Carded MMX Estes Sky Writer LAUNCH!

That carded rocketry guy Eric Truax beat me to it!

The day after I sent him the PDF on this rocket he had it built and flown twice!
Thankfully, it was stable.
He modified his with a cardstock nose cone and added a little nose weight.
With the heavier dowel nose cone, mine didn't need any more weight in the nose.

After a few other carded rockets flew, the Sky Writer was next in line.
Countdown, ignition and vertical flight!

WOW - this is one of the highest altitude MMX rockets I've flown.
I know - minimum diameter rockets fly the highest.

For a Micro Maxx, I was impressed by the performance. Too bad they only have one second of delay, it was still going up at ejection.
Nose blow ejection and no damage on landing.

Stop by Eric Truax's website for other great carded rockets and a better explanation of the dry-iron technique to make body tubes: HERE

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I had a Quest MMX engine block left from an old parts order.

I tied some 65 lb. Kevlar to the block and glued it in place so 1/8" of an MMX engine would stick out the back end.

The Kevlar was run through the body. With 10" past the end of the body tube, I tied a simple overhand knot.

In the center of the dowel nose cone shoulder, a hole was made with a sharp, thin awl. The knot in the Kevlar was pushed firmly into the hole.

I cut a straight pin, leaving 1/8" of the shaft below the head. Glue was squirted into the hole over the Kevlar and the pin pressed in place. This is similar to the way Jim Flis does it in his MMX kits, except he uses small nail to hold the Kevlar in his balsa nose cones. With this being hardwood, I can get away with the smaller pin.

That shock cord is hard to get into the body tube. Use the flat end of a dowel to push it inside.

The launch lug is simple enough - That's the end of a Bic pen ink cartridge. It fits very well over a Micro Maxx launch rod.

Rough up one side with 400 grit sandpaper for a better glue bond.

I found the center of gravity (with MMX engine installed) and glued the lug in place with white glue.

I followed with a CA down the seam applied with a toothpick.

You could add a small streamer if you'd like, but it'll be tough to get it in the small tube.

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Apply a bead of white glue to the outside and trailing edges of all four fins.

This seals the edges and prevents any lifting of the plys.

Let dry and sand with 400 grit sandpaper.

Repeat with another white glue bead and let dry.

You may have noticed I didn't draw any fin positioning lines on the lowest white fin band. There is a good reason behind this.

With the tube diameter being so small, any variance in the tube diameter would really throw off any pre-drawn alignment lines. So, the fin alignment is up to you.

Glue four fins, 90 degrees equidistant around the white band (fin can) at the end of the tube.

The trailing edges will be even with the end of the tube.

Where the leading edge joins the body tube, it will be just a little below the top of the white band.

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Now that the fins are dry, they can be cut out.

Using the smaller side (already cut to size) as a cutting guide, use a straightedge and cut through all three layers.

The picture shows the back after cutting. The cuts were made from the other side. This way there is no gluing and cutting alignment problems, especially with something this small.

This method also gives you a rounded leading edge.

This closeup is taken from the root edge and shows all three layers. at the top is the folded over leading edge.

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Cutting out those curves on the nose cone shoulder wrap is tight, so I got out my hole punch.

Set on the smallest tube I could punch out the inside convex curves easily. The outside curves were cut with scissors.



Here's the start of the shoulder wrap.
Just glue the end and let dry before wrapping.
Two wraps around and you should be at the diameter of the main body tube.
Roll the round ends down over the taper of the point.

The pencil lead was drawn in with a Sharpie pen.

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To make the nose cone, I cut a piece from the same 1/4" dowel used to roll the tube.

As it stands now, a nose cone made from the dowel would slide right inside the tube. A built up shoulder will fix that later.

You could simply just turn the dowel in a pencil sharpener to give it the correct sharpened pencil shape. But I was building a downscale.

The plastic nosecone in the Sky Writer kit is a much longer tapered nose than an actual sharpened pencil would be.

I used a pencil sharpener to remove wood and start the point. The long taper was sanded using a block and 220 grit sandpaper.

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The iron melts the dried glue on the inside of the tube, sealing it up.

It's a little like a glue gun. The glue sticks are dry until heated in the center of the gun.

It doesn't take much pressure with the iron to melt the glue. Simply roll the tube over the surface.

