The plot thickens

For those who might be reading this blog hoping for engaging stories of unusual places and interesting people, sorry, today is about motors.

I’ve now figured out how to add more trials to the plot and show the three separate days on which tests were done with the Torqeedo.  It definitely more colourful – But whether its useful remains to be seen:

The red series is the first day we tested the Torqeedo and there were 8 people on board, and the motor was jury rigged in position in the well. That might explain why both the other test days, (yellow and blue) show higher top speeds.  But its odd that low speed the red line is the best – that is, not drawing much power to maintain the speed.

And I had hoped that the streamlining of the flaps would have helped make her faster at all speeds.  But doesn’t seem so.

But I think this exponential regression plotting thingo is influenced by the number of observations.  And so if going one way I was engaged in conversation and didn’t take many readings, and then coming back I was focussed and took many readings, well maybe that skews the graph towards the side where many readings are taken.

Its sure to get better as I collect more information and learn more about how to interpret it properly.

3 Replies to “The plot thickens”

  1. Hi Chris,

    I’m also the owner of an old racing boat (A Room with a View, a 53′ cat) that I’m in the process of making more cruising friendly, including electric propulsion. After a long, long wait for delivery of the epods I’m now wondering whether they were the right choice…it sounds like you’ve had all sorts of trouble with yours, and after 12 months I’m still waiting on delivery of fairings and controllers. They also don’t look all that well put together.
    I’ve read your tests of the Torqeedo with a lot of interest, but I can’t help wondering if 3.5 kW (even two of the cruise 4s) would provide enough power to motor against strong wind/ tide. It sounds like you’ve been pretty happy with the Torqeedo on Current Sunshine though. What are your thoughts?

    Cheers Juris

  2. Hi juris,

    Its a pity that we’ve had to find out the hard way about Epods. The other Australian Epod customers I know, Bryan and Tarci, are both dissatisfied with the product and the service. And Bryan has just in the past few weeks decided to abandon the chase and switch to Torqeedo. His use may be interesting to you because he has a 44 ft Oram cat which will be a closer match to your needs. He did a test on the Brisane River before making the decision and with one Torqeedo was able to get about 5.5 knots. This is an estimate of still water speed deduced from a couple runs with and against the tide.

    My boat is on the hard as yet, and so I don’t have any further experience, other than whats already on this blog. So seeing how she goes into strong winds will have to wait a little longer. It’ll still be a few weeks before she’s back on the water.

    An interesting point of comparison between the Epod and Torqeedo is its efficieny. Based on my tests in the river here and my records of use with the Epod, I estimate that the Torqeedo is twice as efficient as the Epod. And in Bryans tests he has found the same thing. To be more specific about what I mean… at a given speed the Torqeedo uses half the power of the Epod.

    For me this is critical because I don’t plan to use a genset, and so it means the range I have with a full battery is now doubled. Or to put it another way, its like having another bank of Lithium batterys, and at $10,000 it makes a $6000 Torqeedo look like a good deal.

    I’m also impressed by the service from Claude, the local distributor. Its a breath of fresh air after my experience with Re-E-Power.

    Even though the Epod is supposed to be more powerful than the Torqeedo, in practise it is not so. And so whatever the capability of the Torqeedo against wind turns out to be, I am confident that we’d be better off than with an Epod.



  3. Hi Chris

    I am still considering the Torqeedo for my little sailboat and I actually found a local boat shop where I could order it, though they don’t have them on stock and there is no possibility to test it before buying. However, I am still reluctant since the other owner of a torqeedo-equipped trimaran in Germany had problems with the 2.0 R which according to torqeedo seemed to result from the remote control. It turned out the problem was not solved by the new control and appears randomly: The engine will just stop running and not budge whatever he does until he switches remote controls. When it eventually stops (He didn’t tell the intervall) switching back will help again. I hope it’s only a problem with his unit but until his problem is solved I won’t buy anything. The season in Germany is over for now so I will have to wait for next summer. I asked this german guy if he would like to join the torqeedo group on yahoo. So maybe it will be possible to exchange experiences with him in the future.

    I hope you will be spared from any further engine disappointments


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