Beginner's Questions

Beginner's Questions

Post by John Mirel » Fri, 03 Aug 1990 03:43:59



Having built three of the Estes rocket kits in the recent past, I am
wondering if hot glue is a suitable replacement for white glue in
gluing balsa wings to the cardboard tubes. Also, one of the kits has me
gluing pieces of paper on the balsa wings. Is this for reinforcement?
Is it really necessary?

One kit has foward swept wings with winglets on the tips. I didn't think
it would be very stable in flight. It was very stable until my 6 year-old
crushed the wings pulling the rocket motor out. Are the winglets the source
of the stability. I can't believe that it's the forward swept wings.

John Mireley

 
 
 

Beginner's Questions

Post by nur iskand ta » Fri, 03 Aug 1990 06:02:30


Quote:

>One kit has foward swept wings with winglets on the tips. I didn't think
>it would be very stable in flight. It was very stable until my 6 year-old
>crushed the wings pulling the rocket motor out. Are the winglets the source
>of the stability. I can't believe that it's the forward swept wings.

>John Mireley

Forward swept wings add stability at low velocity regimes, because
the tips do not stall. The problem is making them stiff enough
to resist divergent aeroelastic twisting forces. DARPA recently
flew a fighter-type airplane (X-32?) with forward-swept wings. The
forward-swept wings also reduce induced drag by reducing (or eli-
minating) tip vortices.

Iskandar Taib

 
 
 

Beginner's Questions

Post by Ed Proch » Fri, 03 Aug 1990 21:50:07



Quote:

> Having built three of the Estes rocket kits in the recent past, I am
> wondering if hot glue is a suitable replacement for white glue in
> gluing balsa wings to the cardboard tubes. Also, one of the kits has me
> gluing pieces of paper on the balsa wings. Is this for reinforcement?
> Is it really necessary?

> One kit has foward swept wings with winglets on the tips. I didn't think
> it would be very stable in flight. It was very stable until my 6 year-old
> crushed the wings pulling the rocket motor out. Are the winglets the source
> of the stability. I can't believe that it's the forward swept wings.

> John Mireley

I have tried using hot melt glue in a couple models. I found some
pros and cons.

pros:
 the joint is very strong on the smooth surface of the boby tube.

 It takes only one pass to build up a fillet.

 It is quick. "drying time" is essentially nonexistant.

cons:
 I suspect that (but have no evidence of) the joint with the
 porous balsa is weaker than with white or carpenter glue.

 I have not yet gotten a smooth fillet.
    I have tried going back over the joint using
    the glue gun tip to smooth it out, but
    no good results yet.

 strands and strings of hot glue get in the way.

 Some paints do not adhere to the glue very well.
    I used Hot fuel proof dope and it took
    several coats with long dry times in between.

Things I have thought of, but haven't tried:
 coat the joint area of the balsa with white glue to fill in
 the voids. then the hot glue joint can adhere to the nonporous
 dried white glue surface.

 applying something else to the hot glue fillet to smooth it out
 (Actually, I have tried spackling compound. It worked, but I don't
 like the work it takes to make it stick to the nonporous hot glue.)

 using a hot air blow drier to keep the glue soft for smoothing.

I will probably abandon hot glue for any model that I want
to look really slick. But for prototype models, it is fast
and strong.

Keep flying!

Edward J. Prochak   Voice: work-(216)646-4663  home-(216)349-1821

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