BajiWing: Flying Wing using "Armin Wing" technique - Page 3 - RC Groups
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Mar 26, 2012, 06:05 PM
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templton89's Avatar
that's awesome, I definitely would like to see how that turns out! And don't worry about it being thick, look at zephyr II, it looks like it's about to give birth, but it's a fine wing.
I wish I could score some black foamboard, to create some diversity in my builds.

As I mentioned earlier I modified the canopy a little, it is now lower, and the battery sits along the root cord, not parallel to it. Also added velcro instead of using tape.

I should be getting my new motor sometime this week. For comparison I get about 150watt per pound of weight, with new setup, I should get ~300-400 watt per pound, and with a smaller prop it should go pretty fast.
I might have to use a longer motor mount, to secure it better to the plane, and add some weight to the front to compensate for heavier motor.
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Mar 27, 2012, 12:50 AM
Assault the sky
secretspy711's Avatar
Here's my progress so far. After some more thought, I am definitely going to add the center section -- I am tired of having to cram wires in spaces that are too small, especially if I FPV it. The center section will allow me to have a nice big hatch, just like a Zephyr.

don't mind the mess :-P
Mar 27, 2012, 12:25 PM
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templton89's Avatar
cool, keep it going

I've had some ideas about mid section that I still haven't perfected, but maybe they'll help you come up with something. First one was for modular 40" plane that comes apart.

this was first prototype of bajiwing, it flew, flew rather well, but it was pretty ugly and unfinished

Mar 27, 2012, 02:09 PM
Ed @ Experimental Airlines
ExperimentalAir's Avatar
That green/gray one is my favorite so far. If we can integrate a carbon arrow spar into a tube fuselage design which can still be disassembled I think that would be a real winner.
Mar 27, 2012, 02:12 PM
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templton89's Avatar
Originally Posted by ExperimentalAir
That green/gray one is my favorite so far. If we can integrate a carbon arrow spar into a tube fuselage design which can still be disassembled I think that would be a real winner.
that's pretty much my goal for 2012 as far as RC
Mar 27, 2012, 03:08 PM
Ichy to Build and Fly.
rnmosaic's Avatar
Originally Posted by templton89
that's pretty much my goal for 2012 as far as RC
Hi Ed and Templton,

You guys are extremely BAD !!!

Unreal - Now I have to go and get more $tree foam and start experimenting with this new idea...

You guys are Amazing !!

Thank you so much for helping newbies like me ...

Keep the ideas coming in ...

This time I will post the pictures of the build of the wing with Tube fuse ...

Super -

Thank you
Mar 27, 2012, 10:41 PM
Assault the sky
secretspy711's Avatar
Very cool Templton! I had imagined an airfoil-shaped center section, but now you have me thinking some more... the tube fuse is just so simple and elegant.

Did you FPV your original? I'm just thinking mine will have to carry some extra gear, so I might want the extra lift of a center airfoil. Any idea what your watts/lb was? Wing loading?
Mar 27, 2012, 11:13 PM
IFO's are planes too
atone1's Avatar
I've been flying a similar design of this type of wing for over 2yrs.
Here's some things that might help you guys out.
I use this site for airfoil pattern templets; the NACA ones that have symmetrical cambers are good for level and inverted flight.
The NACA 0010-34 is what's on most of my wings. Here's how to use this site.
Click an airfoil name to see it displayed. Once there click on the picture of the airfoil to go to it's plotting page. Under the display area you can change the size and other perimeters of that particular airfoil. To size it just change the inch # from 3 to 14 and hit enter.
Here's how I build the inside of my wings. The space between the ribs is for the battery and I cut holes in the side of the ribs to run wires for flight gear.

On the break down wing project: why couldn't you make it like the balsa planes?
A 3 piece unit where the wing panels have a plywood rib with a hole for the spars that's sleeved with a fiberglass and epoxy tube glued to the inside of the panels. Thumb screws hold the wings to the wing panels. Blind nuts on the back of the plywood ribs and the main stress is on the tubes and spar assembly. The ends of the tubes would need stops on them so the spars can't slide and allow the panels to flap at high speeds. The fuselage section could be used as a modular unit so other size wing panels could be added on later. This would be a great test bed for trying out other wing airfoil types without having to build the center section. Lots of R&D will need to be done on this as you figure out if it will work with one spar or two. One spar might work on the 40" version with pegs and alinement holes in the plywood ribs. I think this breakdown modular wing system is more suited for wing sizes over 48" as that's when they get hard to transport and the added weight will come into play. A heavy wing is not fun to fly, IMO. Fiberglass practice arrows from any sporting goods store could be used as spars.
Have you notice how they act as gliders if you keep the weight down and C/g balance right? I gain more flying time by shutting off the throttle and playing around with the thermals.
Well, that's some of my thoughts on these wings.

I built this PVC launcher to sling these wings into action just by pulling a string.
Mar 27, 2012, 11:55 PM
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templton89's Avatar
I just assembled my fpv gear tonight so no I bought a kit from HK , and it's messed up, they're sending out 5v cameras and direct you to use them with 3s 11.1 (12v) lipo... naturally everyone burns their camera on first try, as did I, without even knowing it. But I did some soldering and hooked up my gopro to video tX so I'm good to go from now on.

