A6TEXAN

the download manual we are using doesnt address fiberglassing the center section, unless im just missing it. but "experienced" modlers will do this anyway. though im still skeptical of the very short dihedral brace and balsa root ribs, even with a 2 inch wide fiberglass strip.
i am going to increase the length of the dihedral brace thru W2 up the the edge of the landing gear block. this will make it 8.50 inches long. this will make me feel better. dont get me wrong im not knocking the design, but at a minimum i think W1 should maybe be cut from aircraft plywood and the knockout for the brace be lazer cut into them.
i kinda scratched my head when i initially saw the balsa W1 rib. ??but, oh well ??
now time to proceed with cutting ailerons..

A6TEXAN

HEADS UP for the fellas intending on using the online PDF instructions for building their kits: In step #34 on page #76, it tells you to drill a 1/4" hole thru the guide holes in F2A/WDD into the wings leading edge and into the "ply dowel doubler" inside the wing. this is the first mention of the "ply dowel doubler". i suppose this is to be glued inside the wing behind the balsa sub leading edge during wing construction. without this ply doubler the 1/4" dowels are just going into balsa wood only in the leading edge.
i will have to cut into the bottom sheeting and insert a fashioned "ply dowel doubler" as i cannot locate this part in the kit.
as some can probably tell I have not built a kit in some years, as i should have caught this missing part way back in the build. LOL.

Also go ahead and open the sealed plastic bag and remove the "ply wing bolt block" and measure it. if it is like mine at 3-3/8" long
go ahead and cut another one to fit at 3-3/4" long. if you have to cut another block, dont forget to cut the angle along one edge to fit against F3

A6TEXAN

i found a picture of the "ply dowel doubler" installed in the wing. as i figured it is to be installed behind the balsa sub leading edge.

NortheastAero

My Feedback: (6)

Just some thoughts:<o></o>

The wing that you found pictures of is a Mark-I wing. It has a different design than the Mark-II wing in your kits. The ply doubler behind the leading edge was edited out of the design/kit because we selected hard balsa for the LE. That's a lesson learned for me is that with these short kits Icannot rely on my selecting the propper hardness for the LE and not telling you about that. You can add it in if you like or if you are using softer balsa for the LE. Softer balsa is fine for the length of the wing LE, but don't go below medium hardness.

One of the differences in the wings is that the Mark-II airfoil is thinner than the Mark-I airfoil. The thinner airfoil gave a higher high speed range for the model while the specific airfoil gave a nice low-speed handling. The Mark-I wing used vertical grain balsa shear webs throughout the wing. The Mark-II replaces the balsa shear webs with a 1/16" aircraft ply shear web the length of the wing. When the dihedral brace is glued to the ply shear web you get a compound shear web that runs the length of the wing. It is lighter and strong than the other design. Now, if you really want to strengthen the dihedral joint you would need to add thickness to the dihedral brace not length.<o></o>

A local pilot once lost control of his Twin-Air .45 due to a bad on board battery pack. It was fully charged and he went up and 3 minutes later lost control of the airplane. Unfortunately the plane was inverted and heading toward the pit area. Nobody was hurt in the subsequent crash when the plane dove and impaled itself into a car tearing the metal on the car. Fortunately it was his car. The wing was salvageable after the crash. It's a tough wing. I've never seen or heard of one failing in flight. But like most things, it depends on the builder.

As for fiberglassing: 2-3 layers of 3/4-oz cloth for 2-3 inches to each side of the joint will alleviate most people's concerns. I would suggest running the cloth at a 45-degree bias. Other places people have suggested glass cloth is on the insides of the nacelle sides where it meets the wing and around the fuse in front of the leading edge of the vertical and horizontal stabs (Just be careful not to add too much weight back there). If you want to go high-tech, use a piece of CF cloth or Kevlar around the LE of the wing at the center section before drilling and installing the dowels. This will give you more strength that the extra plywood behind the LE.The stress you are concerned about here occurs in negative-G maneuvers (outside loops and snap-rolls).

As for the "ply wing bolt block", you know, I was cutting that part all day long and it's still too short. All I can do is apologize for missing the mis-cut part. Sorry guys.

Take care,
John<o></o>

A6TEXAN

That all seems resonable to me John. after thinking about the aircraft ply shear web design of the Mark II, i saw the big picture. thanks for addressing these concerns. also thanks for the input concerning strengthening the nacelles. no big deal on the wing bolt block.
Now back to more building.

panhandler

Bump

Curious to see how the builds are going and what type of scheme anyone used.

9ballvalk

My Feedback: (13)

Are there any of these kits left? Does anyone have one they would like to sell. Please PM me if you can help.

9ballvalk

My Feedback: (13)

Any chance of running another batch of the twin-air .45, Train-Air .60, or Sport -Air .60 kits.

Please consider as I'm in for a few of each....

Thanks,

John

rcperspectives

Hello, Is it possible to get a short kit for the NE Aerodynamics Twin Air .20 and or .45. If no kits. How about plans and instructions. I wore out three O.S. .40s and a few sets of wheels on my old twin air.

SRQFlyer

My Feedback: (17)

Check your PM folder

paulrcpilot-RCU

My Feedback: (32)

I have a spare twin air 40 kit if you are interested, I bought two when they were last for sale completed one, I will not build the second one. Paul