RC Groups

RC Groups
    Hand Launch
        Build Log Neos

#1 ThomasLee Mar 04, 2012 10:04 AM

Neos
 
3 Attachment(s)
This plane has been in the making for a little while now, and I am about to start work on the last (I hope!) prototype before we go into production :)
The is trimmed, but the flaperons haven't been cut yet, maybe I'll have time to do that tomorrow.
Wing is ~22.1 dm^2 using the Zone V2 foils developed by Gerald and our own 3p planform.
The vertical uses the Z4D foil, and all surfaces are bagged kevlar.

The weight is 113 grams before cutting the flaperons, so maybe it will go down a little bit after that. The wing is not prefaced in the conventional sense, but is done so with tape, maybe I will get that part done on this wing to show you guys tomorrow or the day after :)

Neos comes with a 1-p carbon fuse and is designed to be rudderless, but there is more than enough room to fit 2 servos in the nose for a rudder.

I didn't have time to pick up the tails and control horns from my friend today, so I won't be able to show them to you guys until later :( I'll try to get them sooner!

Hope to have time to finish the 3-view drawings sometime this week or next week.



--------------------

Copy&Paste from post #81

Here's some of the measurements I promised. The build is very straight forward, very similar to other bagged wing kits, but I've also wrote some notes for reference during building. A lot of this is actually covered when I did my build.
I will try to get a proper instructions manual out as soon as I can after I arrive back in Hong Kong next month.
I'll post this into the first post as well for easier reference:

-Wing LE to H. Tail LE: 680mm
-Wing LE to V. Tail LE: 765mm
-Dist. Servo arm to wing root: 50mm
-CG: 65mm - 75mm
-Wing LE to forward bolt c/l: 35mm
-Wing LE to rearward bolt c/l: 120mm
-Wing dihedral: 5.7 degrees


-For V. Tail installation:
I like to cut the vertical itself to accept the boom. I also notch the end of the boom slightly so that it fits into the V. Tail and goes on either side of the front carbon spar. Glass the tails to boom connection with light glass. Also, please note, while the vertical planform is symmetrical, the airfoil is not. Install the vertical with the 'top' of the foil facing the launching blade.

-Blade installation:
Install the blade ~1cm in of the tips. The 3K carbon reinforcement should be enough for most pilots, but if you are an extra strong thrower, you may add some carbon tow around the joint and use epoxy to laminate it together.
Make sure the tip clears the web of your fingers for safety and to increase launch height.

-For H. Tail installation:
Mark the bolt locations and drill through the tail. Use a small piece of wire to scrap the foam out of the surrounding area, and then place a piece of tape on 1 side of the holes. Fill the void using a mixture of microballoons mixed with epoxy, and let cure. Redrill the holes, and you have made the hardpoints for the tail.
The tail is hinged at the top for easy spring installation. I like to use small lengths of toothpicks of aluminum tubes for the spring housing, which I glue in with epoxy. Use the in-line method of the spring to prevent surface warping. The middle section of the spring should be 25mm long.

-Wing bolt hole:
forward hole is just in front of the forward wing spar, and hardpoint should connect with the wing spar to increase strength.

-Servo installation in fuselage:
The fuselage can accept JR285 servos, and is the recommended servo for the tails (and wings, if you choose to put all servos in the pod.
It fits perfectly with the correct installation.

---------------------

My throws:

Speed: 0mm
Cruise: 2mm
Float: 5mm

Flaperons:
Up: 14mm
Down: 23mm

Flaps:
~50 degrees

Elevator:
Up: 12mm
Down: Touches boom

Snap Flaps:
Elevator down MAX: Flaperons up 4mm
Elevator up MAX: Flaperons down 2mm

CG:
70mm

---------------------

If I missed anything, please ask, and I will answer and update it into this list before I make the manual.


**IMPORTANT
Please use epoxy to build the Neos, as the foam has been found to be reactive to (some?) foam-safe CA's. If you must use foam-safe CA, please make sure to test it on a piece of foam cut out from the servo bay prior to using it on the actual build.

