Sunday, May 30, 2010

[Electric Boats] Re: On-line education?

 

Capn_Earl,

The education part of electric boating is indeed problematic:
1. boats are for play, not work
2. sparse knowledge, spread thinly
3. industry experts have "day jobs"
4. most experts don't know they are
5. how to stay informed and impartial?

As the next step forward, many have called for comparable on-the-water watts/speed/distance measurements, so potential buyers can compare apples and oranges. There is wide consensus that this would be very helpful.

The step after that, is probably what you are calling for: impartial education resources. Thanks to our tireless moderators, this ElectricBoats list is about the best there is for both steps, though it is like reading 30 large textbooks.

Trying to simplify, "AWeekDaySailor" started a Wiki early 2008 (in the links section: "An FAQ for eBoat design"), but it lacked wide-spread participation. He then offered "A Beginners Guide" (in the links too) that is very meaty and digestible.

Even more basic, GreenMarineRePower offers a free "Primer" pictorially introducing some basics of boats, fuels, and propulsion. We are trying to arrange day jobs, so the above two steps can be worked on more quickly. Everyone else is too busy to invest the 5000 person-hours required to provide a broadly researched, well documented, comprehensive, time and money accessible education resource.

There are many e-boaters that have made their own informational websites or blogs about their own boats. I find those extremely helpful and informative, but hard to find. Maybe if there was a folder in the links section on ElectricBoats labeled "eBoats", they would be easier to find. I've linked many websites on GreenMarineRePower, by boat type, then size. Most other lists are by boat name, which I find completely unhelpful, unless I already know all about that particular boat. It is like trying to buy shoes by searching online for salespeople's middle names.

Watts/speed/distance - This would be completely marvelous. I am encouraging the development of an auto-reporting wireless data-logger that could be cheaply incorporated in anyone's system. Amps, volts, speed, SOC, temp, logging and display, fire/water/gases/theft/power alarms. One yardstick that's affordable enough for most to use.

In short, I think your call for online education is right on target!

Thanks,
Mark Stafford

--- In electricboats@yahoogroups.com, "capn_earl" <mnixon@...> wrote:
>
> My guess is that there are many folks following this group who are like me and cannot find continuing education courses (especially on-line) to learn more of the operational details of electric propulsion. Books that I have read have gotten me a start but come up short in helping me gain the knowledge that I want to have as a DIY'er.
>
> If there are indeed those kind of on-line resources, I would appreciate any help locating them. If not, it would seem that a group such as Mark Stafford's Green Marine Re-Power foundation would be an excellent place from which to offer courses (for a fee) that could be developed by the industry leaders of electric boating. And in the end, an education/certification process would also help to promote quality design and implementation as well as safety for our new industry.
>

__._,_.___
Recent Activity:
MARKETPLACE

Stay on top of your group activity without leaving the page you're on - Get the Yahoo! Toolbar now.


Get great advice about dogs and cats. Visit the Dog & Cat Answers Center.


Hobbies & Activities Zone: Find others who share your passions! Explore new interests.

.

__,_._,___

Re: [Electric Boats] Safety weekend

 

At 03:29 PM 30/05/2010, Keith wrote:
>It's the controller - and yes it just starts ramping down the
>amperage to cool off, but that can happen at inopportune times. I
>added a fan today and that helps - I've got a Sevcon PMAC mounted on
>3/8 alum plate which in turn has a heatsink - all connected with
>that gooey thermal grease. I have a spot infrared sensor and it was
>showing about 200F on the face of the controller when it went into shutdown.

No fan before? that'd do it! You can have the biggest heatsink in the
world, but if the heat can't get off the heatsink, all it's doing is
buying time.

If you can put a hole or two through the heatsink, you can add a
thermal switch at the face of your plate to heatsink interface to
control the fan. That way the switch will see the heat pretty early.

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=140369787915&ssPageName=STRK:MEWAX:IT
is the ones that I'm putting onto the galvanic isolators that I've
been building for shore power - if the isolator starts to warm up,
sound the alarm because there is current happening where you don't want it.

>I think the 'sensor' on my motor overheating is molten copper being
>thrown about ;) (it's the Mars brushless)

100 amps continuous (says the specs, but that is with "free" cooling,
depends on wether the cooling air out can get away to be replaced by
fresh, cool air). 300 amps for 30 seconds or one minute depending on
whose selling the specs. Axial brushless spins the magnets, so I'd
think the dark and smelly smoke is the first sensor, then the
controller shutting down because the motor not doing as its' told
(naughty, naughty motor) before you'd have any thrown copper snot.

In my opinion, bad practice to run "things" at their limit for long,
if you see the need to run your motor at 100 amps for longer than a
few minutes at a time, I'd be adding extra cooling. I'm sure that
somewhen in the Electric Vehicle Discussion list, someone added an
external ducted blower to an Etek (Mars is a direct replacement for the Etek).

>And BTW...it wasn't all seriousness today - after I got some good
>work done I went out and had one of the best sails I've had in
>months! T-shirt & shorts in 15kts steady (a far cry from last weekend)

Aaahh.. Northern Hemisphere, coming into late spring. Here we've
mostly put away the summer toys... 40 degrees south in the path of
the Southern Ocean weather. Memorable day about 10 years ago (would
have been perfect for electric boating) mid-winters day, one of the
highland lakes, like a mirror. Got to get my trailer finished for my dinghy.

