Spinner

The spinner is the pointy thing attached to the propeller–it’s the forwardmost part of the airplane.  On this airplane, it consists of two aluminum bulkheads (look like discs) attached to the propeller with a fiberglass “point” attached to the bulkheads.

First step is to mount the bulkheads to the propeller.  That’s fairly simple, though you need to read the propeller manual to know the torque value for the bolts.

The fiberglass comes as a solid cone, so you have to carefully create the cutouts for the propeller blades.  The plans say to estimate the fit, cut, measure, cut again, measure, and repeat until there’s about 1/8 inch gap between the fiberglass and blade.  Or, you can use this cutout that Hartzell (the propeller manufacturer) provides: http://s3.amazonaws.com/n819k/8068D_Van’s-Hartzell_Cutout.pdf.  An added bonus is that it also accounts for the blade in all positions, which is important, since the blade twists in its mount depending on different flight conditions.

After the cone is cut out, I made sure the fit was good, then drilled all the screw holes through the cone into the bulkheads.  I also had to create aluminum covers that go “behind” the blades, to ensure a consistent opening around the blade.  Then one of my least favorite jobs–mounting nutplates–which involves drilling rivet holes, countersinking those holes, then riveting the plates on.  Then we were done!  Here are some pictures of the process (and our messy workbench).