Blades and Brackets

The metal for the propeller blades and hub arrived. They were purchased from Online Metals.Com, which turns out to be located maybe 20 miles from my house. Their prices were reasonably competitive, and their price to cut the metal to the proper length was acceptable, too.

I bought 2 sets of 304 stainless bar, and one set of 316 stainless cut from plate. If worse comes to worse I have spares with which to work on or to replace a prop if one gets lost.

I also purchased round aluminum bar stock, enough for three hubs, and 3/4 inch round Delrin stock to be used for plain bearings.

Following Rick's instructions, I carefully measured and marked the grind lines on both sides of each bar. I then marked the grip lines, the pivot points and the zero angle lines. All was ready for bending them to shape.

Rick's instructions described how one mounts the blades vertically in a vise, with a right angle ruler to ensure the blade was truly vertical. He then used a protractor and a stationary reference to make sure that when the blade was twisted that is bent to the correct angle.

I decided that this was too much work. Anyway, I didn't have a fixed protractor like Rick's, but I did have a nifty angle measuring tool I picked up years ago from Sears. It is a 360 degree dial protractor that has one flat side which one applies to the surface to be measured, and the gravity driven plum bob need swings down to the lowest position against a marked dial. You then read the angle directly from the dial.


In the past this tool has been invaluable for measuring bike frame angles and the like, and measuring the stuffing box angle on the boat.

For the propeller blade situation I merely rotated my vise 90 degrees so the jaws were in the vertical position, and clamped the blade in place. One quick measurement of the blade made certain that it was horizontal. Grasping the blade at the grip line with a large adjustable wrench with one hand and countering the weight with my other hand, I was easily able to bend the blade to the desired angle.

Repeating the process with the blade inserted at the other end and the job was done.

All in all, it took maybe 5 minutes to bend the 6 blades.

The 316 stainless, being about .005 inches thinner than the 304 bar, definitely was easier to bend. Hopefully this won't be a an issue when those blades are called upon to push water.

Putting the blades aside for the moment I then began work on the mounting brackets for the outriggers.

At first I planned to do something along the same lines as the Cadence outriggers. That boat uses UHMW plastic blocks drilled and sliced in half with mounting holes drilled on either side to clamp the two pieces around a short section of larger fiberglass tubing to the top of the float.



The problems with this are 1) the blocks are somewhat heavy, 2) I couldn't find a reasonable and inexpensive source for it, and 3) this requires some sort of threaded receiver on each stabilizer.

I had already purchased T-nuts for this purpose. However, having second thoughts about mounting them, the weight of the bolts, the lack of adjustability and reduced strength, and the extra work needed, I decided instead to mount the brackets directly to the top of the stabilizers.

The hull mount will still use the T-nuts, though they will be the longer ones with wider bases. This will still allow vertical adjustment.