50% Zagnutz build - Here's hoping! - RC Groups
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Oct 16, 2003, 10:48 PM
Blue Foam & a Happy Home
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50% Zagnutz build - Here's hoping!

I've got a Zagi and a Pocket Combat Wing (PCW) and now it's time for my first scratch build. I'm armed with info from http://home1.gte.net/texhills/index.html and inspired by the vidoes from http://www.fdisk.com/rcaddict/ (see MZN50+1) I'm off.

First shot - just after folding
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Oct 16, 2003, 10:49 PM
Blue Foam & a Happy Home
bradm's Avatar
Next, setting up the layout. I had planned to use the 1020 Kokum in the photo, but ended up using a 950 Li-Ion to move the weight toward the nose.
Oct 16, 2003, 10:52 PM
Blue Foam & a Happy Home
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From here I stripped the skin from the insides of the wing trailing edge and glued with Super 77. The Elmer's in the photos was used as a weight rather than glue.

I was dissappointed in the large gap, but decided it provided good access to the equipment and should be much stronger after taping and covering.
Oct 16, 2003, 10:53 PM
Blue Foam & a Happy Home
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After the glue had dried over night I filled part of the gap with a foam piece cut to fit. I used 5 min epoxy and then ran clear packing tape across to hold it tight. A few more strips of tape across at angles really stiffen this baby up!
Last edited by bradm; Oct 16, 2003 at 11:01 PM.
Oct 16, 2003, 10:55 PM
Blue Foam & a Happy Home
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Since this is my first scratch build, it may as well be my first covering experience. I used Monokote from my LHS. Ironing it on is really kind of fun. It was different than taping my PCW, but about the same amount of work. It's definately cleaner.
Oct 16, 2003, 10:57 PM
Blue Foam & a Happy Home
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I used taped over FFF for the elevons as well. This is probably a bad idea, but I did it anyway. I covered the top in black so I'll have a real nice Halloween flyer!

Do you think it's over propped?
Last edited by bradm; Oct 16, 2003 at 11:14 PM.
Oct 16, 2003, 10:59 PM
Blue Foam & a Happy Home
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Here's the final product next to my PCW for size comparison. Don't worry the PCW is still holding up. I took it apart for retaping and I've robbed the parts from it for now. I'll get back to it, though as I really like it.

Thanks to CenTexFlyer for providing the info and to FDisk for providing the inspiration.

So, do you want to know if it will fly?

Me too!
Oct 17, 2003, 09:42 AM
Rip-N-Burn's Avatar
Nice build thread. what's the weight?

Looking forward to a flight report..

Oct 17, 2003, 09:50 AM
Registered User
I'm planing to do something quite close, but slightly ( perhaps the H is not at the right place ) different, i'm very interressed in your flight tests result.
By experience be very carefull with the CoG on such a small flying wing.
Oct 17, 2003, 10:51 AM
Arizona Rim Country

A true e-zoner !

Definately a worthy project ! Well Done. Somewhere I've got directions on how to overcome that gap on top. I'll see if I can dig them up.
Oct 17, 2003, 12:03 PM
Registered User
Great job, Brad!

I would imagine that guy will be a handful! As NoRudder said, check and then DOUBLE check that CofG. I would go for a tad nose heavy on the test glides with some up reflex to make sure. I bet you have yourself a real zippy MZN50 there!

And how much did you have in material costs???


P.S. I forgot to ask, I'm re-doing the website. What do you think?
Oct 17, 2003, 01:14 PM
Blue Foam & a Happy Home
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I have no clue on the AUW. It's the same equipment as I had on the PCW (including the Li-Ion for a while) so should be within a good range.

The C of G is about **EDIT 4.5 inches ** back from the nose as recomended by fdisk's site. I'm definately interested in getting that gap out of there on the next one I build, but it is really stiff with that little bridge and the tape.

It'll be a handfull to be sure. I wouldn't have tried it without progressing from the Zagi to the PCW. Just jumping right in on a little one like this could lead to frustration! I'm figuring this will be the bird I use to learn how to build. I'll fly it and thrash it 'till it's done. If I really like it I'll build another or, if not, happily go back to the PCW. I'm also interested in another variation called the Jackknife.

CTF - The new web page is looking great! It's interesting to see the twin version. If you have pics of your other variations we'd all be interested in seeing those as well. I've printed off your tips page. I wish I'd known before about not spreading hot glue with my finger

The weekend is shaping up to be a good one so hopefully I'll have a flight report soon.

EDIT: Almost forgot - I'm guessing about 35 cents for the foam, control link and home made horns (craft stick). I'm sure the covering was more, but I like the way it looks.
Last edited by bradm; Oct 17, 2003 at 02:38 PM.
Oct 17, 2003, 04:08 PM
Registered User

Re: That ugly little gap

Hey Fdisk,

I thought we came up with the geometry to cut section so that the gap was closed up!?!?! Am I dreaming, or was this something on my long and lovely "to do" list? The little man running around in my head pulling files found something that said essentially to just trace the intended airfoil on onto the center section cut on both sides....?? Does this sound right?

Last edited by CenTexFlyer; Oct 17, 2003 at 04:10 PM.
Oct 17, 2003, 07:32 PM
Blue Foam & a Happy Home
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Well, it's a pretty poor time to test out a new and small airplane. The winds are right around 15. I'm sure it's best to wait for another time.

So, I did it anyway

It started with a test "glide" across the back yard. I gave it a burst of throttle just to make sure it was steady. Very nice level straight ahead flight. My back yard is sheltered from the wind by trees and bushes. This was a pleasant surprise because I had just eyeballed the elevon settings.

Next flight was up the hill from my house in the baseball outfield. I used the exact same settings as I had for my PCW. Well, it flies. It doesn't fly well yet, but it does fly.

In spite of having the heavier Li-Ion up front it is a bit tail heavy I believe. Going into the wind it looks a bit like it's riding a wheelie - nose up slightly to keep it level. When the wind gets under it, up it goes. I can raise the nose higher and almost park it there facing into the wind. It was really difficult trying to gain altitude.

Turning down wind it speeds up in a hurry, but holds altitude. The really rough part is turning back into the wind. It slows way down when it's side is turned toward the wind and I have to be very careful in the turn not to tip it. It also gives back all the altitide it had gained going up wind.

Does this sound tail heavy or should I just consider myself lucky flying on such a breezy day?

I brought it back home nearly as pretty as when I left. (The airplane I mean. I'm not pretty)

Next I'm going to try moving the CG forward a bit at a time by taping a couple of quarters to the nose. There's also a little more room to slide the battery forward. Hopefully tomorrow will be a better day for this.

I'll let you know how it goes.
Last edited by bradm; Oct 17, 2003 at 07:34 PM.
Oct 17, 2003, 08:47 PM
Registered User
WOOF! Wind and a small plane are really hard to decipher. You really need a still, quiet day to just to experiment with both the reflex required and getting the CG right. I have been amazed at how a full sized ZagNutz will react to a breezy day as versus a still day - the difference can be quite dramatic. I would say that at this point you *MAY* be a tad tail heavy but explore that little extra space you say you have to move the batt forward. Then try it on a still day. I know I don't need to remind you since you've flown a wing before, but I'm going to anyway.... you need to let the wing "fly" and get up on "step" before you really start to see its' FLYING characteristics rather than its' power on nose, high "guiding" characteristics. If you managed to fly a circuit or two in this configuration, then I'd say you have yourself a diamond in the rough, and it only needs to be tweaked a bit to be a full on, rip 'em up flyer!


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