#2 robert14 Mar 04, 2012 10:08 AM

Looks really nice. You used carbon strips as spars? If so, why did you put them in like this. I've made 2 zone wings, one with the spars in like you did (with carbon dbox) and one with the spars in just flat under the wing skin. The one with the flat spars didn't have a carbon dbox and is stronger in bending ;)

Don't worry, it will work. It's just not as strong. (less work to put them in like this though :))

#3 ThomasLee Mar 04, 2012 10:10 AM

Hey Robert, thanks!
We are using carbon rods as the spar instead of tape because we found it to be stiffer and more aesthetically pleasing :)

#4 robert14 Mar 04, 2012 11:31 AM

with flat i also meant carbon rods. I use 3x0.8mm carbon strips.

watching your pictures I thought you were using this layup:
http://desmond.imageshack.us/Himg221...png&res=medium

I used this layup on a disser wing:
http://desmond.imageshack.us/Himg21/...png&res=medium

and that layup (using thesame carbon strips) is stronger in bending then the layup you used

#5 G_T Mar 04, 2012 11:49 AM

Actually, it is stiffer in bending. Stronger is harder to judge. Flat carbon strips tend to fail in buckling due to insufficient support by the foam and the skins.

Round or rectangular rods, particularly the IM ones IMO, are quite a bit stronger in practice than ribbon spars. That is fairly obvious to anyone who has a midair with each. The difference is such a spar, even without the wing, has a fair bit of buckling resistance of its own.

The 0.8mm thick rods might have enough thickness to be distributing a load some instead of buckling. I have not used them and I do not know. Thinner is often done and that fails easily by buckling.

Gerald

#6 Airbud Mar 04, 2012 06:57 PM

Congrats Thomas.
I still look at the first wing you started designing and put in DropBox.
Let us know how it flies.
Wayne

#7 ThomasLee Mar 04, 2012 09:48 PM

Robert,
As Gerald said, we found that method tended to buckle easily, while the rods are stiffer and less likely to buckle. We are using 1.5mm CF rods for the spars.

Wayne,
Thanks! It is a very good flier, I will post the data on this one when I start flying it sometime next week. Are you guys still going ahead with the project?

Thomas

#8 ThomasLee Mar 04, 2012 10:10 PM

1 Attachment(s)
another photo post-trimming. planes come with flaps cut and ready to go, I just couldn't wait any longer until I posted pics and showed these wings to you guys

That is 3K cloth on the tips, plenty strong for even monster launchers

#9 Wave Glider Mar 05, 2012 07:40 AM

Nice work Thomas!

#10 tasbori Mar 05, 2012 09:21 AM

Thomas, the finishing looks very good. looking forward to some flight reports after prototype is completed.

#11 ThomasLee Mar 05, 2012 07:35 PM

Thanks Kyle, I'll pat the team on the back :)
Thank you Kelly, I'm quite pleased with the finishing too, and we have some new bagging equipment arriving so it should help us pull a bit more pressure. I know how it flies already, but I'll save it for later after I finish up this newest Neos :D

#12 ThomasLee Mar 06, 2012 06:31 AM

1 Attachment(s)
Starting work on the servo holes. Just mark the position of the servo, slice off the top layer of skin with a blade, and route out the foam at the correct depth.

The Neos is originally planned to have the outboard edge of the servo 10cm from the root, but on this one we are trying to see if we can place it at 8cm while still maintaining the aileron stiffness. If it works, then we will be able to improve the plane sensitivity even more.

#13 ThomasLee Mar 06, 2012 10:26 PM

2 Attachment(s)
Milled the servo hole and tunnel for the wires. Milled out some foam for the wire to bend into the tunnel too.

Next time I will try to cut the skin with 1/8" oversize of the servo hole, so that there will be a seat to tape the skin back on after the servo installation. Wish I thought of that a couple hours earlier so I could try it on this wing!

#14 samc99us Mar 06, 2012 11:04 PM

Tough to cut the skin in such a manner I think Thomas. Are you using a CNC mill to do the dirty work or a normal Dremel routing bit?

Wings look great BTW, wider at the tips than some of the Zone v2's I've seen which is good!

#15 ThomasLee Mar 06, 2012 11:30 PM

Thanks Sam, I wanted the Neos to be quite well-mannered, and to increase sensitivity to thermals. It helps to keep the tips stronger too, which is a nice bonus.
I think it wouldn't be too hard, I can cutting the skins with 2 or 3 passes on a new blade, and it wouldn't disturb the foam underneath I believe. The holes and tunnel is just using a Dremel, the height guide, and a ruler. I'm tempted to mill the holes with CNC when milling the cores in the future, but I haven't been able to figure out how to keep the shape without the foam underneath either with or without a mould (since we will not be vacuuming the skin to the mould first, if we do use a mould).


All times are GMT -5. The time now is 09:10 PM.