Bonzo Moon Posted November 24, 2020 Share Posted November 24, 2020 My no.6 Lidl glider RC conversion, this time a biplane! Complete build blog. And the maiden, which didn't go well. I discovered I hadn't got prop thrust angle right! Quite pleased with it and I'm hoping now I've added down thrust it'll fly well on my next test flight Quote Link to comment Share on other sites More sharing options...
MattyB Posted November 24, 2020 Share Posted November 24, 2020 Nice work, but why are the interplane struts so tall? Seems like they could have been 50% shorter and it might have looked a little more elegant. Also whilst the thrustline is obviously wrong it looked to me like it might be tail heavy too - I would be tempted to try a power off test glide over long grass to check itbefore trying another powered flight. Good luck! Quote Link to comment Share on other sites More sharing options...
Bonzo Moon Posted November 24, 2020 Author Share Posted November 24, 2020 Posted by MattyB on 24/11/2020 10:59:53: Nice work, but why are the interplane struts so tall? Seems like they could have been 50% shorter and it might have looked a little more elegant. Also whilst the thrustline is obviously wrong it looked to me like it might be tail heavy too - I would be tempted to try a power off test glide over long grass to check itbefore trying another powered flight. Good luck! Agree it looks tall but I Googled biplanes and it's suggested that the gap should be the same as the chord, which is what I went for. It's the same on the Flight Test foam board SE5 Biplane. Does look a bit ungainly though! Google said biplanes don't generate twice the lift of a single wing mostly because of the airflow between wings, hence it improves with a big gap! Quote Link to comment Share on other sites More sharing options...
Bonzo Moon Posted November 24, 2020 Author Share Posted November 24, 2020 From Google Biplane Gap & Stagger Abstracted by Mike Nassise Gap and stagger are a pair of terms used to describe a biplane's layout which a modeler should well understand when building a multi-wing mode/- Editor. The gap on a biplane is the distance between the two wings. It is measured as the vertical distance between the chord lines of the two airfoils. All biplanes must, obviously, have a certain gap and, in general, this should be as large as possible. For satisfactory flight efficiency a minimum figure is usually stated as gap:' wing chord (or chord of the largest wing if these are of unequal size). There is no theoretical upper limit, but above a gap of about 1.5 the max chord, each wing acts as a single monoplane wing with no inter-wing interference. Quote Link to comment Share on other sites More sharing options...
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