Author: microskiff cat

Measuring an outboard motor’s propeller shaft length

Some of our clients who already own an old outboard motor, and others who contemplate buying a used one, ask us how to measure the length of an outboard motor’s propeller shaft, in order to know for sure that the motor indeed complies with the 20″ long (L) standard that Wavewalk requires.
This is an important question, because Wavewalk kayaks and boats work well only with outboard motors that comply with the 20″ long (L) standard set by outboard motor manufacturers, and our company strongly recommends not to use short shaft (S) standard motors.

The full answer is –
For this matter, the propeller shaft length is measured from the inner top side of the motor’s mounting bracket to the horizontal anti-ventilation plate that’s above the propeller.

Note that sometimes the anti-ventilation plate is called anti cavitation plate, although this is an incorrect term.

In many cases, this distance between the inner side of the motor’s mounting bracket and its anti ventilation plate can be slightly bigger than 20 inches, and if this is the case, it’s a good thing.

If the distance you measured is under 20″, it inevitably means that the motor does not comply with the 20″ (L) standard.
In fact, most outboard propeller shafts are slightly longer than their stated standard. For example, the length of a 2.3 HP Honda L shaft is 22.5″, and the length of this motor’s short (S) version is 16.5″. Similarly, the length of a short-shaft (S) 4 HP, 5HP and 6 HP Tohatsu is 17.1″.

But don’t fool yourself –  16″, 17″ and 18″ is not 20″, and it’s still a short-shaft (S) outboard, and therefor, it won’t serve your purpose.

Why is a motor’s shaft length important?

The reason the outboard’s propeller shaft’s length is so important is that it determines both the propeller’s immersion below the surface, which is critical to its proper functioning, and the distance between the propeller’s highest point and the boat’s lowest point, which is critical for trouble-free and effective operation of the boat.

Do not use 15″ short shaft (S) outboard motors with your Wavewalk 500, 700, and S4.
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Storage space for duck hunting gear on board the Wavewalk 700

By Chris Henderson

Duck hunting is coming to a close and I only have 2 or 3 trips left. We are hoping for a great hunt this Friday and one more hunting video! But one of the questions I often get is “How much storage space is there in a Wavewalk?” People see the saddle and think that there would not be enough room for your decoys and all the gear that usually accompanies the sport of duck hunting. So I thought I would make this video to show people how we pack our W700 for a duck hunt. On our typical hunts we put all the gear and deeks and one hunter in a W700 and other hunters paddle their own W500s. We usually run 3 dozen decoys. Rather than keep the decoys in their bag and just throw them on top (which is very doable), we prefer to put them inside the hulls where they act as ballast and actually make the boat more stable vs. on top where they exert a stability cost. You have to take them out of the bag when you get to your spot anyway. 3 dozen deeks is all we need/want for where we hunt. A person could get more in if they needed to. Can’t wait to see how the S4 hunts.

Sneak peek – How the Wavewalk S4 is coming into being

This morning, the mold makers we contracted to produce the cast aluminum rotational mold for the S4’s twin-hull part (we’ll use the W700 saddle for this product) sent us this picture with a technical question, and we thought that some of our blog readers could be interested to see it:

 

What this image shows is the rear part of a large size bloc of solid wood, from which a computer-controlled cutting machine called CNC Router cut the form of the S4 that we designed.
The CNC router took the information it needed for cutting the wood out of the Computer Aided Design (CAD) file that we produced with a CAD software program.

Once all adjustments and polishing are done, the mold makers will coat the solid wood pattern (dubbed ‘plug’, or male mold), and use it to produce two concave molds called ‘sand molds’, into which they will cast molten aluminum. One of these molds will have the shape of the top part of the S4, and the second mold will have the shape of the bottom part.
These two parts will be used to make the aluminum mold (tooling) for molding the S4’s twin-hull part.
That aluminum mold will be polished and coated with Teflon, and the mold makers will encase it in a steel frame they will build around it.
The steel frame will enable attaching the rotational mold to a large size rotational molding machine that will rotate it in a rotational molding oven big enough to allow for this truck-size object to move freely in all directions.