Propellerless outboard motor technology
The Fin5 is the first outboard motor from the young French company FinX Motors . After several years of development, the company has finalized the adaptation of its diaphragm technology from industrial pumps to boat propulsion. The distinctive feature of the Fin5 is that it has no propeller. Instead, the propulsion force results from the displacement of a flexible diaphragm by means of magnets, without any rotating parts or gears.
Testing the Fin5 on a tender
We tested the Fin5 in the basin of the Port des Minimes in La Rochelle, on a small 2.70 m Zodiac dinghy. With a power output of 2 kW, which the manufacturer compares to a 5-hp petrol outboard, the Fin5 weighs in at 20 kilos. Although this is starting to take its toll on the carrier, it remains in the transportable category, weighing 5 to 7 kilos less than its combustion-powered rivals. At the same time, you need to carry the battery, the weight of which will depend on the desired range.
Classic installation
The outboard is mounted on the transom in the conventional way, using two screws to press it onto a chair or transom reinforcement. The operation is quick and easy. A well-placed, ergonomic handle is used to tilt the base out of the water. If there's no propeller to remove, it's always a good idea to take the membrane out of the water.
On the electrical side, integration is a little less optimized. Connection to the 48V FinPower 3500 battery on our tender is via two flying leads.
Good thrust and maneuverability
Once the magnetic key has been magnetized to the end of the tiller, it's time to cast off. The high torque of the motor, an advantage of electric power, is further enhanced by the diaphragm. The maneuver to leave the pontoon in forward gear is extremely easy, with two people on the dinghy, but can also be performed with a loaded boat returning from a race.
The motor is quiet, and the few vibrations felt are explained by the manufacturer as being due to the use of a long shaft on our test run, rather than a short shaft which would be more suited to our tender. Maximum speed is not the objective of the diaphragm technology, which favors torque over thrust, but our tender reached a satisfactory speed.
Here, it's impossible to reverse the direction of rotation of the propeller to move backwards. FinX therefore came up with a simple mechanical method for reversing the motor. While the solution is elegant and works, it doesn't take long to wrap the electric cables around the outboard's head. On the other hand, you'll appreciate full power when reversing.
Innovative, elegant solution
We appreciate the Fin5's elegant design and the membrane's advantages in terms of maintenance and safety. If it proves its robustness over time, the Fin5 could appeal to boaters who are not primarily interested in speed.
The Fin5 is offered at a 2023 price of ?2,900 excl. tax, which is quite close to the 3 kW market price.
