Weight problems

[Doakes]

I think this is the right place to ask.

I weighted my aircraft 7A and it weighted 438 on each rear wheel and 265 on the nose. My CG are a bit aft. I did not put extra stuff in the plane in fact I have 2 SVs and 1 radio and intercom. Avery seats and auto pilot, ADAHR, and a box for the Strobes. That is all.
My question to those who have flying 7A, is your CG's within the manuals' specs?
Thanks
Dave

[RVNewsletter]

I suspect you don't really have a problem. Your numbers are pretty much dead on. 1111 is about 10 pounds lighter than the sample aircraft in Van's manual.

You say your CG "are off". Explain. What's your datum point for measuring CG location? (tip of the spinner?)

"A bit aft" doesn't really tell us much. Do you mean your CG is aft of the sample? How much aft?

You should probably post your weight and balance calculations empty, gross weight, and full fuel with 100 pounds of baggage and it'll be easier to see if you have a problem.

[newtech]

My question to those who have flying 7A, is your CG's within the manuals' specs?
Thanks
Dave

I followed Van's suggestions and built my 7A light. 18 lb. Catto prop, light weight starter, parallel valve O-360, etc., etc. Even with 5/8" spacers between the engine mount and firewall I still have 32 lbs. of dead weight on the nose to get the CG in comfortable limits. The 32 pounds is a Saber 20 lb crush plate and a 12 pound harmonic damper.

The 7A was designed to be in the CG sweet spot with an angle valve 360 and constant speed prop.

[Doakes]

I do not have my figures with me they are at the airport. I will get them tomorrow and post my examples.
Dave

[Doakes]

How do I post a file with my data? i tried Photobucket and it seems that nothing on the site will work for me.
Dave

[Doakes]

Here are some of the results:
Main left wt. 438.8
main rt. wt. 438.8
Nose wt. 265.4

total: 11433
Moment: 92839.07
Empty C.G. = 81.22

I a out of C.G. using the examples in the builders manual at situations of:
Most AFT CG Gross wt minimum fuel
GW heavy pilot and baggage reduced fuel
GW heavy pilot and baggage minimum fuel

I can make these figures work by reducing the baggage wt from 100 lbs.
But the DAR wants me to re-weight the plane. So I guess that is what I will do.
Thanks much,
Dave

[Spike]

Both main wheels having threw exact same weight sounds a bit fishy to be honest.  I wonder if there was a glitch somewhere.

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-----Original message-----

From: RB Lists - RV7 <support@rivetbangers.com>
To: rv7@rivetbangers.com
Sent: Sat, Nov 24, 2012 12:07:55 GMT+00:00
Subject: Weight problems


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Here are some of the results: Main left wt. 438.8 main rt. wt. 438.8 Nose wt. 265.4 total: 11433 Moment: 92839.07 Empty C.G. = 81.22 I a out of C.G. using the examples in the builders manual at situations of: Most AFT CG Gross wt minimum fuel GW heavy pilot and baggage reduced fuel GW heavy pilot and baggage minimum fuel I can make these figures work by reducing the baggage wt from 100 lbs. But the DAR wants me to re-weight the plane. So I guess that is what I will do. Thanks much, Dave rivetbangers.com - Discussion topic http://www.rivetbangers.com/forums/viewtopic.php?p=40688#40688

Submitted via email

[Doakes]

Spike,
It may be my weights are off. I will re-weight the plane sometime soon.
Thanks for the thoughts
Dave

[Doakes]

Re-weighted my airplane and the total was about the same 1142 lbs empty.

Nose 276
Wheels: 431 and 435
My DAR was happy and but I had to placard the baggage bay with max 50 lbs.
He inspected the airplane and the N1243A is air worthy.
However, I could not fly, because of weather before I left for Florida.
So, until sometime in March it will sit and cry. Me too!
I hope to attend at Sebring on January 17 LSA Expo. Maybe I will see someone from this forum?
Happy New Year to all!
Dave

[Spike]

Very cool!


Spike