Wendell Folks RV-8 Project - Page 46.

March 10, 2007:  The Saturday session found Wendell working to cut the spinner fiberglass "bowl" to clear the propeller blades.  The Dremel tool with a miniature sanding drum makes quick work of removing excess fiberglass as needed.  He had already removed much of the excess fiberglass from the upper cowl before I arrived after lunch for our usual Saturday afternoon session.

As part of that process, the propeller blades were twisted by hand to be sure the cutouts in the bowl were adequate to allow full propeller pitch control as needed in normal flight operations.  Here is a shot of Wendell drilling the first holes for the screws and nut plates that will finally secure the bowl to the back plate.  A #40 drill bit was used for the first holes in the rear and front plates.  The fiberglass bowl was then fitted in position with a light shining through the holes from behind.   The bowl was match-drilled to the back plate, then the front spinner plate was marked at six evenly-spaced locations in preparation for drilling the holes there.   With the bowl clecoed to the larger rear plate, the front six holes were also drilled with the #40 drill bit.  After that, half of all the holes were drilled to final size to accept #8 screws.

I forgot to take a picture of the spinner after the final fitting was made and the fiberglass "bowl" was drilled and clecoed to the spinner back plate and nose plate in front of the prop hub.  After the screw holes were laid out evenly in the photo above, a plate nut is used for back-drilling the rivet holes to secure the plate nuts.  Three plate nuts are already clecoed to the front plate as Wendell begins drilling rivet holes for plate nuts to be added to the spinner back plate.   Deburring, countersinking, and riveting of the plate nuts will be in the next session.  When those are completed, screws will be used to secure the bowl to the plates, then the other half of the #40 holes will be enlarged to accept #8 screws, plate nuts, etc.

After the propeller was mounted in the previous session, there will be several milestones coming in rapid succession in the upcoming weeks.

March 11, 2007:  A Sunday afternoon session was all about getting the fiberglass spinner shell drilled and countersinked to accept the #8 flat head screws and Tinnerman washers.  About half of the screw holes had already been drilled to screw size.  Plate nuts were added to those locations, then the shell put back on the prop with the original clecoes in place.   The shell was then countersinked to accept the flat head screws and washers.   After all the countersinked holes had screws in stalled, the clecoes were removed from the #40 holes, then the holes enlarged with the #19 drill bit to accept the remaining #8 screws.  The fiberglass shell was then countersinked in the remaining holes.   At the end of the session, Wendell was given the green light to install all the remaining plate nuts and fabricate the filler plates that go behind the propeller blades and get riveted to the spinner backplate.

March 12, 2007:  The Monday evening session was very short since Wendell's daughter stopped by for a visit.  My job tonight was to inspect the remaining holes that were countersinked on the fiberglass spinner, and to help him twist the prop blades for trimming the first filler plate to size.  I also cut out a cardboard template to allow him to build the other piece that gets riveted to the filler plate.

March 15, 2007:  This Thursday evening session saw the first initial fit of the upper cowl between the propeller and the fuselage.  Van's indicated that the gap between the spinner backplate and the front of the cowl should be 1/4 of an inch.  A pair of wooden paint sticks used for stirring paint are good spacers to do the trick.  With a pair of sticks secured to both sides of the spinner backplate, we started to get the dimensions needed for a proper fit.

I had visited Wendell on Wednesday and Thursday evenings earlier this week to get him started trimming the aft edge of the upper cowl to remove the overlap of the upper fuselage skin.  Here is the first photo showing a cut that allows the cowl to sit on the aluminum plates that will eventually secure the cowl to the upper fuselage.

At this point in the fitting process, the adjustments to the aft edge are made with a sanding block in very small increments.  The goal here is to get a good fit all across the aft edge of the upper cowl with the front edge of the upper fuselage skin.   The eventual gap between the fiberglass and the aluminum will be wide enough to allow for primer and paint to be applied to the cowl and the fuselage.