Etek Electric Outboard Motor Project
version 1.1
The first tests exhibited a lot of turbulence from the prop, so in this, pic I've added a cavitation plate above the prop. The component fairy came by and brought me some Interstate Deep Cycle golf cart batteries. Tom Burke, the local Interstate distributor has been helpful in providing technical info on batteries. I also found a Curtis 1204 PWM controller salvaged from a golf cart. The installation shown here is still 36 volt because of the voltage limitation of the controller and the wiring is for test purposes only.
We went out to the water again to splash around a bit. The Curtis controller worked well and starting is no longer a death grip situation. The addition of the cavitation plate reduced the prop ventilation a lot and improved the performance. The boat is heavier because of the weight of the golf cart batteries and in a test run with 2 people on board and a total weight of approximately 1000 pounds the top speed is still 5.7 mph.
For the top speed of 5.7mph, the amps was 75-80 at 36v = 2700 watts = 3.61 hp x .91 efficiency = 3.29 hp.
That's an increase of 350 pounds over the previous test and the speed is still the same. Using the controller, speed was reduced to 3 mph and the current draw at that point was 20 amps.  At wide open and 36 volts the motor is turning at a maximum of around 1800 rpm while the old Johnson motor was rated for 4,000 - 4,500 rpm, so with gear reduction in the lower unit the prop is currently about 1200 rpm. Practicality says that changing the gear set isn't going to happen.My next experiment will be to modify the prop or get or make a larger prop

Go to update page click here

email: jmrudholm@psnw.com

You are visitor number31370