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Old Jun 19, 2012, 01:11 PM
nomadic80 is offline
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Joined Dec 2010
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Thrust angles & relative factor's

I decided to start this thread due to many threads with contradicting statements.Thrust angles on a puller are a given.I'm more interested in pushers.Almost all commercial high mounted pushers have the prop end up a little.I have heard this is mainly to counteract nose up during throttle or to lessen the distance between CG and thrust angle,therefore reducing pitch change.However I have also read that having horizontal stab in the prop wash on a high mounted pusher has a greater nose up effect than just pointing the prop end up.Im still a noob and always learning.I'm mainly writing this thread because I finished a scratchbuilt pusher which has an extreme thrust angle(16deg),due to location of tail boom.It was originally intended to have an EDF on top of the wing so prop clearance wasn't an issue before.I think the lift factor from the wing and the downforce on the tail from the small t-tail section will counteract the nose down tendency on my high mount pusher.When perched on a CG stand she noses down with throttle so I'm hesitant to give her a glide test because I'm scared she'll nose in.I followed formulas on adamone rc and used CG calculator's so I think I got everything else right.Just curious,does she look airworthy, even with the thrust angle?Any suggestions,or opinions are greatly appreciated.While I'm here,which way should a pusher prop mounted above CG point?Prop end up or prop end down?
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