Sensenich Prop 72...85 Install

Remember! Remember! Remember! to order the "special" front plate from Van's so you will not have to have it express shipped...ask me how I know :-)

I ordered my prop about five months before I actually needed it so it was no stretch for me when it took 20 weeks to get here.

Installing it was no big deal. Since there is a great deal of rotating the prop to balance and drill on the spinner, I removed one plug from the top of each of the cylinders and stuffed rags in each one of the holes (see above picture).  I also removed all the plug wires and grounded the mags.  You can't be to careful when dealing with a forty pound prop.  After that, I just needed to uni-drill the special front plate out to the 1/2 inch holes required for my prop.  The bolts and spacer come with the prop so it was just a matter of putting the bolts through the drilled out front spinner mounting plate, then through the prop, then through the back spinner mounting plate, and finally through the 2+ inch spacer.  Some liberal use of a rubber hammer may be required to get the prop started but once the prop bolts catch they will pull the assembly together.  Torque to the manufacture's specs and start hacking away at the spinner.

I used Sam Buchanan's method of drawing a circle on a piece of butcher paper and folding it in half to find the half way points on each side of the back of the spinner.  Once marked, I used the manufactures template to draw the cutouts for the blades.

At first I made my initial cut at a 1/4 inch inside the template traced lines.  After considerable sanding, I found that the original template was a perfect fit.

There is a recommended gap of an eighth inch to keep the spinner from scoring the prop which I will add after I make the back filler plates.  I attached the spinner on to the back plate with cleco side grips so I could do the necessary adjusting.  I then put a mark on the forward most point of the spinner with a magic marker and pushed a ladder up to the point and watched it as I rotated the prop.  This worked out great and only took a few tries to get a perfect balanced fit.

Constructing the back filler plates was no big deal, I just used the original cutout template and started hacking away at it until I had something that I could lay down behind the prop and fill in the space.  It's suggested that you can use ether .040 or .063 aluminum as material for these plates.  I decided to use .040 since it was easier to work with and exactly matched the thickness of the spinner fiberglass.  I ended up with two pieces for each side that looked like this.

These will be riveted behind the prop on to the spinner back plate and will not come off when the spinner shell is removed.  More to come soon.