From: jsvrc@rc.rit.edu (Doctor FORTRAN, NAR# 25615)
Subject: Re: How do you make a Vellum Rocket?
Summary: It's in T minus 5
Originator: jsvrc@rcmain.rc.rit.edu
Keywords: competition, duration
Organization: RIT Research Corp
Distribution: usa
Date: Thu, 30 Jul 1992 02:29:39 GMT

In article <1992Jul29.003244.24657@uva386.schools.virginia.edu> wayne@uva386.schools.virginia.edu (Tony Wayne) writes:
>I've seen a few comments on rec.mod.roc about peaople making
>body tubesout of vellum paper for some altitude competitions
>over the past months.  I was wondering... 

Most of the details are spilled in a brace of recent articles in _T_Minus_5_,
the newsletter of one of sections of the NAR. If you're a member of an NAR
section, ask if the section gets _T_Minus_5_. Most sections participate in
a newsletter exchange.

>1) How is this done? 

After cutting a piece of drafting vellum to the desired size (length is
however long you want your finished tube to be, width is the circumference
of an engine, plus a little bit for a glue tab), apply white (Elmer's-type)
glue to the glue tab and let it dry. On the other side, apply a piece of
trim Monokote (tm) just above where the engine will go. Now fire up your
tacking iron to medium. (If you don't have a tacking iron, ask Mom if you
can use her steam iron -- but you'll need to set it to medium-high.)

Wrap the vellum rectangle around a properly-sized form. For 13mm skinny guys,
use a 17/32" brass tube from the hobby store, or a 1/2" dowel with a layer
or two of masking tape. Apply heat with the tacking iron, and the glue should
melt & quickly re-set, leaving you with a nice, light airframe tube.

Make three fins out of 1/32" contest (really light) balsa wood. Glue them to
the airframe.

An inch long "ejection plug" of styrene foam is used to (a) protect the
recovery system, and (b) help provide stiffness. What's styrene foam? The
generic name for Styrofoam (tm), a Dow trademark. Use the brass tube to cut
the plug from a hunk of packing foam.

>2) How is the engine mounted?  

With tape & a prayer. About 5-10mm of the engine is left sticking out the
aft end of the rocket. It is held there with tape. If you don't use a high
thrust engine, like an A10-*T, it _should_ stay put.

>3) Is a standard balsa nosecone used?  

Well, it starts out in life as a standard balsa nose. The vellum tube has
a smaller OD than BT-5, so you'll need to sand it down. Partially hollowing
out the nose is usually done. Don't use a screw eye -- cement your button-
thread or Kevlar (tm) shock line in place.

>4) Do they vellum rockets use a tumble recovery?  

No, although you could do so for fun flying. Vellum birds are a competition
breed, used in Duration flying. Hence, they are required to deploy a
streamer / parachute of a minimum specified area.

>5) Is the vellum paper rocket really that much lighter than the
>   cardboard tube body?

Would you believe 4 grams (most of which is the recovery system)? In a word,
yes!

>6) How sturdy are these rockets ...i.e. can C5's be used in
>   them?

I have never flown anything larger than an A3-6TM in one. My suggestion is
master the technique using 1/2 A3-4T, which are widely available. You'll
have a better idea after you've exercised the medium a little more (and,
hopefully so will I).

>7) Did I ask every possible question?

No. But I do not have every possible answer. Not even close. The _best_ way
to learn about Vellum rockets (and many, many, many other interesting things)
is to join a section of the NAR.

==John Viggiano (Doctor FORTRAN), jsvrc@rc.rit.edu
NAR# 25615
From: bo@hpfcmgw.FC.HP.COM (Bo Viger)
Date: Fri, 24 Jul 1992 19:55:07 GMT
Subject: Rocket/Missile Reference Material?
Organization: HP Fort Collins, CO