Current location for King Malu

Saturday, 15 June 2013

High Speed test

We finished the install of the HUI. The punchdown panel, which is still in first generation proved a useful step forward. Doing the first install with this showed up a number of improvements which we'll put into the next version.

The PropEL HUI worked extremely well. It was great to be able to see everything you need (RPM, battery volts and amps, temperature of motor and controller etc) at the helm position.

The new buttons that Tim had sourced made it look really chic I thought.

So what of the High speed tests themselves? Up till now we had only taken PropEL drive train up to about 1,300 RPM (shown on the HUI photo) and we knew it worked well up to that speed but had been reluctant to push it further till we had completely secured the large drive pulley on the prop shaft. The extra washers for that had come with the HUI panel so now it was time to push it further...

At 1,500-1,800 we noticed a speed increase and ability to go into the waves/wind better. We had about 12 knots of wind on the nose for the test and we could push up to nearly 2,000 and get 5 knots of boat speed.

About 2,300 RPM and we noticed a vibration of the mounting which made us decide to investigate before pushing further. This has been our approach all the way along - to take a slow conservative approach to testing, checking out each and every potential problem and fixing before proceeding. The aim is to develop a secure and reliable electric drive that many yachts and boats can benefit from.

With the HUI and throttle now installed and working reliably Tim was comfortable to take King Malu into the marina under PropEL power. The mooring went smoothly despite a 15 knot cross-wind. Afterwards over lunch we talked through the test. One thing Tim noticed was that King Malu stopped and responded very much quicker than with the Honda outboard.

This is what is expected with an Axiom Propellor. We are partnering with Axiom on development of propellors as part of the integrated PropEL system (that's King Malu on the home page of their site) so this was encouraging that their design worked as predicted.

See all posts about PropEL Electric Drive.

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