Short Sagitta 900 wing rod?

[2motheus]

I just acquired a nice Sagitta 900 airframe. The plane has never been flown, and I don't have the plans, so I'm coming here to resolve a question that concerns me.

My question is, "How far into the wing root should main rod go?" The tube in this plane is only about 2 1/2 inches into the wing and seems too short to me. The fully sheeted part of the wing is at least 6 inches on each side and it just seems like the wing rod should "use" more of this reinforced area of the spar.

Could someone in the know tell me if what I have is OK, or is some surgery required before I fly.

Thanks,
Tim

[StevenatorLTFO]

That seems very short, I'd be skeptical of that. If you don't have an answer before I get home tonight, I'll dig out my plans and see what they show.

Steve

[LSF2298]

I just measured one I have in a kit and it is just over 5" long. Given the width of the fuse, it does seem short.

[Stan_in_AR]

I just acquired a nice Sagitta 900 airframe. The plane has never been flown, and I don't have the plans, so I'm coming here to resolve a question that concerns me.

My question is, "How far into the wing root should main rod go?" The tube in this plane is only about 2 1/2 inches into the wing and seems too short to me. The fully sheeted part of the wing is at least 6 inches on each side and it just seems like the wing rod should "use" more of this reinforced area of the spar.

Could someone in the know tell me if what I have is OK, or is some surgery required before I fly.

Thanks,
Tim

There was some issue years ago about the pine block in the wing splitting and some guys laminated a piece of ply to the pine block. If the wing was built per plans you won't have any trouble unless you try to gorilla launch it.

Stan

[2motheus]

I just measured one I have in a kit and it is just over 5" long. Given the width of the fuse, it does seem short.

The entire rod is only 5 inches long?! If that's so, then I should be all set. I don't plan to launch it hard.

Thanks for the replies.
Tim

[LSF2298]

I found my list of materials and it lists the Wing Rod at 5/16" by 5 3/4".

[knowhereman]

I just check the length of my wing rod that ?I fly in my 900 and its 8 1/2 inches long. Your seems short. I would go with your gut and make it longer. Mine has carbon capped spars and fibre glassed roots and I can winch launch it with the best of them.

[2motheus]

Thanks for the additional information. It looks like there's no single right answer. I'm home now and just measured more accurately. I have about 3 inches of open tube in each wing (still looks too small), and the fuse is 1 5/8 inches wide. My rod, then, needs to be about 7 1/2.

One thing that raised the issue in my mind was that I received a 10 inch rod with the plane and, of course, it won't let the wings seat against the fuse.

Someone has generously offered to send me a digital file of the plans, so I will look at the plans and again at the plane itself before cutting down the rod. That will be a challenge in itself. It looks like a chromed pin out of an industrial machine. I'll first try the thinnest cutting tool I have - on my Dremel...

Thanks again,

Tim

[jtlsf5]

This doesn't have to be so difficult. The rod should fit the plane the way it was built. This means that the rod should fill the entire tube in each wing and the fuse with no play. Any significant amount of play can lead to a stress riser under heavy (launch) load with one wing taking too much of the load without support if the rod happens to reside mainly in the other wing.

Measure the depth in each wing, measure the fuse, add all three together, then subtract 1/16" so the odds of having to cut again go down. Cut the rod, go fly.

End of problem.

Jim Thomas

[Esprit2]

(Snip)... My question is, "How far into the wing root should main rod go?" The tube in this plane is only about 2 1/2 inches into the wing and seems too short to me. Thanks, Tim

Tim,

Airtronics Wing Rods
......................... Dia x length
Olympic 650 ..... 0.156 x 3.0
Monarch 05 ...... 0.156 x 3.0
Sagitta 600 ...... 0.156 x 5.25
Cadet UT-1 ...... 0.156 x 5.5
Questor ........... 0.156 x 5.5
Super Questor ... 0.156 x 5.5
Olympic 88/99 ... 0.156 x 5.5

Olympic II ......... 0.218 x 5.75
Aquila .............. 0.218 x 8.5
Grand Esprit ...... 0.218 x 10.0

Sagitta 900 ....... 0.312 x 5.75
Sagitta XC tips ... 0.312 x 5.75
Sagitta XC .ctr ... 0.312 x 8.25
Aquila Grande' .... 0.312 x 8.25

Regards,
Tim

[S_Dave]

Here's a view of the wing joiner detail from the RCM plans--and the scale so you can confirm the size. Hope it helps, and GL!

r/Dave

[aireze]

Measure the depth in each wing, measure the fuse, add all three together, then subtract 1/16" so the odds of having to cut again go down. Cut the rod, go fly.

End of problem.

Jim Thomas>> Jim has the right idea. I have built 5 or 6 and after the first one, I always extened the receiver tubes one more bay. Since yours is built, measure, cut, and fly. Rich