# Figuring c of g on a biplane?

• posted
Anyone have a link to a site or, can just explain how to figure the balance on
a biplane. I can find the MAC of a wing and the balance point at whatever
percentage or range I need. But I need to know how the two wings of a bipe or
several wings would be mathematically leveraged to find the balance point.
Fred
• posted
on Alans website.. a folder shows this address to try..
ALANS SITE
-- T. Dell Shannon President, Osceola Propbusters AMA 709192 IMAA 28590
• posted
Hi Fred, Some good jpegs sent direct, especially with regard to biplane decalage. Some recently said that all info should be on responded to on the newsgroup but if to much is posted those same people then sing a different song.. regards Alan T. Alan's Hobby Web Links

• posted
Throw the math away, here's an easy way to get into the ball pack for safe test flying. Use the top view of the two wings (two constant chord wings) and draw a line from the top LE to the bottom TE and use that horizontal distance as the MAC. Basically just add the stagger amount to the top wing chord and Balance it at the 25 to 30 % point. For a biplane with a swept back top wing and a straight bottom wing, treat the top view of both wings as if it were a tapered wing panel and find the MAC that way. Check out my April 2002 Thinking Big Column for more info and some neat illustrations.
Several people have now used this method and it works great! It even helped someone balance a Fokker Triplane! Cheers, GY
• posted
Thanks for hthe help everyone!
Fred
• posted
As Ed implied indirectly, there are whiney brats EVERYWHERE these days!
• posted
We used to have some rather simple rules for these things. Binary stuff should normally not be posted (i.e. no attachments), but made available on a web or ftp server if possible, or sent directly to the recipient if necessary. Apart from that, the default should be to respond in the group (or on the mailing list) where the question was asked. However, if the question is of interest to very few of the subscribers, or will generate very large amounts of information in the answers, the person asking the question may request that replies go directly to him, and he will post a summary of them later.
These days, of course, there are no rules. :-)
-tih

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