What’s the real world performance gains over the standard tips for the Bearhawk models that have them? Not disputing the Hoerners are better, just trying to gage whether the juice would be worth the squeeze, so to speak?
The thing I like about hoerners is that they increase the effective wingspan. With rounded tips air spills from the bottom of the wing up and onto the top of the wing shortening the effective span. Hoerners eliminate this spillage. Plus they look cool.ðŸ˜
Cutting the foam block and forming the tips is actually quite easy. We ran into trouble when making the molds which is when I threw in the flag and slapped spill-plate tips on our plane. My pops has started making new foam plugs and a local guy said he’d make us molds and carbon tips for a reasonable amount. After kicking the idea around we decided to skip the molds and just make if one-off set of tips using the plugs.
Also, I made some patterns for making aluminum hoerner tips that I think would be very close to as clean as fiberglass tips. The compound curve at the leading edge was challenging so it is a little dirty but I think it could be worth pursuing. I stopped when I make forms for tip ribs and hat sections to stiffen things up.
Scratch Built 4-place Bearhawk. Continental IO-360, 88" C203 McCauley prop.
An article that compares three wingtip shapes (Square, Round, and Hoerner) in a wind tunnel may be found on Page 38 of Sport Aviation Magazine, Feb 1971 for those who are EAA members. I'd be interested in your feedback.
My opinion is Wind Tunnel data is data, but not real life data. However, Battson's report seems to me to confirm its findings. The square tip is a flat square, unrounded shape. I've shared before my curiosity of the wingtip Steve Wittman used on his W-10 Tailwind design. I think it ugly but I also think Wittman tested things on real airplanes. Whee might be surprised by his square tip performance. Mooney likes the square tip.
For STOL performance tip plates probably work 60 to 90% as well as something more complex, at the cost of drag. Hoerner tips are not that different than tip plates, with a big fairing between the wing and the plate.
Having done a lot of research, this is true for LSA / microlights ^
For heavier aircraft with double (or more) induced drag at the tips, the differences show.
Bolting either kind of wingtip onto a standard Bearhawk wing, a tip plate and 16" aerodynamic hoerner wingtip will be chalk and cheese. The increased span alone makes a huge difference, before considering the shape factor.
I do think that a better tip helps an airplane like a BH more than a high aspect and/or tapered wing. A larger percentage of wing area is affected than a tapered/elliptical/higher aspect wing.
Better tips I would buy if I could now because I haven't installed the kit tips yet., but they are farther down the improvement list if I have to make my own. Lighter doors are probably #1 after I get 'er flying.
I had to look up the meaning of "Chalk and Cheese." It means the two are very different from each other...nothing in common. I suspect others might wonder too.
I posted this earlier today to check for collective interest. I am nearing to needing to make a decision and made the call to a potential economical provider
whee posted about a new Horner wingtip from D & E, I just got off the phone with D & E and they currently do not have a wingtip for the Riblett 30-4135, they do have one with a slightly higher profile, but…. He is checking to see if his mold builder can/would be willing to build for the 30-4135.
His price is $1000.00
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