kthielen

Has anyone else had the front dowel that holds the wing to the fuse (via rubber bands) break throught the hole in the fuse? That's what caused my crash today...

The bad news is that I crashed my Aspire...

The good news is that it wasn't all that bad...

Shortly before crashing, the Aspire wasn't responding to my controls, or at least not entirely. I had partial control, but not full control. From about 100 feet up it went into a dive and I was unable to pull out of it. It began to spin download and I notice the wing fluttering right before impact. I had no idea at the time what caused the loss of control, but upon inspection, it appeared that the wing came loose from the fuse due to the dowel breaking through the hole in the fuse.

There is a thin reinforcement on the inside of the fuse body to reinforce the hole. That piece did not fail, but that piece separted from the balsa by ripping the balsa that it was glued to away from the surrounding balsa. (darn balsa just isn't very strong).

Anyhow, that appeared to be the source of the problem.

I was lucky because since the wing was loose upon impact, it came off and was not damaged. The font portion of the fuse was broken up pretty good, but fully repairable. In fact, it's mostly been fixed already. I glued all of the broken balsa together with epoxy and then added a thin piece of oak (1/16") to the inside of the fuse to increase the strength of the fuse where it was damaged. I think this should do the trick. I'll find out tomorrow....


kt

sawdust

My Feedback: (7)

You should do a range check with your radio. You must make sure that your wing did actually fail prior to impact. It may well be that your radio did get out of range and that was the actual cause of the failure.


Do the standard range test with the antenna down and then go out 200- 300 feet with the antenna up and make sure you are not out of range.

When you get an ARF or RTF always look over the plane for bad glue joints. I would beef up the dowel joint areas. And remember don't go over board with rubber bands.

Before you fly it again you will probably have correct the center of gravity. Hopefully you can just adjust the position on the battery.

Here's hoping you have a great second flight.

bob

kthielen

Bob,

After staying up until 2:00 AM this morning to repair it, I got back out today and it flew beautifully.

My guess is that one of my loops yesterday caused the dowel to break through the balsa and thin reinforcement. Upon inspection today, the other reinforcement was separated from the balsa also. I like the recommendation of checking all glue joints before the first flight...

I ended up reinforcing all of the joints with a thin (1/16") piece of oak secured on the inside by epoxy. I'm pretty confident in the joint now. I did a few more loops today at reasonably high speed w/o any trouble. (I know, this isn't an acrobatic aircraft, but it's so fun...)

kt

kthielen

BTW, would you consider 4 rubber bands overboard? 2 straight an 2 criss cross...

sawdust

My Feedback: (7)

Do not do loops with the Aspire! Do not do loops with the Aspire! You will suffer a wing failure if you continue to do loops with this plane.

The Aspire is meant to soar like a hawk. And it is great at that.

If the plane is looping on you it is either out of trim, you have your motor mounted incorrectly- not enough down thrust, you are inexperienced, the plane is way over powered, or all five.

You can correct the over kill on the power by just not using full throttle and applying down elevator when climbing.

If you are intentionally looping the Aspire just stop doing it. Trust me the wing will collapse.

Have fun.


bob

da Rock

kthielen,
The oak ought to hold up....

But next time, keep in mind that almost any wood will provide enough extra support for any structure, especially if the reinforcement is epoxied to the original structure. And oak is about the heaviest wood we can buy. Epoxy and CA often do a reinforcing job all by themselves.

It's also worthwhile for some jobs to simply epoxy or CA a layer of cloth as a reinforcement. And if it's glass cloth, even better. And you can always sandwich glass cloth between a light wood layer to the structure needing reinforcement and make the thing almost bulletproof without much weight added.

I've recently assembled a couple of 60size glowfuel models that had weak looking liteply where regular ply would have been more sensible. One of them simply got a soaking with CA. It is now more than strong enough. The other one got a layer of glass cloth under a 1/16" layer of regular ply. It will still be around after that sucker is balsa dust. The latter got the layer of ply to increase the bearing surface for the wing hold down dowels as well as strengthen the bulkhead structure. The entire thing was marginal in strength and no way the material would have stood up to the isolated stress from the dowels.

We have a wide range of things that strengthen. Keep in mind that lighter airplanes fly higher, faster, slower and better.

kthielen

I tell you what though... 1/16" oak epoxied onto balsa does a nice job of strengthening the dowel holes. I have a lot of confidence in those holes now. I'm sure basswood and spruce would also do the trick, but I'd probably use a thicker amount of those woods. In the end, the few fragments of oak I used probably didn't amount to more than 1/10th of an ounce...

Now I'll feel pretty comfortable doing my loops with this bad boy.....