Posted 14 Jan 2023 (edited) Going to start scratch building speed wings soon, for my fat airframe.Current thoughts are avid speed wing airfoil, 12 inch rib spacing,.083 spars @ 12 foot, 7/8 inch lift struts. Essentially longer aerobat wings.For current speed wing/aerobat pilots, are there any modifications you would have liked?Different airfoils, kitfox? just aircraft? Longer / shorter spars? Slats? Speed brakes? Anything come to mind? I'm scratch building so anything goes!Goal of 120mph cruise, planned Yamaha sidewinder firewall forward Edited 15 Jan 2023 by Airplanenate fixed tags Share this post Link to post Share on other sites
Posted 14 Jan 2023 Kitfox 4 and later style ribs may be a better option, they perform good at slow and higher speeds. Also, it may be hard to find .83" tube for spars. Kitfox uses .065" and a good stiffener with gross weights of 1550 lbs. 120 is pretty fast for these planes... 2 people like this Share this post Link to post Share on other sites
Posted 14 Jan 2023 X2 on the Kitfox Ribs. Definitely the best design of the segment for overall performance. You may need to get them from another builder or make them yourself, unless you buy a complete wing kit.Investigate the .083" tubes more. There is a local metal supplier near me that can get both .065" and .083", but only in 20' lengths (lots of waste and therefore expense). With the thick wall tube, the Just Aircraft extruded inserts become an option. Getting the Kitfox inserts (for the .065") may be problematic. I've heard they will not sell to anyone without a serial number due to supply limitations. 1 person likes this Share this post Link to post Share on other sites
Posted 15 Jan 2023 About 6 yrs ago, I was going to get a spar tube from Just Aircraft to repair a Kitfox 1 wing I had. It was .065"wall, and they said they would install the aluminum stiffener in it for me to avoid extra shipping. Based on that, I thought Just used the .065" material. Maybe they went to the .083" stuff later on??? I ended up finding another complete wing that needed some repairs and used it instead. Made quite a sight driving it back from New York state to Mn. 1 person likes this Share this post Link to post Share on other sites
Posted 15 Jan 2023 Kitfox 4 and later style ribs may be a better option, they perform good at slow and higher speeds. Also, it may be hard to find .83" tube for spars. Kitfox uses .065" and a good stiffener with gross weights of 1550 lbs. 120 is pretty fast for these planes...I should have mentioned, I already have the 0.083" spars. Is KF4 better than newer versions? 5? 7? I don't really need best of both worlds, I have a set of stol wings that will get rebuilt in the future. but i don't want it to fly like a lead balloon either.... yours is more impressive, i only had the spars up top. Share this post Link to post Share on other sites
Posted 15 Jan 2023 Kitfox 4 and later models use the same ribs. STi wing is different though. Nice thing about the Kitfox 4 is it's lighter than later models. They are bigger, and have higher gross weights however. Share this post Link to post Share on other sites
Posted 16 Jan 2023 Kitfox 4 and later models use the same ribs. STi wing is different though. Nice thing about the Kitfox 4 is it's lighter than later models. They are bigger, and have higher gross weights however. Very intriguing proposition...... Share this post Link to post Share on other sites