rwithey

My Feedback: (3)

I finished my SS 40 MKII ARF with an OS46AX. I did not think about this till after the maiden flight...then though hmmmmm.

I have built a few kits - SIG LT-40, SIG 4*60, Goldberg Tiger 60- and every one required glassing the wing joint with CA. The SS ARF did not mention doing that in the instructions. I did epoxy the joiner and both ribs very well, but shouldn't the joint be glassed with CA? Maybe I am a little over cautious, but I just re-kitted the 4*60 on it's 3rd flight. That however was not a construction failure....but a dumb*** failure. Put a ST G90 in a plane designed for a maximum .75 2stroke. In a fast dive the ailerons fluttered and stripped both servo gears in an instant (Hitec HS425BB's) at about 30 feet it rolled onto its top and lawn darted. The poor new ST90 required new bearings and carb, but is running again and waiting for a bigger bird.....maybe a TF warbird.

Anywhoooo.....should I worry about the wing joint or not?

Thanks,
Rob

waagbuck

My Feedback: (1)

I built the GP super sportster kit and the ARF and did not glass the wing joint on either. Never was a problem.

johnboyrc

If you followed the directions, you won't have a problem. The ply joiner is strong enough as is, adding more to it will just add unnecessary weight. Mine has held up fine for 2 years now.
How was your maiden flight?

Primodus

My Feedback: (56)

ditto.

glowplug

My Feedback: (1)

Yep, never had a problem with mine either.......and it's seen some serious G's.

MinnFlyer

My Feedback: (4)

Glassing the wing joint comes down to one thing: Engineering.

Many kits I have built use a 1/16" ply wing joiner on each side of the spars, and the LE dowels simply go through the balsa LE and anchor to the front wing joiner. Glassing makes the wing joint much stronger by incorporating the center sheeting into the mix. It also strengthens the LE where the dowels protrude.

I remember when my dad built a Chipmunk and decided that the thin wing joiner wasn't going to be strong enough, so he replaced it with 5/16" ply... By doing so, he figured that glassing the center wasn't necessary - and he probably would have been right, except that he did an outside loop - At the bottom of the loop (Plane inverted, pulling back up toward the belly) the dowels were pulling the entire load of the fuse and, due to the fact that they had no fiberglass support, ripped right through the wing.

With most ARF's, since they are already covered, the Mfgr usually wants to avoid the glassing step, so they are designed around a stronger wing joiner, making glassing unnecessary.

The bottom line message I got from my dad's mishap: You didn't engineer it, they did - so do it like they tell you.

Of course, once you know what you're doing, mocifications are up to you, but KNOW what you're doing first!

rwithey

My Feedback: (3)

Thanks for the info guys, at least now I know I don't have to worry about it!

Rob

sseward

My Feedback: (1)

My first one got driven full throttle straight into the ground (all my fault), and I can tell you, the wing joint held up through that! If you epoxy it they way the say, you'll have no worries.

Steve