Streamer D Rocket Build, Finished

The Kevlar line is attached through a small hole in one fin. This allows the rocket to fall horizontally adding to the overall drag and a longer duration.

Notice the NAR number on the lower body. All NAR competition models must have the NAR number on them. That came in handy when somebody brought back my Helicopter Duration model. I had given it up for lost!

Streamer D Rocket Build, Part 5, ASP Streamer

I picked a 4" X 40" streamer from ASP.
This is thicker Mylar than what I am used to, it is 2 mils thick.
I didn't know if the folded streamer would even fit into the BT-5 body, I could always trim it down to a smaller 10 to 1 size ratio.

There is a piece of wire, used as a reinforcement "spine" where the Kevlar line is tied.

The streamer is marked for a tight accordion style fold. It has to fit into a 1/2" diameter BT-5 tube so the folds will be 3/8" wide.

After leaving some area clear for the Kevlar attachment, the streamer is marked with a fine point Sharpie at 3/8" increments.

Sharp folds are made at each 3/8" mark, one over and the next crease under making a zig-zag pattern.

I used the back end of a Sharpie for a good burnishing.

Here's how the streamer looked after seven or eight folds.
30 more inches to go!

At the end you leave 4 or 5 inches clear, not folded.
Set the wire down about 1/2" from the end. Fold the streamer end over the wire and tape closed.

Punch clean holes and tie on the Kevlar.

It wasn't very difficult to fold, hold and slide into the body tube.

The 4" X 40" length was too tight in the tube. I cut off about 6 inches and decreased the width down the entire streamer trying to keep it at the optimum 10 to 1 ratio.

Streamer D Rocket Build, Part 3, Tube Smoothing & Nose Cone Shoulder Fit

The seams on this BT-5 tube were almost non-existent. I didn't fill the seams. I did lightly sand with 220 grit and polished with 400 grit.

The shoulder of the nose cone was a little wider than the outside diameter of the body tube.
With the nose cone in place you can use the sanding block to take the lip down to the tube diameter.
Sand lightly, then run a finger over the joint to feel for any raised "step".







Before the fins were glued on, the tube and nose cone got a shot of filler/primer and smooth sanding to surface. I don't use the filler/primer as a "primer", but more as a filler for any remaining seams or balsa grain.

Streamer D Rocket Build, Part 2, Fins

Normally I wouldn't cut fins with scissors.
But this plywood is only 1/32" thick! It cuts easily if your scissors are sharp.

It was fairly easy to sand an airfoil in the fins. The interior color layers make a good depth gauge when sanding.
If you are inexperienced in airfoil sanding, cut out a few extras for practice.

I used 220 grit on my Great Planes Easy Sanding block.

The upper left corner was rounded off. No reason, I thought it looked sleeker. 

Here's a closeup of the airfoil.
The outside edge (to the left) is also tapered.

The side view shows the airfoil taper from the root edge.

Streamer D Rocket Build, Part 1, Parts

This one was built for the Streamer Duration competition at the recent NARAM 60.
Not much here - 
A 9 3/4" long BT-5 tube, balsa nose cone, Kevlar shock cord, three 1/32" thick plywood fins, playwood ordered from BMS and a 2 mil competition streamer kit from ASP. The streamer is 4" wide X 40" long.

There is no engine block, the engine will extend out the back and get a wrap of tape for retention.

I raided the spare parts drawer for some of the parts.
I found two BT-5 sized nose cones that would work.

I weighed them both, the Estes plastic nose cone weighed three times what the balsa one did! The balsa cone was reshaped (see above picture for the "before") and about 1/8" was cut off the shoulder to get it to the .02 oz. weight.

Streamer Duration Rocket Build, Background

In 1975 I tied for second place in Streamer Duration at NARAM 17. It was luck, I really didn't know what I was doing.
If I remember correctly, it was a 13mm, A engine competition. I probably used an MPC Mini-Jet.

I was surprised after seeing the other competitors models. Mine was finished in bright fluorescent paint. Most other rockets were bare tubes! I thought a smooth finish could get you a higher altitude.

My 1975 Streamer Duration model was based on the OOP Competition Model Rockets (CMR) V.I.P. design. The V.I.P. abbreviation stood for Very Impressive Performer. These instructions were saved in one of my three rocket binders.

CMR tubes were actually thinner than the Estes BT-5 and BT-20s. The seams overlapped and only required smooth sanding - no seams to fill! Nose cones were thin vacu-form plastic. Fins were often 1/32" thick plywood. I didn't know plywood was made that thin until I bought a few of Colonel Kuhn's kits.

The V.I.P. was a very simple design. The nose cone and fins are parabolic.






One feature of the kit was the"pop" launch lug.
It guides the rocket up the launch rod then stays on the rod while the rocket continues on.

Pop lugs are a little tricky to make, the hardest part is bending the wire to shape.

I'll be incorporating many features of the V.I.P. in this build.





I hope I get this story right, it was posted on a forum a few years ago.
TRIVIA: Col. Howard Kuhn hired family to bag up his kits. His son and friends would get bored assembling kits. CMR was headquartered in the basement of a shopping center. Just for laughs, dead bugs were sometimes packed into body tubes and hollow nose cones. Once, I did find a bug in one of my kits. It did catch me off guard until I realized it was dead.