What exactly is... [BAR questions]

What exactly is... [BAR questions]

Post by Tom Emerso » Sat, 28 Sep 1996 04:00:00



As a "born again" rocketeer, I'm seeing terms & such that (usually) make
sense, but some topics either didn't exist when I was working with these
15-20 years ago (or maybe it was the fact that 15 years ago I was in grade
school and not interested in some of these subjects...)  With that in mind,
I'd like to know:

What exactly is "reefing" a parachute?  the only parachute modification I'm
aware of is cutting out a "spill hole" in the top of a plastic chute, but I
hear references to "reefing" chutes and it seems they are applied to nylon
chutes and chutes considerably larger than 24".

What are/where can I get "microballoons"?  What else do I need to know
about using these?  I see references to these for strengthening body
tube/fin joints.  While I've never had a rocket "shred" on me yet, I
suspect I'll need to know this as I delve into the realm of HPR...

What is C2 (while I'm on the above topic)?  Is this cryanoc-whataever
(crazy glue, hot stuff, etc) or is it a newer/better adhesive?

What is the original price of the Estes pro-series Patriot missile? (4-D
engine)  When I stopped into a small hobby shop the other day, the
proprieter pointed to a wall with exactly 1 "starter kit" and 3 bagged
models saying "that's my selection at the moment, but if you want, I can
get/order anything out of this catalog" (as he hands me the 96 estes
catalog)  Not realizing the pro-patriot is "unavailable" until that very
moment, I asked about that.  He has a price of about $62, but his supplier
is "out of stock" [no surpise at this point], but it got me to thinking.  I
think I've seen someone asking $80 for it, and I'm wondering if/when Estes
will re-introduce it and if so, how much would it really be worth?

Of course, any other related stories about things you've learned in, say,
the last 20 years of rocketry will be eagerly read and digested/commented
on...

Tom

 
 
 

What exactly is... [BAR questions]

Post by Roy Gre » Sun, 29 Sep 1996 04:00:00


Quote:

>What exactly is "reefing" a parachute?

this is the practice of shortening the shroud lines (temporarily) so
that the chute presents a smaller area to the airstream.  It has been
used in model rocketry for years in attempts to get back rockets on a
windy day.
Some HPR fliers are attempting to use dynamic reefing to reduce
opening shock, since they seem to have trouble ejecting chutes within
two seconds of apogee.  The way they are trying to do this is by
placing the shroud lines through a ring that on packing is placed
about halfway or further up the lines to the canopy.  the idea is that
the chute will open small, yet force the lines to spread out, making
the ring slide down, letting the lines get longer, until it is fully
open -- this process would take a few fractions of a second longer
than the chute opening fully all at once.

Quote:
>What are/where can I get "microballoons"?

they are tiny hollow glass beads in a powder consistancy.  They have
been used in model airplanes for decades for the purpose of bulking
and thickening epoxys for various types of molding, particularly wing
and control surface fillets. These fillets are much lighter than a
pure epoxy fillet.  It doesn't make the fillet any stronger -- it is
used mainly cosmetically.
How the idea that it strengthens a joint got started is beyond me.

Quote:
>What is C2 (while I'm on the above topic)?  Is this cryanoc-whataever
>(crazy glue, hot stuff, etc) or is it a newer/better adhesive?

hmm.  never heard of that...  maybe you're thinking about ready made
fiberglass sheets  (G10?) that are used to make fins for HPR.

Quote:
>What is the original price of the Estes pro-series Patriot missile?
<snip>
>  He has a price of about $62

That's about right.  the 93 catalog has it for $59.95

 
 
 

What exactly is... [BAR questions]

Post by Scott Johnso » Tue, 01 Oct 1996 04:00:00


Quote:


> >What exactly is "reefing" a parachute?
> this is the practice of shortening the shroud lines (temporarily) so
> that the chute presents a smaller area to the airstream.  It has been
> used in model rocketry for years in attempts to get back rockets on a
> windy day.
> Some HPR fliers are attempting to use dynamic reefing to reduce
> opening shock, since they seem to have trouble ejecting chutes within
> two seconds of apogee.  The way they are trying to do this is by
> placing the shroud lines through a ring that on packing is placed
> about halfway or further up the lines to the canopy.  the idea is that
> the chute will open small, yet force the lines to spread out, making
> the ring slide down, letting the lines get longer, until it is fully
> open -- this process would take a few fractions of a second longer
> than the chute opening fully all at once.

> >What are/where can I get "microballoons"?
> they are tiny hollow glass beads in a powder consistancy.  They have
> been used in model airplanes for decades for the purpose of bulking
> and thickening epoxys for various types of molding, particularly wing
> and control surface fillets. These fillets are much lighter than a
> pure epoxy fillet.  It doesn't make the fillet any stronger -- it is
> used mainly cosmetically.
> How the idea that it strengthens a joint got started is beyond me.

