Monthly Archives: June 2022

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Gear Leg and Wheel Fairings (1)

20-Jun-2022 15:44 ⋅ Leave a Comment ⋅ Mark

Aligning and fitting the wheel pants required use of two lasers, one for the aircraft centerline and one for accurately locating the pant retention bracket holes.

The fuselage had to be leveled, then raised so wheel installation would leave the wheels just touching the ground. Here the wheel dollies from Charlie Derk (with many thanks) were removed for actual wheel installation.

The main wheels and brake fixtures were bolted into place. Again the plane was leveled and wheels just barely touching the ground.

A .75″ x 1.0″ spacer block established the upper position of the main wheel pant. With the forward and aft sections clecoed together, alignment to aircraft center and level reference datum could proceed.

A regular construction laser provided an accurate centerline for the airplace. Measuring offsets to this reference line and the front/aft of each wheel pant ensured parallel alignment. The pants were also measured from the floor to their own centerlines to make sure they were parallel with the ground.

A second construction laser provided accurate location of the holes drilled in the retention brackets. The same processes described above were used with both main pants and the forward wheel pant.

The forward wheel was first installed, then the side breakout pull of ~25lbs was measured with a baggage scale. The Nose Fork Assembly nut was tightened to approximately achieve this value. I have heard from other builders that this nut will need adjustment many times during the fly-in period.

All wheel pants drilled and temporarily clecoed in position in the left photo. Forward wheel pant protectors were then aligned and holes drilled to prevent two bar damage.

Finally for this section, the pant retention brackets were surrounded with resin/silica to provide larger bearing surfaces during normal flight operations between the fiberglass and the brackets. Additional resin will be applied in a later post to round over and slightly enlarge the bearing points.

MISCELLANEOUS

The door windows were retaped prior to the next batch of final paint.

The inital painting of the horizontal stabilizer left a few runs and some flaking along the trailing edge of the upper side. Resanding and air brush priming were performed before another (hopefully final) paint coat was applied.

The #2 cylinder fuel injector line required two adel clamp locations to secure between the prop governor cable bracket.

Spinner and Cowling (2)

20-Jun-2022 13:54 ⋅ Leave a Comment ⋅ Mark

More fitting and body work has been associated with the upper and lower cowling. The sequence I used for painting the cowl parts: cut and fit the cowl as needed, sand/putty for initial prime, attach hinges and fasteners, Smooth Prime, sand/spot putty, prime again, scuff with Maroon scotchbrite, and final paint. Splitting the lower cowl before final prime to accommodate a three-bladed prop was a difficult process.

Fitting the lower cowl bracket and bending the air outlet louvers were the beginning final cowl preparations.

Holes for the Skybolt camlocks were drilled with a Unibit into the lower cowl where the air scoop will attach.

Superfil was applied to the air inlet ramps of the upper cowl for smooth airflow into the engine compartment.

Sanding the air inlet ramp and application of resin/glass bubbles to secure the Rod Bower scoop inlet piece were also done.

Drilling for the nose connection screws and aft pin retention block were completed on the upper cowl before the final separation.

Fishing line (hard to see in the left photo) provide a trace line for the center cowl center. The lower cowl was held together with a forward custom retaining piece while a curf-less saw started the cowl splitting process from the aft side.

Further splitting of the lower cowl continued with the scoop installed until full separation was achieved. The split process was nerve racking, but seems to have been successful.

On the left, the lower split cowl near the aft section is shown held together with a custom retaining piece. On the right, the side hinges were then riveted using a pneumatic squeezer.

Side piano hinges are shown with intermediate and final rivets.

A thin layer of West System resin and colloidal silica was spread to the upper side hinge rivet lines. After 24 hours of cure time, the layers were sanded smooth before Smooth Prime was applied. Another round of sanding in preparation of the final prime coating.

Here the rivet lines on the firewall hinges for the upper cowl are filled, then sanded smooth.

After the first coat of primer was applied, some body work or spot putty was needed in some locations. Those areas were then sanded smooth for another round of priming.

After the initial prime, Skybolt fasteners were applied to the lower cowl halves and the lower firewall brackets. All the parts were then sanded again and reprimed.