That modular plane did carry a goPro. Not sure about watts, but it's pretty low at the moment. I'd say around 300-400watt total, so 150-200watt/lbs .
It's a Turnigy D2836/8 1100KV motor, on 3s with 9x5 gws prop. My current Bajiwing is ~800g and it's pretty snappy, not rocket fast, but it's not struggling by any means. I put go pro on it , without case, and took it pretty high , even with strong winds.
I just received a watt meter tonight, so I'll give you more info on that later
I will try 8x6 on this plane, just to see how it does.

However I'm planing to put a NTM Prop Drive 28-36 2700KV / 595W on it as soon as I get it, with 6x4 prop to test for max speed.
I will also make another wing, using same design, strictly for FPV, using NTM Prop Drive Series 35-36A 1800Kv / 875w with 8x4 prop on it. If I keep it withing 1kg (~2lbs) that would be ~400watt/lbs, but that number would probably go down, because I will have to use multiple lipos to feed this beast of a motor, and will suffer from some extra weight.

I've considered most of these ideas. I already have some carbon arrows and ideas for new modular plane. I'm even thinking about making a wing same way as I do now, then slice it into 3-4 pieces and trace the profile of the cut to create a rib templates for future builds.

I have a few sheets of Coroplast laying around, so I think a few coroplast ribs + pink foam strip that I'm using now and tunnels for carbon rods will make a strong and light enough joint system. Also as you may have noticed on my current wing carbon rods don't even stretch all the way to the tips. Ed's Armin airfoil + pink foam make it rigid enough to fly even without carbon rods, but I added them for security, because I like to show off and crash now and then
My biggest problem right now is finding some aluminum tubes of right diameter so I could couple carbon rods using those. I want to drill holes on tips of both carbon arrows and aluminum tubes, so could slide arrow in tube, put a pin, and secure it in there.
Mar 28, 2012, 02:42 AM
Assault the sky
secretspy711's Avatar
Sucks about the camera, but I'm glad you got it working.

On a related note, I did a FPV Stryker with a 2836 3200kv motor, 6x4 prop. It will do 90mph straight and level, and well over 100 coming out of a dive. That's with a circular antenna on each wingtip causing all sorts of drag. Burned out a 40A ESC on the first flight. It's somewhere in the neighborhood of 650 watts! That thing is a foam-bullet and glides like a rock because it's heavy. I also use a bungee launcher for it because it's a PITA to hand launch.

I am really impressed with some of the Zephyr's flight times, so I'm aiming more for duration on this Armin wing. I decided to go with an 8" white airfoil center section. I used an aluminum arrow shaft for a front spar and a wood dowel for the rear. So there are 2 rods going through it but still plenty of space for components. It can fit a couple of 3S 2200's inside if it will carry the weight.

Are you on FPVlab? Lots of good stuff over there, including Ed.
Mar 28, 2012, 11:05 AM
Ed @ Experimental Airlines
ExperimentalAir's Avatar
secretspy711 - That's a slick wing. Can I request some pix of the open center section to look at the spar arrangement? Also since you have aluminum arrow shaft experience, any chance you could caliper the internal diameter of what you have in consideration of finding carbon arrow shaft joiners?
Mar 28, 2012, 12:40 PM
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secretspy711's Avatar
Hi Ed-- sure, I will do that when I get home tonight. I need to figure out how big of a hatch I want because it's all closed up right now.
Mar 28, 2012, 12:55 PM
Registered User
templton89's Avatar
Originally Posted by secretspy711
Hi Ed-- sure, I will do that when I get home tonight. I need to figure out how big of a hatch I want because it's all closed up right now.
I would also suggest reinforcing areas around the hatch, maybe by creating some stands or ribs/walls around the perimeter of the opening. Taped up $tree foam can easily go from very rigid to soft in a matter of a few cuts
Mar 29, 2012, 01:26 AM
Assault the sky
secretspy711's Avatar
Aluminum arrow shaft dimensions:
ID: .297"
OD: .337"

I didn't have time to cut a hatch tonight, but here are some pictures I took before I joined it all up and closed it. I am only using the 2 horizontal spar locations. As you can see, I left a channel for one along the length of the wing but it wasn't necessary.

Airframe-only weight from the picture in my previous post is 370 grams, including the winglets which are not attached yet.

Another thing to note is the black foam board seems to be slightly more difficult to depaper cleanly, even though it is the same brand.

I estimate the AUW will end up around 2.66 lbs with all my FPV gear and two 3S 2200's. Wing area is 3.05 sq ft... a wing loading of .87 lb/ft^2. That's lower than a TBS Zephyr which is .91. Winglets also artificially "extend" the wing by about half their height.

Sorry for going from grams to lbs...

Good point on reinforcing the hatch, but I don't think it will need much -- the spars effectively take the center foam out of the bending load path.
Last edited by secretspy711; Mar 29, 2012 at 01:46 AM.
Mar 29, 2012, 09:07 AM
I used to like trees
rchank's Avatar
I have some old Micro-flite fiberglass arrows that I've had since I was in high school. I recently bought some carbon arrows and happy coincidence; the carbon arrows fit perfectly inside the old fiberglass arrows. I envision a wing center section with two pieces of the larger diameter arrow which receive the outer wing sections containing lengths of the smaller diameter arrow.

I'm looking forward to trying out this method, but I have so many build projects in the pipeline it may be awhile

I like the idea of a dedicated AV/FPV wing with the camera mounted in a custom made center section.

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