Current location for King Malu

Sunday, 18 November 2012

Stress test the electric drive

In the morning we took King Malu over the the wet dock, tied her up with mooring lines and tried the new motor. The aim of this was two fold - firstly to test in controlled environment and secondly to produce a torque graph for the motor when attached to the propellor.

Now for a real sea trial - that was where we headed in the afternoon!

Rob was keen to stress test the motor; but we were concerned that because the cutlass bearing needs replacement, we didn't want to stress the drive shaft too much. We have noticed a little knocking from the movement in the drive shaft from the cutlass bearing wear.

We compromised and took the motor up to 2,500 RPM (maximum is 4,000 RPM) and to our delight found we could got a measured 6.3 knots on a relatively calm sea. This is with the old 2 folding blade propellor, so we are hoping for great things in the new year with the Axiom 3 blade propellor, when we will also have replaced the cutlass bearing.

At that RPM the motor was showing 38C and the controller 36C, so we are very pleased - it shows we have solved the cooling problem for motor and controller. Admittedly it's winter and not summer, but even still, it shows we have the temperature under control.

This is the last day of tests with Rob and Simone, they return to Italy this evening.

See all posts about PropEL Electric Drive.

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