> "For anyone using a belly board on their KR's . . ."
Joe, when I first got my plane from Steve I looked into the "holes vs solid" question and learned that the dive bombers such as the Douglas SBD used holes in the flaps to reduce weight and, more importantly, to reduce aerodynamic stress related to turbulance in the dive. Seems like having holes would create _more_ turbulance, but my memory (such as it is) tells me the holes were used primarily to reduce turbulence in the dive. Controllability issue as I recall. Mine (Ken Cottle's) came with holes. After concluding from what I'd read and heard that a solid flap would be more effective, I taped over my holes with some heavy duty tape to see if I could tell a difference. It seemed to be more effective with the holes covered. The tape didn't last long and I planned to cut some plugs to match the circles and thus restore the flap to a solid plane, but the improvement was so small I never got around to it. My fuselage is only 24" wide and my flap only extends to 30 degrees so using belly board or not using it doesn't make much difference, although I always do use it. Flying Jim Morehead's full-width KR-2 with a belly board (no holes) was not only wider than mine but in addition, extended to 45 degrees (or perhaps a bit steeper - can't remember) and was extremely effective. Landing his tri-gear KR with belly board fully extended was an exquisite pleasure, allowing a very steep and slow approach.. His extension mechanism was much more rugged than mine. On 3345KC Ken had used a fairly flimsy extension mechanism that someone, perhaps Rand, had designed. I've seen the same design on other KR's. It works, but Jim's design was far better. BTW, these belly boards also lower stalling speed by a little, adding lift as well as drag, so are really nice to have. I assume you've got conventional flaps on your already-built aircraft. ******************* A truly ideal design would be split flaps, or even normal hingeflaps, but linked to a belly board. The design seen on the Mustang II or DC-3 or Cessna 310 is what I'm referring to, although the term belly board doesn't exactly apply with those planes.. >From what Sparky has mentioned regarding the effectiveness of his stub wing hinged flaps, he says they hardly make any difference. A large, steeply angled belly board such as Jim Morehead had works extremely well though. I'd forego the holes. Mike KSEE ____________________________________________________________ Sponsored by https://www.newser.com/?utm_source=part&utm_medium=uol&utm_campaign=rss_taglines_more 'We Will Not See His Like Again' http://thirdpartyoffers.juno.com/TGL3141/5fd6c32387ea643231797st01vuc1 Wisconsin Justice Takes Trump Lawyer to Task http://thirdpartyoffers.juno.com/TGL3141/5fd6c323ab61143231797st01vuc2 US Treasury Gets Hacked, Sources Say http://thirdpartyoffers.juno.com/TGL3141/5fd6c323cf7e943231797st01vuc3 _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/[email protected]/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to [email protected]
