DTF Vought XF5U "Flying Flapjack" - Page 2 - RC Groups
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Dec 28, 2017, 10:11 AM
Registered User
Amazing job!
Vill be fun to follow.

// Mats W
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Dec 28, 2017, 12:44 PM
Registered User
aymodeler's Avatar
Really great build thread and exceptional workmanship!

I would love to build one of these myself, are you going to post plans?
Dec 28, 2017, 12:53 PM
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localfiend's Avatar
Quote:
Originally Posted by aymodeler
Really great build thread and exceptional workmanship!

I would love to build one of these myself, are you going to post plans?
Yup, plans will be posted. Dan Sponholz, the guy who makes the plans templates for Flitetest is helping me out with this project. He's making some of the more complicated 3D printable parts, and will be cleaning up the plans for me as soon as I make sure that everything fits perfectly. If we make the deadline, they'll be out by the 31st of this month.
Dec 28, 2017, 01:13 PM
Scratch Builder/Designer
SP0NZ's Avatar
Yup, plans will be coming. In the meantime, here are a couple of the 3D parts that I've modeled for it...
Dec 28, 2017, 03:31 PM
A Day @ a Time - Matt. 6:25-34
ruff1's Avatar
Nice one! Will it behave like a Nutball with twin props?
Dec 28, 2017, 05:03 PM
Kimbers Keeper.
BHOFM's Avatar
I'm not even going to post pictures of my stuff anymore, it doesn't hold a light to this project.

B
Dec 28, 2017, 05:47 PM
Registered User
localfiend's Avatar
Quote:
Originally Posted by ruff1
Nice one! Will it behave like a Nutball with twin props?
It would be really cool if it does. Outlook is promising.

The military RC version they built first seems to have nutball like behavior.

Vought V-173 Flying Pancake (3 min 1 sec)


Quote:
Originally Posted by BHOFM
I'm not even going to post pictures of my stuff anymore, it doesn't hold a light to this project.

B
Nah man, I'm trying to inspire, not discourage.

I used a paper card model as my baseline, then lots of trial and error making shape changes to account for the way foam bends instead of paper. CNC machine helps for prototyping as well. Took me 8 planes worth of parts, and lots of one offs of weird stuff to get this thing the way it is.


Final rendition is pretty much done. Just got to wait for motor mounts to finish printing. And figure out what kind of landing gear I'm going to need. Not sure if the snow is staying.



Dec 28, 2017, 06:18 PM
Kimbers Keeper.
BHOFM's Avatar
I would be very interested in a kit?

What are the dimensions?

BTW, I design, build and fly some pretty strange stuff!



40incho fungle (5 min 40 sec)
Last edited by BHOFM; Dec 28, 2017 at 06:27 PM.
Dec 28, 2017, 06:39 PM
Registered User
localfiend's Avatar
Quote:
Originally Posted by BHOFM
I would be very interested in a kit?

What are the dimensions?

BTW, I design, build and fly some pretty strange stuff!

Dunno if I can make time for cutting kits. I'm a farmer by trade, this is a hobby and I've got a backload of stuff to cut for people. Might consider it a bit further down the road.

Plane is like 25" wide for the main wing/body. Tail to tail it's more like 34.5"

Wing area if you count the tail is 540 square inches. Weight is about 775 grams without battery. Say around 1000 grams all ready to go. Maybe a tad more depending on weight of landing gear or skis.

So, wing loading of 9.41 oz. / sq. ft. or a WCL of 4.9 Not as light as your holey nutball, but still pretty darned good for a scale warbird.
Dec 28, 2017, 07:03 PM
A Day @ a Time - Matt. 6:25-34
ruff1's Avatar
With that WCL, find the buzzards and join them in the thermal! So cool.
Dec 28, 2017, 07:05 PM
Kimbers Keeper.
BHOFM's Avatar
The proper name is an O-fungle. It is hard to figure the wing loading, we have done lots of tests
with and without the hole and the only thing we have found is the with hole handles wind better.

The loading on the military one is about 5oz per sq ft. If you don't discount the hole,it's about 4.

The wind during the flight in the video was over 20mph at times, if you look at the last landing
the plane is going sideways just about the same speed it is going forward.

I am in no hurry about a kit, keep me posted.
Dec 28, 2017, 09:03 PM
Ken's CAD Models
dz1sfb's Avatar
Quote:
Originally Posted by localfiend
Nah man, I'm trying to inspire, not discourage.
Doing a fine job of it! The one thing I've found discouraging about the paper covered foamboard was the exposed edges that tend to get ratty with time. You've completely done away with the issue. More builds like this are really uplevel!

Ken
Latest blog entry: Mini H Quad Project
Dec 29, 2017, 04:45 PM
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localfiend's Avatar
Quote:
Originally Posted by dz1sfb
Doing a fine job of it! The one thing I've found discouraging about the paper covered foamboard was the exposed edges that tend to get ratty with time. You've completely done away with the issue. More builds like this are really uplevel!

Ken
I've got a few more like this in mind. It's a lot of fun when they come out looking good. Now I just need this second version to fly well too.

I'm all ready to go, but it's raining....
Dec 29, 2017, 09:48 PM
Registered User
localfiend's Avatar
XF5U Version 2 Maiden 12.29.17 (5 min 35 sec)



And kersplat again lol. Got one flight and landing, and then another flight with more of a crash into a bunch trees instead of landing.

Think I was pushing the CG back too far trying to gain elevator authority. Flew fine until I touched the rudder and the plane went nuts. Big time yaw instability with differential thrust input.

I'm repairing the damage, adding slightly bigger rudders and adjusting control surfaces instead of pushing CG back further. Both the V-173 and XF5U had full flying tailevator thingies. On mine, the outer surfaces were only ailerons. I'm going to make them act like elevons and see if that's enough.

If not, I'll increase the outer control surface size. And if that doesn't do it, I guess I'll be going with full flying surfaces. Shouldn't be too hard to do, they're already separate pieces after all.
Dec 30, 2017, 03:27 AM
Registered User
JabiruAbe's Avatar
Again I love the looks of this. I probably missed it, but its just props and not edf's, yes? (Userofmuchtape@glue on FT)


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