Elevator Finito - Part 5

Note: The series of tasks photos used are not in chronological order.

D Nose

The material used to manufacture the D Nose distorts easily and that's why it was placed under the top skin as my attempt to achieve a flat skin resulted a puckered look but there was a positive as packing was required to align the skin to the mass balance.

Comment: Keep the skins is a safe place and do not separate from factory packing until needed. Handle as little as possible as this aluminium is very soft and will damage easily.

With the D Nose skin matched drilled  and cleoced the elevator assembly now removed and the remaining holes drilled then the D Nose was removed. All swaf was blown out and the D Nose de-bured carefully then primed on the inside face, top edges and allowed to dry.

The D Nose was installed using the factory M3 x 8 pop rivets. 

Mass Balance Faring

A misalignment at the top side of the outer rib for the mass balances meant that packers had to be cut from 0.020'' scrap as required. These were installed in varying lengths and combinations along the area affected with the goal to taper or average out the misalignment and prevent a deformation if the skin was riveted to the face of spar. 

Packers Port Side

There was no science just plain old "suck and see"  based on if it looks good it is good.

At assembly the various combinations especially the single hole packer had a drop of Loctite 380 Black Max Super Glue applied and cleoced to dry.

Mass Balances

Next the skin for the mass balance was trial fitted to check alignment to the tip faring. The mountings for the mass balances had been installed previously in the assembly following the factory drawings. Due to the thickness of the flange each hole on the inside face was counter-bored with a 5.5 mm drill to a depth of 3 mm to allow the factory rivets to be used

Checking balance with mass weights
Note: A small amount of the rib is marked
for removal to clear faring

When installed it was noted that the elevator assembly did not achieve positive balance, so an extra 60 mm OD x 7 mm thick washer was added to both sides which meant the M10 lock nut had to be placed on the outside of the outer rib and tightened. 

Factory installation

The mounting blocks for mine were installed before this was noted by the builder. A existing hole was enlarged to accept the 10 mm shaft and this allowed four [4] pop rivets to be used as it would be bad news if a weight ever broke free. I will speak to the factory about the required balance and if more is required it would be done with led shot and epoxy. 

Adjusting flanges

Packers after riveting

Extra weight added

Assembled mass balance faring.
Note: Tips are ready to install and the skin was 
fitted as a final operation with the tips

Fitting Fiberglass Tips : Stab

With the elevator re-mounted and chocked into alignment allowing the tips fairings to be installed and aligned with all the mounting tab's for the fairing's installed previously. 

Starting at the port side, the tip was sanded slowly until it look right - it was that scientific. All sanding was done using 80 grit paper on a flat surface at the start. A taper was required and it was started on using a 300 mm disc sander with a 125 grit and finished using a sanding stick and 80 grit paper.  

Fitted then marked and sanded again and again till the correct look was achieved. 

Note: One side had to be sanded generally to achieve the correct appearance - these were not just a square sand. 

 

Port tip ready to install
note tilt

Once satisfied the fiberglass faring was match drilled to its tabs and fixed with M3 x 6 counter sunk pop rivets.

Port tip installed

The starboard tip was approached in the same manner except the location of the outer tip was used as a reference using a marked stick to transfer the location from the port to the starboard side.

Note: The fuselage was level for this task allowing the floor to be used as a fixed reference. After riveting the end of these tips are a absolute weapon, care has to be exhibited when moving past them

Checking starboard tip location using marked stick

Fitting Fiberglass Tips: Elevator

The right line - following the red line

Elevator was chocked into it correct position for level flight allowing the tips to be aligned. After the first fitting it was decided that the end of the tip had to be opened to allow the tip fitting to begin and was achieved using a hand saw.

Open end elevator tip as it was
found it was to tight at the rear

The procedure was the same as the tips with the edges having to be sanded differentially to achieve the right line. The best technique to determine how much to remove was to hold the tip hard against the top skin or bottom skin and rotate it till it contacted the opposing skin. Check the line and if incorrect rotate the tip on the over size side into the correct position and then using a finger to feel the gap then sand the appropriate side - repeat and repeat.

Note: The amount to be removed was marked using a Sharpie pen and a finger as the guide to transfer the estimated amount to be removed to the faring - then sand - repeat.

With all these task's completed the elevator was removed again and the mass balances weights, tips and fairing skin installed.

The final task is wiring and this is for the next blog. 

Finito is Italian for finished