> >What is C2 (while I'm on the above topic)?  Is this cryanoc-whataever
> >(crazy glue, hot stuff, etc) or is it a newer/better adhesive?
> hmm.  never heard of that...  maybe you're thinking about ready made
> fiberglass sheets  (G10?) that are used to make fins for HPR.

> >What is the original price of the Estes pro-series Patriot missile?
> <snip>
> >  He has a price of about $62
> That's about right.  the 93 catalog has it for $59.95

I think Tom meant CA, aka SuperGlue.  Its great for tacking things
together quick.  But since its brittle, its good for emergency field
repairs or as I do, use to tack wings on and them glue them the rest oif
the way with epoxy & fillet, etc.
I think its called CyanoCrylate or something like that.  Nonetheless,
its CA for short, and is better known to average consumers as
SuperGlue.  You can get CA from just about any good hobby store. Don't
get the SuperGlue that you know of in the green tube...

My Question is:
Where can I get "microballoons"? What is a good manufacturer?  WHere can
I get some?  I've never used them with my epoxy jobs...but it sounds
very usefull!

 
 
 

What exactly is... [BAR questions]

Post by Roy Gre » Wed, 02 Oct 1996 04:00:00


Quote:



>> >What are/where can I get "microballoons"?
>> >What is C2 (while I'm on the above topic)?  Is this cryanoc-whataever
>> >(crazy glue, hot stuff, etc) or is it a newer/better adhesive?
>I think Tom meant CA, aka SuperGlue.  Its great for tacking things
>together quick.  But since its brittle, its good for emergency field
>repairs or as I do, use to tack wings on and them glue them the rest oif
>the way with epoxy & fillet, etc.
>I think its called CyanoCrylate or something like that.  Nonetheless,
>its CA for short, and is better known to average consumers as
>SuperGlue.  You can get CA from just about any good hobby store. Don't
>get the SuperGlue that you know of in the green tube...

yea, you're probably right.  should've taken the context into
consideration.

Quote:
>My Question is:
>Where can I get "microballoons"? What is a good manufacturer?  WHere can
>I get some?  I've never used them with my epoxy jobs...but it sounds
>very usefull!

Any well stocked hobby store should have it or be able to order it.
Sig sells it in a squeeze bottle.
 
 
 

What exactly is... [BAR questions]

Post by Bob Kapl » Wed, 02 Oct 1996 04:00:00


Quote:

> Where can I get "microballoons"? What is a good manufacturer?  WHere can
> I get some?  I've never used them with my epoxy jobs...but it sounds
> very usefull!

Any good hobby shop will have them. SIG has them. Places that sell glass and
resin for homebuilt aircraft have them.

If you still can't find them, baking soda makes an acceptable substitute,
especially for making fillets with CA.

        Bob Kaplow      NAR # 18L       TRA # "Abort, Retry, Fail?"

 
 
 

What exactly is... [BAR questions]

Post by PaulDimi » Wed, 02 Oct 1996 04:00:00



Quote:

>I think Tom meant CA, aka SuperGlue.  Its great for tacking things
>together quick.  But since its brittle, its good for emergency field
>repairs or as I do, use to tack wings on and them glue them the rest oif
>the way with epoxy & fillet, etc.
>I think its called CyanoCrylate or something like that.  Nonetheless,
>its CA for short, and is better known to average consumers as
>SuperGlue.  You can get CA from just about any good hobby store. Don't
>get the SuperGlue that you know of in the green tube...

CA (Cyanoacrylate) is great for treating both ends of a BT to reduce wear
and tear as well as dents and zippers.  I use it for tacks as was
mentioned above.  But I also use it for paper to plastic and wood to
plastic bonds.  It comes in at least three types: Thin  (or hot), Medium
(or Gap Filling) and Slow (or Thick).  Thin dries fastest and does not
fill well.  It is great for wicking under paper shrouds and into tight
places.  Medium is decent for most applications.  Thick is decent where
you really need some filling.  It's the slowest to set.  

You can buy "Kicker" which is a liquid spray that accelerates the setting
of the CA.  It will set almost immediately after Kicker is sprayed.  But I
understand there is some loss of strength resulting from using Kicker.
However, there are some instances where it really helps when trying to
hold two pieces together that don't want to stay together.

Buy the hobby store stuff.  Super Glue isn't as good.  I do use Super Glue
for my BT treating though.

Just thought I'd add my experiences since adhesives is always a great
topic for a rocketry thread!

Paul.

Fly Baby Fly!