New Way Letter - Go Build, Part 7, Tube Seam Fill

I like to mark the tube spiral indents with a sharp pencil. It makes them easier to see when applying the CWF filler.

I dip just the tip of my X-Acto knife in the thinned CWF filler.

You won't need much, so wipe the excess off the back of the knife tip.

Run the tip into the seam recess with a back and forth motion. The blade directs the filler into the seam.

I dip and fill about one inch at a time.

I had hoped the plywood fins would only require

There were a few "splinters" that needed some CWF and sanding.

New Way Letter - Go Build, Part 6, Filler/Primer On The Fins

The fins are plywood and don't require CWF filling used with deeper balsa grain.

Here I've taped down the fins over the fin tabs, keeping he filler off the wood for a better glue bond.

Here's a fin after spraying with filler/primer.

Note the tab and root edges didn't get sprayed.

After sanding,

there is some filler/primer left and filling the slight wood recesses.

There were a few deeper slivers that needed a bit of CWF and sanding to smooth out.

New Way Letter - Go Build, Part 5, Engine Mount Gluing

Run the Kevlar line out the back of the engine mount.

I set the engine mount beside the main airframe tube to mark a dowel that will apply a glue line inside the tube. Note the pencil line where the glue will contact the upper centering ring.

Glue was applied to a dowel end and transferred inside the tube.

The mount was slid in with 1/8" of the engine hook exposed out the back end.

A length of heat shrink tubing is supplied to slide over the Kevlar line and down to the top of the engine mount. The tubing protects the Kevlar at the low end from the ejection charge.

To be honest - 

I didn't remember to slide the tube down the Kevlar line!

Here's some shrink wrap on Kevlar before and after being hit with a heat gun.

Considering how hot a heat gun is, the shrink wrap sleeve should give good protection to the Kevlar line 

Roll the Kevlar to keep it out of the way when sliding the mount into place.

The lower centering ring got a glue fillet smoothed out with a Q-tip.

New Way Letter - Go Build, Part 4, Engine Mount

The upper plywood ring has a engine hook notch.

For added strength, glue in place over the upper bend of the hook.

Notice the Kevlar notch is to the outside of the ring edge to keep the line away from the ejection charge. The upper ring is plywood, strong enough for the ejection pull on the Kevlar line. 

The lower ring is thick cardstock. 

The completed engine mount with the engine block glued in to top.

The Kevlar line is knotted tight around the tube.

I've set the knot with a small drop of wood glue.

NEVER use CA glue (Super Glues) on shock cord or shroud line knots. It will make the string or elastic brittle and prone to easily break.

Cut the line with wire cutters.

Here's how the Kevlar sits in the outside notch of the upper ring.

I set the looped line into the centering ring glue fillet. The loose tail is also pressed into the glue.

New Way Letter - Go Build, Part 3, Engine Mount

The bottom edge of the engine mount tube got an interior wipe of CA Glue.

Then the edge got a quick coat.

Then sand the edge square, flat and smooth with 400 grit.

This shows the engine hook retaining ring, not glued on yet.

Always be sure your engine hook runs straight down the tube after gluing the ring over it. The hook can slip around so check it before the glue sets up.

The upper centering ring is plywood.

The fit was a bit loose so I added a thin line of wood glue to the inside edge to get a friction fit.

Let the glue dry before doing a second dry fit.

New Way Letter - Go Build, Part 2, Cleaning Up The Letter Fins

The letter fins are cut from 3/32" thick plywood.

The edges are slightly laser charred. The flat faces were sanded with 400 grit on a block to remove the ash.
 

On the left - 

is a before and after sanding the fin edge. 

On the right - 

The inside tighter curves were cleaned up using small half round diamond files.

The laser edges are cut with a slight "wedge" cut.

The picture shows the wedge cut sanded down about half way. You can see the angle of the laser cut.

This sanding is most important on the root edges so the fin sits squarely onto the body tube.

Finish up by just kissing down any rough edges with a light pass of 400 grit.

You don't have to put a rounded edge on the fins, just knock off any roughness.

New Way Letter - Go Build, Part 1, Parts

Rick from New Way sent me a prototype for a upcoming kit.

The LETTER - GO is a robust BT-60 design, but with a custom fin design.

The fins spell out your name from left to right going around the tube!

The fins are laser cut plywood and thru the wall.

. 

The kit should be available after this summer's NARAM. The kit doesn't include the shorter fin attachment tube and letter fins. You send back the coupon with your name request and your custom letter fins are returned to you. Your name could have three, up to six letters. The number of fin slots will be custom cut to fit the length of your name.

This could be a great personalized Christmas or Birthday gift for a rocket flying family member.

Here's the specs. 

It's almost the size of a Big Bertha. It might be upgraded to a 24mm mount As the fin root edges don't reach the motor mount tube. 

All the parts:

A multi-sized (12, 18 and 24") parachute.

