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Knoll53's blog
Posted by Knoll53 | Oct 11, 2014 @ 05:48 PM | 1,064 Views
Spent a few hours trying to be a hero and fly with a high performance aft CG, then moved the CG forward to find a better handling plane. Elevator throws reduced to minimum. Nice little hyper stall with flaps and full nose up.

Posted by Knoll53 | Oct 10, 2014 @ 12:48 AM | 1,147 Views
Pulling back with full flaps is not such a smooth ride.

Posted by Knoll53 | Oct 06, 2014 @ 12:20 PM | 1,524 Views
With the potential of lots of highly cambered wing, this one could be a floater, even at 10oz. /s.f.
Posted by Knoll53 | Oct 05, 2014 @ 06:43 PM | 1,972 Views
Flaps are working great now.
So rekit #7 has stretched out the flaps to be full length which requires a bit of nose down mixing with the elevons. There was just a little too much nose down for these flights, which is the safe way to go. This configuration works great. It can fly slow now with flaps and can pull a high angle of attack for final landing flare. As originally hoped for, the flaps provide higher lift at a slower speed.....
SW-7.......... full length flaps (1 min 18 sec)

Posted by Knoll53 | Sep 24, 2014 @ 11:04 AM | 1,265 Views
I'm finding some advantages to full length flaps which are pitch positive.
Posted by Knoll53 | Sep 13, 2014 @ 07:22 PM | 1,570 Views
Final round of flap testing after they were lengthen towards the root by over and inch. Pitch response is a problem with flaps. Even modest nose up input causes a stall. If flies OK without flaps.

Razor's Edge - Flap test after body work (3 min 57 sec)

Posted by Knoll53 | Sep 07, 2014 @ 07:03 PM | 1,798 Views
3rd sighting in 6 weeks of a pack of 3 California Condors. Most video lost to auto focus. One of them dropped out and landed while the other 2 disappeared into the distance for 20 minutes, then they returned and soared around the perched one. I left after 1/2 hour and the perched one was hanging tough.

California Condors at Garrapata State Park (2 min 30 sec)

Posted by Knoll53 | Sep 01, 2014 @ 07:22 PM | 1,393 Views
Flying in calm conditions finally settled on 5% static margin for the most aft safe CG. At nearly 12 oz/s.f. and a 4" airfoil, that's about as daring as I get. The flaps proved to induce a little nose down in the calm conditions, which made it difficult to fly with a high AoA for final flare. This plane needs to move even with flaps. I'll add an inch to the flaps before final finishing. Nickels formula was not that far off.

Soberanes, no wind. no thermal, so lots of testing (6 min 13 sec)

Posted by Knoll53 | Aug 31, 2014 @ 09:44 AM | 1,549 Views
Final layout with field tested "nearly" pitch neutral flaps.
Posted by Knoll53 | Aug 30, 2014 @ 11:03 PM | 1,723 Views
Today found a little choppy lift and just put the nose down a bit and let it cruise............this plane is much happier when it's moving. The flaps are 2" shorter now and happily are pitch neutral. They are an absolute requirement for a wing this skinny. There is a learning curve for the tiny flight envelope, but I'm beginning to get it.

Razor's Edge in choppy lift (2 min 1 sec)

Posted by Knoll53 | Aug 24, 2014 @ 07:33 PM | 2,076 Views
Down right windy today which apparently make the local wildlife frisky.
Air Plank and the hawk (2 min 14 sec)

Posted by Knoll53 | Aug 24, 2014 @ 07:04 PM | 1,979 Views
Again some condors flew through in mid afternoon. Only got a few glimpses with the new camera.
California Condor & Air Plank (1 min 21 sec)

Posted by Knoll53 | Aug 23, 2014 @ 11:28 PM | 1,752 Views
Posted by Knoll53 | Aug 17, 2014 @ 08:11 PM | 1,914 Views
Posted by Knoll53 | Aug 17, 2014 @ 07:40 PM | 1,872 Views
Toyed around with a variety of CGs and elevator throws today in the calm hot air of Soberanes Point. The best performance and elevator response is with a very aft CG which brings less than stable handling, but so far, that is my comfort zone with this plane. This flight has the aft CG and you see that it is not exactly on rails. Video cut short due to autofocus problems. Going all manual focus next time.

Razors Edge at Soberanes (0 min 33 sec)

Next up to completely glass the wing in order to combat flutter.
Posted by Knoll53 | Aug 16, 2014 @ 11:44 PM | 1,992 Views
Found an hour today before work and got some testing in after the flap and pod rekit. Nice calm conditions at 9am. Had to rework the CG because the reference mark was lost. Trying different CGs today shows that this plane really performs better with an aft CG. Also, the tip stall is not a problem with a forward CG and IS a problem with the high performance aft CG.
First Bungee (4 min 57 sec)

Short story is that the flaps are pitch positive, as in a lot of nose up. After a few flights, settled on 15% down elevator mixed into flaps to tame things down but am surprised the Nickels formula is so far off. Checking my work now.
...Continue Reading
Posted by Knoll53 | Aug 12, 2014 @ 08:23 PM | 1,888 Views
After a few flights, it's clear that if any wing could benefit from flaps to slow the action down, it is this one. New servos are on their way.....

If it turns out that the flaps mitigate the stall behavior, I'll mix them into the elevator.

Flap sizing based on Nickel's formula.
Posted by Knoll53 | Aug 10, 2014 @ 04:48 PM | 1,914 Views
As expected, this tiny thin wing is not shy about stalling and falling out of the sky. The flight envelope is plenty big, but when it DOES spins you had better be ready. Today proved that it will spin to left every time. Flying with a light touch on the elevator is the solution. The elevator response is very response for a swept wing so I think that the CG is back far enough. For awhile, flew with 2 quarters taped to the nose and performance was noticeably less, i.e. could not soar these light conditions.

Razor's Edge light lift (2 min 27 sec)