NARAM Egg Lofter Build, Finished

I can hear the readers now: "Paint adds weight! Why are you painting a competition model?"
It's just me, I like a smooth, colorful model.

The glue fillets on the natural wood fins showed up on the finished model. Not a big deal, just something to could watch for the next time around.



My competition builds are old school, it's all I know. I just don't have the recent competition experience to know the latest trends. I'll be happy to participate at NARAM and get some qualified flights.

NARAM Egg Lofter Build, Part 9, Smaller Shroud & Pop Lug

I realized there would be a problem with the long shroud. How can I make vent holes for the altimeter with the shroud in the way?
While I would have liked the long shroud for less drag, I needed more body tube exposed below the shroud for the vent holes.

I went back to PayloadBay.com and printed up another.
TIP: Note the glue tab is narrower at the bottom and the corner angles are steeper at the bottom (see arrows) This helps with a flatter fit at the tube joint.

I formed a clean, narrow glue line for the bottom of the shroud at tube joint. I takes very little glue to hold paper to paper joints.

No centering ring is needed for inside support. The open top of the shroud is supported by the fit against the egg capsule.

I had some Apogee Fly-Away guides for 13mm and 18mm body tubes. These weren't high enough to clear the egg capsule. Apogee sells a guide for use with the egg capsule, I just didn't see it.

I'm glad I saved all my old instruction sheets! Here's the old CMR pop-lug with standoff for egg lofting. This might be a second version of the pop-lug with the smaller lower wire hook.
There is also small segments of body tube that better hold the wire on the standoff.

The fit of the pop lug is very good with clearance for the launch rod.

NARAM Egg Lofter Build, Part 8, Fin Airfoil Shaping

The fins were made using 1/32" thick plywood. I was able to cut them out with scissors, something you couldn't do with balsa.

Mentioned in an earlier build, you can easily gauge the thickness by seeing the ply layers as you sand the airfoil.

The fins got a wipe of CA and smooth sanding with 400 grit.

Notice there isn't any CA glue near the root edge. I wanted the fillets to better adhere to the body tube.

Here's how the first attempt looked before I realized the altimeter and pop lug problems. Too bad, the long shroud would really smooth out the air stream.

The fins were cut off to be reused. The body tube and shroud were thrown away.

NARAM Egg Lofter Build, Part 7, First Shroud Attempt

I went to the Payload Bay website to use the Transition Tool.
http://www.payloadbay.com/page-Tools.html

I figured a long shroud would reduce drag.
The problem is, with this long a shroud, how do punch hole for the altimeter or use a pop launch lug?
I didn't think about this until after the shroud was on the model. More on this later.

At the narrow base of the shroud, I rolled the Sharpie over the glued edge while the glue was still wet to smooth it out.








The shroud was printed on 64 lb. card stock. Normally I use 110 lb. card stock for shrouds but I wanted it lighter.
The whole shroud got a wipe of CA glue to stiffen it up.

Here's how the first shroud fit against the egg capsule and body tube.

Like I mentioned, how would you punch vent holes or use a pop lug?

NARAM Egg Lofter Build, Part 6, ASP 18" Parachute Kit

The parachute is "spike folded" to find its center. Mark the center point with a Sharpie.

The shroud lines are pre-cut. Even up the ends and fold at the center. Mark the center with a Sharpie.





Set the center mark on the shroud line at the center mark on the parachute.

Tape the shroud line at the corner side of the parachute.

Here you can see the marked center dot on the chute material.
Set the center mark of the shroud line directly on top of the center mark of the Mylar.

1" away from the center dot, place another tape strip over the shroud line. Place another tape strip 1" to the right of the center dot.




On the right side another tape strip is set over the shroud line at chute the "corner".

TIP: Notice the tape holding the line steady for the tape strip placement.

NARAM Egg Lofter Build, Part 5, ASP 18" Parachute Kit

I purchased some Hang Time "Over Easy" parachutes from ASP Rocketry.

This parachute is designed for NAR Eggloft Competition so it is reinforced. The shroud lines run over and are taped to the top of the canopy. 1/4 mil Mylar and 18" diameter.
I also have some 12" Mylar parachutes. I'll pick the best chute on the day of the launch.


A strip of self-adhesive Mylar is supplied for shroud line adhesion. The builder cuts the strip into 1/4" wide pieces.

The Mylar strip was taped down for the 1/4" marks.
The wax paper backing was marked with a fine point Sharpie.

The strips were cut with a knife and straightedge. I only cut the Mylar and not to the outside of the waxed paper backing. This kept all the pieces together.

After the shroud lines were removed from the flat spool there was angles creases in the lines. Chances are these lines are some sort of poly blend. The line bends could be trouble when packing the chute.




TIP: Straighten out the lines by pulling them under a hot iron. Don't set the iron too hot, you don't want to melt the shroud lines. Try first at a low setting. If the lines still have folds, increase the heat setting.
Set a towel over the lines to dissipate the heat.

Apogee Fly-Away Rail Guides, Build, Part 3, Finished

Double check the fit around a body tube. I painted my competition models and the fit was a little tight. The rail guides didn't immediately fly off the tube when released.

I wrapped some 220 grit sandpaper around a body tube and sanded the inside diameter slightly larger.

The instructions recommend painting the guides a bright color. Apparently they can fly off and land 10 feet from the launcher. A bright fluorescent color will be easier to find on the ground.

After painting the small rubber bands were pulled into the slots to join the two halves.

Here's how they fit around a BT-20 tube.
Notice the stretched rubber band at the bottom.
At the center top is the "T" shaped halves that slide into the launch rail.

These fly-away rail guides are another great example of what can be made using a laser cutter.