Estes Aries SST, #1927, Build, Part 9, Sanding The Rudder Edge Angle

The root edges of the rudder fins have to be sanded at an angle.

Mark the flat root edges shading with the side of a soft pencil.

The picture on the right shows the angle sand about halfway through. The pencil shading gives a better contrast so you can sand the line evenly.

I'd recommend using a sanding block, like the Estes Ultimate Sanding Bar. To reach a 3/4" dihedral height, the sanding angle is not very steep. 

On the right, you can see what's left of the pencil line. Sand until the pencil shading is gone - no further.

With a weight on one side of the rudder assembly,

Raise the other outside edge to 3/4".

Estes Aries SST, #1927, Build, Part 8, Engine Mount & Re-gluing A Wing

The Kevlar, elastic and heat shrink wrap are pushed down and through the engine mount for gluing into the main body tube.

With the Kevlar line, shock cord and heat shrink tube out the back of the engine mount - 

To get the lines out the top, I made a hook out of a coat hanger. Slide it into the top, hook the wire on the shock cord and pull through the front of the tube.

 

After the glue set up on the wings I double checked the alignment. It was off, enough that one wing was cut off and repositioned.

Be sure to cut into the glue, not into the tube when removing a fin.

The engine ribs are glued 3/8" from the root edge.

I cut a strip of tape, 3/8" wide to use as an alignment line.

The picture shows a dry fit, no glue yet.

Note the rear of the rib, it overhangs the rounded trailing edge. The back end of the rib was sanded back, just to the start of the rounded edge.

Estes Aries SST, #1927, Build, Part 7, Engine Shrouds

A comment by Naoto K. has proved true!

Those round leading and trailing edges cause the engine shrouds to overhang the balsa.

With the front of the shroud pulled back a little from the rounded edge, the rear of the cardstock overhangs the trailing edge.

I tried the fit of the shrouds over the middle rib.

The rib height is good, at 3/8" away from the root edge, it's just a hair off center.

I trimmed back the back side of the shroud to better fit at the rounded trailing edges.

The rounded wing trailing edge also required trimming back the middle rib.

There was some surface cracks at the sharp folds. The thicker the cardstock, the more likely the folds can start to break up.

I brushed on a thin coat of white glue, keeping the glue on the fold, not down the sides.

After the glue dries, some light sanding can smooth some of it out.

Estes Aries SST, #1927, Build, Part 6, Engine Shrouds

I wanted to make the shrouds out of something a little thicker than the regular 110 lb. cardstock. I had some thin posterboard for years, it's about time to use it! It's also shinier on one side - perfect!

The templates were printed on cardstock, the posterboard would be too thick to run through the printer. Shrouds were traced onto the the posterboard with a sharp pencil. Fold lines were added.

Emboss the folds before cutting out the shroud.

I always use a un-serrated butter knife tip and a metal straightedge. 

Gently coax the folds little by little to keep the the edge clean. I did get some slight breaking of the paper fibers. More on this in the next post.

The fold was worked in over my aluminum angle, rubbing the line with a burnisher.

The right and left engine shrouds, almost ready for assembly.

There will be some adjustments when fitting to the model.

Estes Aries SST, #1927, Build, Part 5, Fin Grain Filling

The balsa pieces and launch lug were first filled with CWF and sanded to surface using 400 grit.

All pieces were taped down to cardboard for some spraying with filler/primer.

While the filler/primer was still wet, you can see the remaining balsa grain that should disappear after sanding.

I still had a few small spots where the grain was deep.

Some CWF was pressed on using a finger.

The pic on the right side shows the same wing after sanding to surface. The balsa is filled and sealed.

Estes Aries SST, #1927, Build, Part 4, Smaller Fin Fitting

The root edge of the Rudder fins is slightly longer that the outside edge.

I marked the root edges with pencil.

The hand cut engine ribs were a bit higher than the fold height on the engine shrouds.

I sanded the top down until it fit just inside the dashed lines.

Double check the length of the engine ribs when set next to the 3/8" spacing from the root edge. Sand the rear end if needed until flush.

Estes Aries SST, #1927, Build, Part 3, Larger Wing Fins

The straight cuts were made with my break off blade knife.

Save your curved lines for an X-Acto style #11 blade.

That rear curved cut can be sanded by wrapping some 400 grit around an engine casing.

The Estes instructions suggest rounding the trailing edges of the wing. Pay attention to the single rounded leading edge of the engine rib.

I only rounded the flat side of the trailing edge near the root edge. Rounding an inside curve is difficult and unnecessary.