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Old Dec 24, 2012, 03:55 PM
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On bagged Supras it was definitely better with more reflex for the zoom. Molded Supras also benefit, but not to the same extent from what I recall.

Tom
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Old Dec 30, 2012, 05:16 PM
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United States, CA, Midway City
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Originally Posted by Francesco View Post
Mmmh as far as I can remember, the Supra airfoil was known for being in optimal reflex when the bottom was flat.
Hi Francesco, on the molded Supra, for zoom speed it was actually -.5 degrees in reflex and not quite flat bottomed.
Cruise was 2 degrees camber, and penetration was with .5 degrees camber so there was a 1 degree reflex difference between fast flying vs zoom.

On the Maxa, there is also about a 1mm flap setting difference between fast horizontal flying ( penetration mode) and zoom speed. Penetration is with wing flat bottomed and adding an extra mm reflex to this would yield better performance for zoom speeds.

However, I think adding a bit more might be better as Kyle experienced because of the droop nose. The added reflex beyond optimal causes the wing to fly at just slightly less than "no lift" = negative lift which keeps the fuse more inline with the airflow. Just my hunch based on other planes I have tested .
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Old Dec 30, 2012, 06:37 PM
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Originally Posted by fnnwizard View Post
Hi Francesco, on the molded Supra, for zoom speed it was actually -.5 degrees in reflex and not quite flat bottomed.
Cruise was 2 degrees camber, and penetration was with .5 degrees camber so there was a 1 degree reflex difference between fast flying vs zoom.

On the Maxa, there is also about a 1mm flap setting difference between fast horizontal flying ( penetration mode) and zoom speed. Penetration is with wing flat bottomed and adding an extra mm reflex to this would yield better performance for zoom speeds.

However, I think adding a bit more might be better as Kyle experienced because of the droop nose. The added reflex beyond optimal causes the wing to fly at just slightly less than "no lift" = negative lift which keeps the fuse more inline with the airflow. Just my hunch based on other planes I have tested .
That's curious, as I am not aware of a change in the airfoil between Dr. Drela's bagged Supra and the molded one.

Do you have a Maxa, Tuan? It'd be interesting to share our settings. Personally I think that 1 mm difference is too low to get to the minimum drag point. I think I have closer to 4 degrees difference. Plus, anything of that order of magnitude is likely to be "masked" by the linkage and servo slop. May be placebo, but nothing real.
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Old Dec 30, 2012, 09:33 PM
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Originally Posted by Francesco View Post
That's curious, as I am not aware of a change in the airfoil between Dr. Drela's bagged Supra and the molded one.
The airfoil isn't different. Surface finish/smoothness is. From what I recall, the higher reflex numbers are driven by getting a Cl as close to zero as possible. Based on discussions with Mark, the higher reflex was more important for the not as smooth bagged wings. It should help the molded wings as well.

There was a significant difference in zooms with the additional reflex on my Supras - easily seen from the ground. So I would expect that if the Maxa has similar characteristics, it should be noticeable by trying different reflex settings for the zoom. It appears that Kyle already found this to be the case . . .

Tom
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Old Dec 31, 2012, 12:03 AM
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United States, CA, Midway City
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Originally Posted by Francesco View Post
That's curious, as I am not aware of a change in the airfoil between Dr. Drela's bagged Supra and the molded one.

Do you have a Maxa, Tuan? It'd be interesting to share our settings. Personally I think that 1 mm difference is too low to get to the minimum drag point. I think I have closer to 4 degrees difference. Plus, anything of that order of magnitude is likely to be "masked" by the linkage and servo slop. May be placebo, but nothing real.
No, I do not have Maxa. I am contemplating on getting 1. The 1mm is not from my observation, just from Vladimir's site. I cut and paste the speed settings below and included the pdf.

SPEED template
That template is for transition flying from one lift to another,
for returning from distant lift back, or for flying in high wind
conditions/environments. Speed setup could be applied by slider
first extreme position, or/and by assigned switch.
For best zoom performance we recommend to add 1mm more up
setting.
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