[NSRCA-discussion] Airplane Weight

[Ed Alt]

John


The overall volume of today's 2M Pattern ships is much larger than what you were building, so there's plenty of  area to accumulate weight with just minor process variations when parts are laid up and when they're painted.  And then there's the *very* outdated method for mounting the main LG that still persists in nearly every airplane offering.  From what I have heard, expect to see a major improvement to the old ways in the latest CK Aero designs.  Remember how Wistmodel did the LG system on the Bravo?   If you don't remember the Bravo, it's an improvement over what Wistmodel did for the Prestige and Vivat. There's a big weight savings with a significant increase in structural integrity with that method with that method.  It transforms the fuselage skin in the area of the LG mount into a very strong stress distribution system.


BTW, did you guys ever figure out what was causing the gravitational anomolies up there in CT?  lol


Ed


________________________________
From: NSRCA-discussion <nsrca-discussion-bounces at lists.nsrca.org> on behalf of John Pavlick via NSRCA-discussion <nsrca-discussion at lists.nsrca.org>
Sent: Sunday, February 12, 2017 3:33 PM
To: 'General pattern discussion'
Subject: Re: [NSRCA-discussion] Airplane Weight

You guys crack me up with all of this weight stuff. The first 2-meter airplane that I EVER built was one of Mike Hester's original (hand-cut by Melissa) Black Magics. With an OS 160 it weighed 10 lbs 8 0z. Now I know it wasn't electric so there were no batteries in it but come on guys. This was my first big 2-meter airplane and it wasn't a $3000 ARF. I built this out of balsa-wood, foam and tissue paper (I used silkspan and nitrate dope instead of F.G. on the fuse) in my basement. With CA, Epoxy and Elmer's Carpenter's glue. I haven’t built one of these as an electric yet but I'm sure I can get it to come out within the 5kG limit with suitable batteries.

Most of you guys aren’t even building airplanes anymore. You're just putting them together. I'm sure you pay dearly for all of the pieces because they're "ultra-light-weight Pattern components". Why are people still having so much trouble with weight?

John Pavlick
Cell: 203-417-4971
Integrated Development Services


-----Original Message-----
From: NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Ronald Van Putte via NSRCA-discussion
Sent: Saturday, January 28, 2017 2:00 PM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] Airplane Weight

The problem is that you need a pretty massive balance system and calibration weights.  Quality calibration weights will cost in excess of $65.  What contest director/Nats R/C Aerobatics event manager is willing to fork out that kind of $$$$?

Ron Van Putte

> On Jan 28, 2017, at 11:32 AM, James Oddino <joddino at socal.rr.com> wrote:
>
> The point was that the limit is on the mass of the model not on the force it exerts due to gravity.  If you use a balance you will measure its mass (same on the moon) and not be affected by gravity and all of the stuff that affects force measuring devices.
>
> Jim
>
>
> On Jan 27, 2017, at 4:38 PM, Ronald Van Putte via NSRCA-discussion wrote:
>
>> I dunno.  I don’t planning on going there.
>>
>> Ron
>>
>>> On Jan 27, 2017, at 6:36 PM, James Oddino <joddino at socal.rr.com> wrote:
>>>
>>> What is the weight limit on the moon?
>>>
>>> Jim Oddino
>>>
>>> On Jan 27, 2017, at 2:02 PM, Ronald Van Putte via NSRCA-discussion wrote:
>>>
>>>> Typo in second paragraph.  Should have been 5000gm, not 50000gm.  Sorry.
>>>>
>>>> Ron
>>>>
>>>>> On Jan 27, 2017, at 3:57 PM, Ronald Van Putte via NSRCA-discussion <nsrca-discussion at lists.nsrca.org> wrote:
>>>>>
>>>>> Something has been nagging me since the 2011 F3A World Championships.  The decision was made, over the objections of the official weighers (John Fuqua and me), that airplanes would be allowed to weigh 1% more than the listed maximum weight of 5000gm, or 50gm.
>>>>>
>>>>> The argument was that it “allowed for possible inconsistencies in measuring equipment”.  We objected because we had purchased calibration weights and had them verified by the Precision Measurement Equipment Laboratory on Eglin AFB (at the cost of a sixpack of beer per set of calibration weights).  That meant we knew exactly what the airplanes weighed.
>>>>>
>>>>> Now to the current situation.  Currently, AMA classes have a 1% weight tolerance, or 50gm.  Suppose a contestant’s model actually weighs 5050gm, but the weighing equipment is in error by 25 grams.  So the scales would measure the contestant’s airplane at 5075gm.  Remember that the 15 allowance is for "possible inconsistencies in measuring equipment”.  The contestant’s airplane is “too heavy”.
>>>>>
>>>>> Something to think about.
>>>>>
>>>>> Ron Van Putte
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