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  #1  
Old 07-08-2011, 04:49 PM
JFRV8 JFRV8 is offline
 
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Location: Anchorage, AK
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Default RV-8 W&B Spreadsheet

Here is a Weight & Balance Spreadsheet I generated. It is in Excel and can be edited for you airplane's numbers (just turn Protection Off).

If you want a copy, send me a PM.

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  #2  
Old 07-10-2011, 02:03 PM
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Toobuilder Toobuilder is offline
 
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Location: Mojave
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Default

Nice! I also developed a spreadsheet (but yours is less "busy").

In mine, the grey boxes are editable, and the results update through the excel magic. It also updates the aerobatic, normal, or out of limits based on green, yellow or red. In the example shown, I am only within aerobatic weigh limits at near zero fuel (green), but still outside the aerobatic CG even at empty (yellow).






I did notice a difference in the arm for your wheels. I measured 69.75 to your 68, (not a huge deal) but significantly, I get 251.625 to your 240 - a whopping difference! Did you measure in the 3 point or level attitude? If we have essentially the same airplane, your forward bias looks like it was measured on the floor in a 3 point. Plugging in your tailwheel arm number (240) moves my CG forward a half inch. I guess I better jack mine up and re-do the measurements to make sure.
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WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.

Michael Robinson
______________
Harmon Rocket II -SDS EFI instalation in work
RV-8 - Flying
1940 Taylorcraft BL-65 -flying
PA-20-inspired "family truckster" -in work

Last edited by Toobuilder : 07-10-2011 at 02:21 PM.
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  #3  
Old 07-11-2011, 07:18 AM
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Alan Carroll Alan Carroll is offline
 
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Quote:
Originally Posted by Toobuilder View Post
Nice!

I did notice a difference in the arm for your wheels. I measured 69.75 to your 68, (not a huge deal) but significantly, I get 251.625 to your 240 - a whopping difference! Did you measure in the 3 point or level attitude? If we have essentially the same airplane, your forward bias looks like it was measured on the floor in a 3 point. Plugging in your tailwheel arm number (240) moves my CG forward a half inch. I guess I better jack mine up and re-do the measurements to make sure.
Michael - I have 68.75" for my mains. If apply this number to your weights it moves the aircraft CG forward about an inch. Perhaps these measurements are related to your mysterious aft CG change following rebuild?
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  #4  
Old 07-11-2011, 11:57 AM
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humptybump humptybump is online now
 
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Default iPhone app

For iPhone users (and probably Android), I wrote a web app - http://53vg.com/wb

If you bookmark it to you smatphone's home screen, it caches itself and no longer requires a data connection. It also remembers the values from your last calculation so once you enter you fixed values, they "stick". I wanted something so convenient, I'd use it for every trip and every passenger.
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Last edited by humptybump : 07-20-2013 at 03:48 PM.
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  #5  
Old 07-11-2011, 12:21 PM
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Toobuilder Toobuilder is offline
 
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Quote:
Originally Posted by Alan Carroll View Post
Michael - I have 68.75" for my mains. If apply this number to your weights it moves the aircraft CG forward about an inch. Perhaps these measurements are related to your mysterious aft CG change following rebuild?
Thanks for the data point Alan.

I did keep the same measuremnts for both before and after, so that should have remained a constant.

Question - you measured in the "level" attitude, or 3 point? Also, what was your tailwheel arm?

I will certainly be measuring again!
__________________
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.

Michael Robinson
______________
Harmon Rocket II -SDS EFI instalation in work
RV-8 - Flying
1940 Taylorcraft BL-65 -flying
PA-20-inspired "family truckster" -in work
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  #6  
Old 07-11-2011, 04:29 PM
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Default yes

I would like a copy please. Thanks in advance. Looks very good.

tcb328@suddenlink.net
tim
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rv8 entire airframe at airport now, painting done, intersection and gear upper and lower fairings done, maybe order engine around first of year or before the next rate increase.
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  #7  
Old 07-11-2011, 04:51 PM
APACHE 56 APACHE 56 is offline
 
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Default Me too...

Please send me a copy Jon.

donstiver@earthlink.net

Thanks,
Don
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RV8 "Little Pill" N6371S, Merritt Island, Fl.
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  #8  
Old 07-11-2011, 04:53 PM
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Alan Carroll Alan Carroll is offline
 
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Quote:
Originally Posted by Toobuilder View Post
Question - you measured in the "level" attitude, or 3 point? Also, what was your tailwheel arm?
Its been a while but I'm pretty sure it was with longerons level. I have 251 for the tailwheel.
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RV-8 N12AC
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  #9  
Old 07-13-2011, 07:13 PM
JFRV8 JFRV8 is offline
 
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Default Change the N Number

Thanks everyone for the responses on the spreadsheet.

You can change the N number in the graphic since it is in a textbox. Just turn Protection off first so you can select the text box.

The weights and arms are based on typical numbers from other RV 8's. I have not measured and weighed mine yet.

Jonathan

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  #10  
Old 07-19-2011, 09:21 PM
HawkinSF HawkinSF is offline
 
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Default Love a copy...

Sure would like a copy also... Thank you!

J. Hawkins
hawk@gofarmers.com
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