twmi.rr.com <verne at twmi.rr.com>
> Subject: Re: [NSRCA-discussion] Weight
> To: "General pattern discussion" <nsrca-discussion at lists.nsrca.org>
> Date: Wednesday, June 3, 2009, 12:53 PM
> 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.
> > > >
> > > >
> > > >
> > > >
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