Monday, January 11, 2021

Re: [electricboats] New prop 10KW motor

Actually the boat speed is around 5.6 knots when the regen starts.  My boat gets to that at around 8 knots on the wind.

 

Just FYI.  These are the figures I get when using the motor with no sails up. 

I did the readings in a fairly calm sea.  I have a Catalina 30 tall rig.

 

Catalina 30

Zephyr

boat speed data  8/31/18 - No sails up. Seas calm.

four, 215AH/batteries

Direction

Knots GPS

DC Amps

AC Amps

RPM

Volts

East

2.5

17

33

1110

48.9

East

3.2

31

44

1384

47.9

East

4.0

44

57

1584

47.9

East

4.6

78

90

1912

46.8

East

5.1

105

110

2108

45.8

East

5.2

106

108

2110

45.8

East

5.3

104

104

2100

45.9

West

2.5

7

18

845

48.2

West

3.2

11

22

1014

48.2

West

4.0

27

42

1379

47.9

West

4.6

38

54

1554

47.9

West

5.1

53

66

1727

47.0

West

5.2

68

78

1865

46.9

West

5.7

101

100

2103

45.8

Average

2.5

12

25.5

978

Average

3.2

21

33

1199

Average

4.0

35.5

49.5

1482

Average

4.6

58

72

1733

Average

5.1

79

88

1918

Average

5.2

87

93

1988

 

Rgds  Peter

From: electricboats@groups.io <electricboats@groups.io> On Behalf Of Carsten via groups.io
Sent: Monday, January 11, 2021 10:44 AM
To: electricboats@groups.io
Subject: Re: [electricboats] New prop 10KW motor

 

Hi, Peter

 

You mean that the boat speed should be more than 8 knots, not the wind speed, I guess ?

 

 

On Monday, 11 January 2021, 23:22:16 GMT+8, Peter Zephyr <pcbeckett@gmail.com> wrote:

 

 

Hi Carsten. 

  I don't really know how the regen works. All I can think of is by applying some power to the motor it somehow starts the prop to fee wheel and once it reaches a certain speed the amount of power it generates is greater than what it uses.   I had seen posts by others who have seen this happen and that is why I tried it. I usually get 1 to 2 amps when it generates and the wind has to be above 8 knots.  I have a Sevcon controller. 

 

Rgds Peter



On Jan 10, 2021, at 9:31 PM, Carsten via groups.io <Carstensemail=yahoo.com@groups.io> wrote:



It seems that some of you have actual experience with letting a fixed prop and motor "wheel" when under sail !

This is an option for daycruisers, but probably not for ocean cruising.

 

Any of you have some data (prop size and pitch, speed, Watt input) to make the prop spin for "no drag" ?

 

Peter Zephyr, you wrote : "in this situation the prop actually generates electricity and charges the battery".

If you send power to the prop, how can it generate power ?

Very interesting, so please enlighten us.

 

Carsten

 

 

On Monday, 11 January 2021, 01:34:35 GMT+8, Matt Foley <matt@sunlightconversions.com> wrote:

 

 

Michael, 

 

 With a traditional diesel engine, its kind of all or nothing. Typically you are either sailing or motoring. Motors sailing is an option but generally not an enjoyable one. 

 

With electric you will find yourself almost almost always motor sailing. Lets face it, the wind is usually not quite as strong we would like. If you want to make your prop "invisible" it doesn't take much power at all. If you want to add a little speed, help point higher and get you through lulls, it takes just a little more power. 

 

For those reasons, I recommend going with the most efficient prop you regardless of drag. This way you will have the more range when needed and still have the option of no drag by adding a few watts into the system. 

 

 

Matt Foley 

Sunlight Conversions

Perpetual Energy, LLC

201-914-0466

 

 

 

On Saturday, January 9, 2021, 09:04:25 PM EST, Carsten via groups.io <carstensemail=yahoo.com@groups.io> wrote:

 

 

Michael, consider a big folding or feathering prop, which will give you far less drag.

Then find the proper ratio for engine rpm and prop rpm.

 

A toothbelt solution will give you the opportunity to change the ratio.

 

 

On Sunday, 10 January 2021, 04:29:08 GMT+8, Michael Blackstock <mdblackstock@gmail.com> wrote:

 

 

Thanks for your responses, all. I think I'm just going to go with another stock 2 blade to reduce drag under sail. I plan on utilizing the motor very infrequently, so more speed under sail sounds good to me. 

There are so many resources for Catalina owners, but I thought I would check with you all first. 

I will definitely be chiming back in when I begin my motor and battery install!

Thanks

Michael Blackstock

Cell phone 503-913-8217

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