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May 26, 2019, 09:32 AM
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EdSoars's Avatar
What's your thinking about that billboard fin?
Looks like way more area than you need.
Lots of nose weights: fishing sinkets are the right equipment when trolling for lift...
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May 26, 2019, 10:26 AM
Everything's A Composite
Knoll53's Avatar
Thread OP
If you calculate the tail volume, something like moment arm x tail area, I think that it is comparable to my other planks. The moment arm from the CG is very short. With that said, this plane has very good yaw stability, so yes, there is a lot of tail. Also the very low aspect ratio of the fin makes it less effective. The tip losses of the fin start immediately.

There is a lot of heavy wing behind the CG. Those backed wood veneers are anything but light. Happily there is enough nose to stuff with lead to get the right CG. In this case, 10.8 oz. of lead. Loving the wing loading. I guess the coastal lift is at it's yearly high point now, so maybe less loving come August. But for now, I can fly everyday.

Looking forward to getting the ballast box glassed to see what a little added wing loading will do. I am still in the break and repair phase with this plane.
May 26, 2019, 10:38 AM
Everything's A Composite
Knoll53's Avatar
Thread OP
I could imagine a fin trim.

I am warming up to an all black central panel/fuse/fin with some sort of treatment for LE.
Maybe "hollow" graphic tape for the leading edge.
Last edited by Knoll53; May 26, 2019 at 11:14 AM.
May 26, 2019, 12:39 PM
You know nothing....
Stuart A's Avatar
“Cleaver” would be a good name for a wing.
May 27, 2019, 06:45 AM
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EdSoars's Avatar
I'm not sure... adding weight to overcome drag?
I just KNOW there's a graceful fin hidden within the Cleaver.
Still, your videos are proof of good handling.

Peter Wick is a fan of short tail moments, and the Amokka has what looks like a small fin volume, to me anyway.
And the Amokka flies like a dream.
May 27, 2019, 10:08 AM
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Knoll53's Avatar
Thread OP
Look at the tiny little elevator he has.........ha, ha, ha...............Oh, never mind.

Yes the Amokka looks sweet in it's molded slipperyness.

I fly heavy to penetrate............and for the landings. Heavy landings are the best. Scale builder/pilots take pride in replication of full sized performace and grace in the air but often fall short when the landing skids to a stop in 5 feet. I'm not likely to get a long skid out of the Hyper Hatchet, but I will try.

Flew yesterday and I'm not ready to trim the hatchet just yet.

Lesson 47B relearned once again yesterday.
"The lead and the battery must be securely secured in the plane...........for security."
The 10.8 oz of nose lead shifted during a hard launch, which made for an interesting short flight. Hint: It didn't shift forward.
As of 8pm last night, nose lead epoxied into the nose, battery and small trim lead bolted to the plane via a FRP tray and a steel bolt.

Poor Peter must green with envy at the sight of my fine lay up work.
Hyper Hatchet - battery (0 min 19 sec)
Jun 01, 2019, 11:38 AM
Everything's A Composite
Knoll53's Avatar
Thread OP
Some finishing details to keep the sand out. Fairings and fillets at the wing/fuse joint.
Final trim ballast has a new slightly aft setting. Now CG is adjusted by bolting the battery at different positions.

Sprayed clear coat on the black central wing panel and it looked great, when wet. Cured with quite a blush. That's what 400 grit sandpaper is for.
Jun 02, 2019, 06:37 AM
Registered User
EdSoars's Avatar
Hyper is looking slicker. One thing you might try in order to exclude sand from the moving bits is to cover the servo bays...

Y'know, I enjoy following the threads describing the builds that take manymanymany hours of exacting work and ingenious techniques, but I know I will never build anything like the RES Dart or Miniphase's big chevrons or Peter's Amokka, inspiring as they are. (There may be a causal link to their long winters and rainy weather! ) I also noted the green grass under their landing zones...

But I get the most practical benefit from your builds, which get new gliders airborne quickly, inexpensively, and effectively.

So keep up the good work!
Jun 02, 2019, 10:13 AM
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Knoll53's Avatar
Thread OP

I hate sand


Yes I admire the scale builders who spend seemingly decades building giant works of art, only to fly them 3 times. Choose your poison I guess. I hope to fly the pants off of this one. On the building board now.

Quick inexpensive effective would be nice. Rapid prototyping is the goal. I do love the process, especially when things keep moving. In real life, I design/draw buildings which literally take years, thanks to Communistic levels of government regulation.

Still have a list of finishing details, such as servo covers. I am pretty sure the dark blue fuse will be black soon.

The sand rains down from above, so the bottom of the wing stays clean. On day one, after a couple of flights, the entire nose was full of sand. Holes on top are a problem. It makes CG testing a guessing game. Only now, that I am relatively sand proof can I start zeroing in on the CG. Planks are all about CG. The top hatch still has a gap larger than a grain of sand, so that remains a problem. Possibly I can learn to land without kicking up sand.

It took me years to get used to flying in sand.



No sand landing.
Landing 101 (0 min 6 sec)
Last edited by Knoll53; Jun 02, 2019 at 10:33 AM.
Jun 02, 2019, 08:51 PM
Everything's A Composite
Knoll53's Avatar
Thread OP
Even in light lift, this plane moves. Kinda reduces landing options. Flying a heavy plane in light lift always freaks me out a bit.

Hyper Hatchet - A few landings (4 min 11 sec)


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