erkki67
Well-Known Member
If I remember it right, Mr. Wickwire did use 3mm plywood sidepanels on his HM290 interpretation, with holes in the rear to save weight.
I'm enjoying your postings on the Flea - love your pioneering construction philosophy.I'm using West System epoxy. I thought of using T88, but the stuff is so bloody thick, it makes it difficult to work with. The West system is very runny, and goes on very easily with a squared-off tongue depressor.
It will work better /simpler, splitting the front wing .Update:
I can't find my original calculations for the additional "aileron" force which will be applied by deflecting the rear wing halves, so I can't verify the figure in the drawing above. So I re-did the calculations, and (of course) the differential aileron effect of pivoting the rear wing differentially is dependent on airspeed. It turns out that at cruising speed (78kts - which is wildly optimistic, I know), 0.5 deg of "aileron" movement amounts to 21kg per side. The trick will be managing such small incremental pivots. Linear actuators? Servos? A piggy-back lever on the rear wing bellcrank?)
The CG is about at your head . The front wing center of lift is about at your head. Bad. Have you 1/4 scaled this ? Has anyone run this on any sim? This is why I spread my wings apart, to move th4e pitch authority further from the CG.A picture is worth etc etc.
View attachment 106243
The CG has been very carefully worked out. The traditional method for calculating the proper CG was to at least start with it at 25% of the combined chord. I have written extensively on a more scientific way to establish the proper CG in my paper: Basically, the CG needs to be ahead of the combined centre of lift of both wings by some factor between 5% and 10% of the combined chord. As it turns out, the 25% rule isn't all that bad as a starting point.The CG is about at your head . The front wing center of lift is about at your head. Bad. Have you 1/4 scaled this ? Has anyone run this on any sim? This is why I spread my wings apart, to move th4e pitch authority further from the CG.