Author Topic: Something a little different (added: flight report).. (Read 2123 times)

minnesotamodeler · « **on:** May 04, 2009, 03:09:43 PM »

Here's what's been occupying my time and keeping me out of trouble lately. A rather large--but light--stunter using a Norvel .061; call it "3/4A".

The "different" aspect: Using that Droopy Diamond airfoil I first tried on a couple of combat wings, where it performed spectacularly...I wanted to see how it would do at slower PA speeds. The principle, remember, is to use diamond-shaped extra-tall ribs widely spaced with no surface spars, and let the covering droop between them, assuming a more typical curved airfoil. The airfoil varies from about 25% at the ribs to around 14% at lowest point between. The last picture shows the droop of the covering.

Span = 34", area 250 sq. in., weight RTF a skosh over 10 oz. Floppy balloon tank inside the cheek. At least 42' lines to start out, I'll probably end up using longer. Check it out.

afml · « **Reply #1 on:** May 04, 2009, 05:51:51 PM »

WOW! Great job Ray!

Where did the end of the main spar go??

Expect a full flight report.
Great looking plane! Well done!

"Tight lines!"

Wes

Robert McHam · « **Reply #2 on:** May 04, 2009, 06:40:03 PM »

I like it!

I look forward to your maiden report.

Robert

minnesotamodeler · « **Reply #3 on:** May 04, 2009, 07:58:05 PM »

Quote from: afml on May 04, 2009, 05:51:51 PM

WOW! Great job Ray!

Where did the end of the main spar go??

Expect a full flight report.
Great looking plane! Well done!

"Tight lines!"

Wes

HMMMMM, I thought I answered this post...the interior spar ends at the first rib in from the tip, a kind of philosophical wave at weight savings. All the stress is at the root of the wing, not the tip...no need for reinforcement there.

Fer shur, there will be a full flight report whenever it happens.

Larry Renger · « **Reply #4 on:** May 04, 2009, 10:41:11 PM »

Way cool, MM! The size is right, the power perfect, I'll bet you end up between 46 and 48 ft lines. Keep up the good work!

minnesotamodeler · « **Reply #5 on:** May 05, 2009, 12:56:52 AM »

Thanks Larry, I suspect you're right--I use 48' with my LittleAxe.

John Crocker · « **Reply #6 on:** May 05, 2009, 01:27:25 PM »

I WANT ONE! That is a cool plane Ray!

minnesotamodeler · « **Reply #7 on:** May 05, 2009, 03:50:09 PM »

Now don't start hollering "kit it!" until I have at least flown it...

john e. holliday · « **Reply #8 on:** May 05, 2009, 04:22:20 PM »

Front view sure looks strange. The other pictures look great. Spring time should be in your by the end of the month. Let us know how it flies. DOC Holliday

minnesotamodeler · « **Reply #9 on:** May 05, 2009, 08:46:28 PM »

Front view is a little controversial; something I've wanted to try for awhile, now that I've tried it I'll probably put it to rest. Didn't come out quite as I envisioned it.

"Strange"...I appreciate your tact.

Robert McHam · « **Reply #10 on:** May 05, 2009, 10:42:22 PM »

It is a little 'strange' but I have envisioned this more than once just to be different. Don't be surprised if I have some of mine have the same 'low profile' front end.

Robert

minnesotamodeler · « **Reply #11 on:** May 06, 2009, 09:17:37 AM »

Quote from: John Crocker on May 05, 2009, 01:27:25 PM

I WANT ONE! That is a cool plane Ray!

By the way, I neglected to give credit where credit is due...John is the gentleman who first utilized the "droopy diamond" airfoil concept. Show us your green machine, John.

John Crocker · « **Reply #12 on:** May 06, 2009, 05:54:11 PM »

Hey Ray,

Thanks for the props, but I must say your lines are a lot cleaner than mine. Here's the "Green Giant". Was one of the better planes I ever flew.

And my favorite plane ever with diamond wings, "The Confederate". Both of these planes were stolen and recovered in pieces. The confederate was powered by 2 .061 AP Wasps and was a joy to fly.

minnesotamodeler · « **Reply #13 on:** May 06, 2009, 08:17:45 PM »

You gotta build another Confederate, that's a cool plane.

John Crocker · « **Reply #14 on:** May 07, 2009, 04:43:56 AM »

I've thought about it, but I'm down to only one engine and money's tight right now. It was a fun plane to fly, it had the prettiest takeoffs and landings of any plane I ever built, guess I got the ballance just right on the trike gear. I think it had a 42" span and weighed in aaround 17 oz.

John Crocker · « **Reply #15 on:** May 22, 2009, 11:22:33 AM »

Flight report?

minnesotamodeler · « **Reply #16 on:** May 22, 2009, 02:56:52 PM »

Not yet, been too windy here, now that it's finally settling down I have honeydo's to do...

john e. holliday · « **Reply #17 on:** May 27, 2009, 05:07:14 PM »

you are supposed to do the honey do's when you can't fly. DOC Holliday

minnesotamodeler · « **Reply #18 on:** May 28, 2009, 05:52:57 AM »

Tell my wife, John...on second thought, let's not rock the boat.

Still haven't got out. Thought I would yesterday but the weather didn't cooperate, windy and cold and damp. High was 53 I think. And here it is nearly June! Maybe Saturday if it warms up and stays calm.

minnesotamodeler · « **Reply #19 on:** June 01, 2009, 02:00:55 PM »

FINALLY--FLIGHT REPORT!!!

Got the Droopy Diamond out today...must say, it exceeded my expectations. VERY stable, to the point I was concerned at takeoff, when it settled into a very deep groove, it must be noseheavy and unmaneuverable--but not so, turns extremely well and tight. That extreme stability enables really nice square corners, no overshooting, coming out of a wingover just square and back into that deep level groove. Makes even MY corners look good.

I used 48' lines, and will try 52' next time as it is too fast--under 3.5-sec. laps, on 48' lines that's over 60 mph. This is a big plane I thought, 34" span, 240 sq. in. wing, but I guess that droopy airfoil lends itself to lotsa speed. It's probably 10 mph faster than my LittleAxe--I flew them back-to-back for comparison. The LA still flies very well but I think I'm gonna prefer the Droopy Diamond stunter once I get the speed under control. (I'm using a 6x2 prop now, can't get lower pitch than that!) I may switch out the .061 for an .049 just to see how it works with the smaller engine.

All in all, I count it a huge success. couldn't be more pleased with it. Thanks for the innovative airfoil Mr. Crocker!

john e. holliday · « **Reply #20 on:** June 04, 2009, 10:17:01 AM »

Sounds great. DOC Holliday