Kevlar (with a blue shrink wrap tube for ejection charge durability)

The engine mount as a cardstock lower centering ring and a plywood upper ring. This gives extra strength for the Kevlar line looped beneath the upper plywood ring. 

Parts of interest:

Water slide name decal with vinyl trim strips

Small metal chute ring for chute attachment

Engine hook retainer ring

That blue shrink wrap tube that goes over the Kevlar line

Two of the letter fins spelling out my name

The New Way sanding and Q-tip build bag.

Porthole Tube Fitting - Tip

For the new ROBOT prototype, I needed to fit short tubes, glued horizontally to the (vertical) main airframe tube. 

These are a like the "portholes" on the old Centuri Skylab model, only larger in diameter. 

To see the Centuri Skylab: CLICK HERE

Wrap some 220 grit sandpaper around your main airframe tube.

Sand the tube end against the sandpaper with a back and forth motion, to the left and right. Sand in a straight line.

Try holding the smaller tube still and moving just the larger tube with the wrapped sandpaper.

On the left, the curve sand is about half way through. More sanding is needed until - 

You get the best fit with no gaps.

The outside layer skin will tend to fold under.

Lift out with a fingertip and lightly sand off with some 400 grit. 

 

Here's a good fit of the Robot head on the neck tube.

This technique rarely comes up, but could come in handy one day.

Not A Tri-Fold Mount - Tip

This type of shock cord mount feels stronger than a thin paper ti-fold mount. It can be used on BT-55 and larger tubes. I wouldn't recommend using this in a BT-20 or BT-50. In smaller diameter tubes, the shock cord knot might block the ejection of a parachute.

Cut a rectangular piece of body tube, from the same diameter as your main airframe tube.

Tie your shock cord around the rectangular piece.

 

Glue into the body tube with the tail of the shock cord pointing up. The rectangle mount is already rounded to match the inside curve of the main airframe tube.

Be sure to recess the mount deep enough to clear the nose cone shoulder.

This shock cord mount design was used in some Centuri kits.

D.I.Y. Couplers - Tip

I needed a coupler "sleeve" to fit a Centuri sized ST-18 (1.8" diameter) tube.

This is for a second prototype of a possible Odd'l Rockets ROBOT kit.

You can't find couplers in this size so I'll have to make one using a 1" length of the ST-18 tubing

Cut the coupler in a straight line using scissors.

Slip the cut coupler and mark the overlap with pencil.

On the left, you can see the pencil line.

Cut off the overlap, not directly on the line, but a little large.

Test the fit in the outside tube. 

Is it is too tight, you can sand to fit with some 220 grit on a block. 

Enlarge the right side picture to see a perfect fit in the tube.

Engine Burr - Quick Tip

Before sliding an engine into an engine mount tube - 

Check the top end of the engine. Many have roll over "burrs" that can start fraying a BT-20 size tube. This can happen with the thin blue (Estes) or yellow (Quest) engine mount tubing. 

You can compress the burr down by rolling on a hard surface.

Better yet -

Sand off the burr using some 220 grit on a block. Just roll off the end.

Here's the rounded, sanded off burr.

Don't take off too much, just enough so it doesn't rub or lift the inside layer of the spiral wound tube.

Estes Advanced Target Drone, Kit #1913, Build, Finished

A clean design with high contrast decals.

The intakes are a highlight.

Wing fins are wide.

The rudder and strake fin on the other side are asymmetrical.

The nose cone is simply red, clean with no canopy.

Out of the ordinary from other standard 4F/NC rockets.

 

Estes Advanced Target Drone, Kit #1913, Build, Part 16, Overlay Decals

Sorry I missed a day, I was camping with no internet!

The Air Force logo is centered on top of the white decal set down earlier.

Before doing an overlay decal like this, be sure the white underlay is completely dry.

The USAF letters are centered onto the white rudder stripe.

The ATD 0416 decal was white in the Estes kit, I printed it in blue. 

Set onto the red paint it almost looks black.

To get a good center position of the three white side decals, center and mark the paper template.

At the top of the tube you can see a small piece of masking tape with a center mark. 

Set down the background white underlay decal first,

Let dry and follow with the Air Force decal.

Look close and you can see the white decal underneath. But, it's close enough for me.

Estes Advanced Target Drone, Kit #1913, Build, Part 15, Intake & Decal Fixes

The white intake decals ended up being too long, they overhang the wing fillet joint.  

I redrew the decals to a closer fit.

If you build this model, your decals may be too long depending on how your cardstock intake fits.

After the decal dries, it's easy to cut and lift off the excess.

The black intake decals were also too wide and wouldn't fit inside the mouth of the intake.

These were trimmed to fit.

I don't usually use clear coats,

but on these white paint decals I rolled some Future acrylic on the edges with a Q-tip. This is just extra insurance that they won't roll up along the edges.