SPA3DT and airfoil quesiton
03-24-2004, 10:21 AM
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SPA3DT and airfoil quesiton
Morning fellow SPADDERS!!!
Built a SPA3dT and have a quesiton about the leading edge and airfoil.
I placed the battery and receiver under the folded back section of the leading edge. In doing so it bulges downward slightly. Will this downward bulge affect the flight performances of the plane ? I'm looking into doing the usual 3D type of flying with the plane.
On the plans it shows the battery under the folded part and the receiver zip-tied further back, not under the leading edge fold, but under the wing so it does not bulge the bottom down. Is the reason for doing it this way ?
One more question:
I also was able to put a MCM on a OS 46 FX, but to get the header and muffler to go underneath the wing, I had to mount the engine on the underside of the HPDE engine mount, not on top. The engine is still upright, just the screws mount from the bottom and screw into the HPDE.
Question here is-How will this affect the flight performance by the engine being set lower by 7/16" (the thickness of the HPDE mount) ?
I know the logical answer would be to fly it and find out, any input would surely be appreciated.
Thanks to all
Cary
Built a SPA3dT and have a quesiton about the leading edge and airfoil.
I placed the battery and receiver under the folded back section of the leading edge. In doing so it bulges downward slightly. Will this downward bulge affect the flight performances of the plane ? I'm looking into doing the usual 3D type of flying with the plane.
On the plans it shows the battery under the folded part and the receiver zip-tied further back, not under the leading edge fold, but under the wing so it does not bulge the bottom down. Is the reason for doing it this way ?
One more question:
I also was able to put a MCM on a OS 46 FX, but to get the header and muffler to go underneath the wing, I had to mount the engine on the underside of the HPDE engine mount, not on top. The engine is still upright, just the screws mount from the bottom and screw into the HPDE.
Question here is-How will this affect the flight performance by the engine being set lower by 7/16" (the thickness of the HPDE mount) ?
I know the logical answer would be to fly it and find out, any input would surely be appreciated.
Thanks to all
Cary
03-24-2004, 03:53 PM
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RE: SPA3DT and airfoil quesiton
Don't worry about the bulge or the low mounted engine, it'll fly fine.
Getting the CG in the sweet spot is the key for doing 3D stuff.
MrG>>>>>
Getting the CG in the sweet spot is the key for doing 3D stuff.
MrG>>>>>
03-24-2004, 07:03 PM
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RE: SPA3DT and airfoil quesiton
Thats where I start on the cg. I now have it moved back to 7". Many people have mounted their engine on the bottom and it works fine. I mount mine at 90 degrees.
William
William
03-25-2004, 12:40 AM
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RE: SPA3DT and airfoil quesiton
Don't worry about the bulges. I was a bit over-zealous with the expandable foam on my latest project, and the leading edge looks as if it's ready to pop. But guess what - it flies great! Just remember, these are $15.00 plastic and aluminum planes. They are not $2000 TOC composite pattern planes. They are not 200mph pylon racers (not yet anyway). But they are one of the most gratifying projects you'll ever complete, and possibly the most fun you'll have flying an RC plane. The most important thing is don't sweat the small stuff. If your wing loading is okay, the incidence is set up properly, and the CG is correct, you cannot go wrong.