The picture shows the tube set against the hot iron surface. I usually put a piece of clean white paper between the iron and tube.

Be sure the tube is clean before using the iron. If there is any dirt or finger oil on the tube, you could permanently set it in place with the heat!

Sometimes the last of the exposed seam won't lay down. Put some glue on one side of a knife blade and push it under the seam. Let dry and iron in place.

It's surprising how strong these tubes are, especially at this smaller diameter.

When making larger diameter cardstock tubes, I let a drop of thin CA run down the inside of the body tube. this insures the tube is closed and hardens it up a bit.

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Sometimes you'll have to take it a step farther.

Heat up water to a boil then turn down the temperature to a very low boil. Steam should still be coming up from the water.

Start the roll, stop, then let the paper absorb some steam.

Then roll a little more, stop and let it soak up some steam again.

Step by step you'll get the entire wrap around the dowel.

Now plug in the iron, cotton setting with no steam.

Here's the hardest part of the wrap process. This is more difficult than normal, the tube is such a small diameter.

Remember you are dry wrapping - the glued tab is already dry.

To get the start of the glue tab to lay tightly against the dowel, use a thin straightedge to press the end against the inside edge.

Roll tightly then check both ends to be sure they are tight against the dowel center. It'll take a few tries to get it right.

When you finish up the wrap be sure the "eraser and ferrule" all line up.

Hold everything tightly as you reach for the iron.

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To roll card stock tubes, I use Eric Truax's "dry iron" technique.
When I first read about this technique I thought it couldn't work. I was very surprised by the great results.

Here a smooth coating of white glue is layed across the glue tab. I'm spreading out the glue using the backside of a razor blade. I like using a flat blade because I can push the glue right up to the yellow color line.

Let it dry completely before proceeding.

This small strip of card stock will need some "training" before it'll roll into a tube.
Always wash and dry your hands before doing any paper forming.

I set the card stock printed side down in the fleshy heel of my hand. Progressively smaller dowels are pressed and drawn across the card stock (away from you) to get it to curve.

Pre-rolling cardstock will prevent creases from showing on a finished model.
I no longer pull shrouds over a table edge to get them to curve. I pre-roll them as shown here.

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Find some appropriate cardboard for the interior layer of your laminated fins.

I mentioned cereal box cardboard, but most all dry food boxes could work well. This is not corrugated cardboard but the thin wall of a food storage box.

Be sure the edges are cut square and true.

White glue won't stick well to the printed side so rough it up with 220 grit sandpaper. Not too much, just to where you remove some of the printing.

Lay a coat of glue on both the undersides of the fin. Lay it over the the edge of the box cardboard being sure the creased bend is fully down on the edge.

Repeat with the other three fins and set this under some heavy books to dry overnight.

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The fins were drawn slightly oversize.

Go ahead and pre-crease the fold line while it's still on the sheet. With staight edge in place, run a dull butter knife or the rounded backside of a razor blade through the center of the fins. This will end up being a rounded leading edge.

Cut out the fins and the main body tube wrap.

Cut them out just inside the black lines. This way you'll end up with white fins with no black edges.

In the picture you'll see how I only cut one side of the fin on the lines. The other half is oversize. You'll see why later on.

Now the fins are folded in half on that pre-crease line.

Make adjustments to the fold making the smaller side lines up with the black edge lines on the oversize half.

Carded MMX Estes Sky Writer Downscale

I drew and built this one today.

If you are a Patreon supporter, email me at: oddlrockets@bellsouth.net and request the

MMX Skywriter PDF.

You can make one right along with this build thread.

This is a carded rocket, or a smaller rocket made from cardstock - specifically business card stock. When I worked at the printshop, most all business cards were printed on 110 lb. cardstock.

You'll need:
The PDF printed out on 67 or 110 lb. cardstock

(Better print two, that tube is hard to roll)

1/4" dowel for tube rolling and the nose cone

Cereal Box Cardboard

Patience - This thing is small!

First up, clear coat the printed PDF.

You can see I've masked the glue tab and the lowest white band where the fins will be glued. Clear coat doesn't help with adhesion but it will help keep the print clean.

I didn't include fin placement lines. With the tube diameter so small, any variance in the rolled diameter would affect the cruciform fin layout.