> In the past I have used .014 pre-preg for the upper spar and > .007 for the lower.
For a plane the size of the Challenger, these thicknesses are about 1/3 of what is actually needed. Use .042 on top and .021 on the bottom. > Ideally, placing the CF in the middle of the upper spar would > provide great strength, but placing it under the spar Put it on top. The distance between the top and bottom carbon strips must be as great as possible. For very complete discussions of carbon in spars, see the Charles River website, or the Allegro Lite Yahoo Group archives. You can find the math to figure out the right dimensions, along with extensive construction notes. RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
