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Hello,
I've been watching for a while, have done some searches, and would now like suggestions for an airfoil.
I'm considering building something like a Strojnik S2A. The S2 uses the Wortmann FX 67-170/17, which appears to be a fairly standard all around airfoil that's been around some 30+ years.
I am concerned about the need to be very precise with laminar airfoils and this one in particular.
I'm looking for an airfoil that will tolerate a little lack of precision.
These are my priorities and areas for trade off:
Some toleration of imprecision in constructing the actual wing/airfoil
Good L/D as everyone
Low sink rate
Good lift in poor conditions
A slow stall speed (I know that this usually involves more wing area)
A smooth stall
Stability and lack of pitching
Top speed--willing to sacrifice in this area while wanting to maintain reasonable penetration as the conditions where I would fly are often windy.
Something not too exotic, that is something for which the profile coordinates are easy to find.
A while ago there was an article where Udo Rumf did some modifications on the same airfoil in an HP-18 believing that the FX 67 required too much precision to obtain its best performance--he modified the FX 67 to a [FONT=Times New Roman, Times, serif][SIZE=+1]Marsden's UAG88-143[/SIZE][/FONT]
SUPER HP-18
I prefer using more wood and fewer composites.
Any suggestions?
Stan S
I've been watching for a while, have done some searches, and would now like suggestions for an airfoil.
I'm considering building something like a Strojnik S2A. The S2 uses the Wortmann FX 67-170/17, which appears to be a fairly standard all around airfoil that's been around some 30+ years.
I am concerned about the need to be very precise with laminar airfoils and this one in particular.
I'm looking for an airfoil that will tolerate a little lack of precision.
These are my priorities and areas for trade off:
Some toleration of imprecision in constructing the actual wing/airfoil
Good L/D as everyone
Low sink rate
Good lift in poor conditions
A slow stall speed (I know that this usually involves more wing area)
A smooth stall
Stability and lack of pitching
Top speed--willing to sacrifice in this area while wanting to maintain reasonable penetration as the conditions where I would fly are often windy.
Something not too exotic, that is something for which the profile coordinates are easy to find.
A while ago there was an article where Udo Rumf did some modifications on the same airfoil in an HP-18 believing that the FX 67 required too much precision to obtain its best performance--he modified the FX 67 to a [FONT=Times New Roman, Times, serif][SIZE=+1]Marsden's UAG88-143[/SIZE][/FONT]
SUPER HP-18
I prefer using more wood and fewer composites.
Any suggestions?
Stan S