Regards

[Technik] James

__._,_.___
Recent Activity:
MARKETPLACE

Stay on top of your group activity without leaving the page you're on - Get the Yahoo! Toolbar now.


Get great advice about dogs and cats. Visit the Dog & Cat Answers Center.


Hobbies & Activities Zone: Find others who share your passions! Explore new interests.

.

__,_._,___

Re: [Electric Boats] Safety weekend

 

On the wooden boat forum , there is a thread at the moment on safety in electric boats .
One bloke posted of rescueing someone whose electric powered boat was swamped , and of copping an electric shock , and being afraid of battery acid spilling around.
Maybe you experienced people should check in , and maybe comment.
Regards Rob J.


From: aweekdaysailor <aweekdaysailor@yahoo.com>
To: electricboats@yahoogroups.com
Sent: Sun, 30 May, 2010 3:29:21 PM
Subject: Re: [Electric Boats] Safety weekend

It's the controller - and yes it just starts ramping down the amperage to cool off, but that can happen at inopportune times. I added a fan today and that helps - I've got a Sevcon PMAC mounted on 3/8 alum plate which in turn has a heatsink - all connected with that gooey thermal grease. I have a spot infrared sensor and it was showing about 200F on the face of the controller when it went into shutdown.

I think the 'sensor' on my motor overheating is molten copper being thrown about ;) (it's the Mars brushless)

And BTW...it wasn't all seriousness today - after I got some good work done I went out and had one of the best sails I've had in months! T-shirt & shorts in 15kts steady (a far cry from last weekend)

-K

--- In electricboats@yahoogroups.com, James Massey <jcmassey@...> wrote:
>
> G'day Keith, All
>
> At 04:02 AM 30/05/2010, Keith wrote:
> >We've lost 3 good sailors here in CA recently, so I'm spending the
> >weekend upgrading my safety profile. <snip>
> >I still can't sustain > 60amps without overheating, so that's a concern.
>
> Which component/components can't sustain 60 amps? I'd assume only the
> controller or motor could overheat and tell you (anything else would
> just melt down and stop)?
>
> Care to give a basic system description, or do you already have it in
> hand? (If you have it in hand already, please describe your mods).
>
> A controller usually just goes into a shut-down mode, but motors are
> often suffering by the time their thermal switch comes on, so if it's
> the motor you'll probably want to do something about it soon.
>
> What are the options to add cooling?
>
> Regards
>
> [Technik] James
>




------------------------------------

Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/electricboats/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/electricboats/join
    (Yahoo! ID required)

<*> To change settings via email:
    electricboats-digest@yahoogroups.com
    electricboats-fullfeatured@yahoogroups.com

<*> To unsubscribe from this group, send an email to:
    electricboats-unsubscribe@yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/


 

__._,_.___
Recent Activity:
.

__,_._,___

[Electric Boats] Re: Ramblings about electric versus ICE (slightly OT)

 


Cant help thinking that three transformers and a three phase rectifier with a 3 phase generator would be an answer to this .

Chris S

--- In electricboats@yahoogroups.com, James Sizemore <james@...> wrote:
>
.................... Someone needs to design a high current 48 volt to 144 volt rectifier.

__._,_.___
Recent Activity:
MARKETPLACE

Stay on top of your group activity without leaving the page you're on - Get the Yahoo! Toolbar now.


Get great advice about dogs and cats. Visit the Dog & Cat Answers Center.


Hobbies & Activities Zone: Find others who share your passions! Explore new interests.

.

__,_._,___

Saturday, May 29, 2010

Re: [Electric Boats] Safety weekend

 

It's the controller - and yes it just starts ramping down the amperage to cool off, but that can happen at inopportune times. I added a fan today and that helps - I've got a Sevcon PMAC mounted on 3/8 alum plate which in turn has a heatsink - all connected with that gooey thermal grease. I have a spot infrared sensor and it was showing about 200F on the face of the controller when it went into shutdown.

I think the 'sensor' on my motor overheating is molten copper being thrown about ;) (it's the Mars brushless)

And BTW...it wasn't all seriousness today - after I got some good work done I went out and had one of the best sails I've had in months! T-shirt & shorts in 15kts steady (a far cry from last weekend)

-K

--- In electricboats@yahoogroups.com, James Massey <jcmassey@...> wrote:
>
> G'day Keith, All
>
> At 04:02 AM 30/05/2010, Keith wrote:
> >We've lost 3 good sailors here in CA recently, so I'm spending the
> >weekend upgrading my safety profile. <snip>
> >I still can't sustain > 60amps without overheating, so that's a concern.
>
> Which component/components can't sustain 60 amps? I'd assume only the
> controller or motor could overheat and tell you (anything else would
> just melt down and stop)?
>
> Care to give a basic system description, or do you already have it in
> hand? (If you have it in hand already, please describe your mods).
>
> A controller usually just goes into a shut-down mode, but motors are
> often suffering by the time their thermal switch comes on, so if it's
> the motor you'll probably want to do something about it soon.
>
> What are the options to add cooling?
>
> Regards
>
> [Technik] James
>

__._,_.___
Recent Activity:
MARKETPLACE

Stay on top of your group activity without leaving the page you're on - Get the Yahoo! Toolbar now.


Get great advice about dogs and cats. Visit the Dog & Cat Answers Center.


Hobbies & Activities Zone: Find others who share your passions! Explore new interests.

.

__,_._,___

Re: [Electric Boats] Safety weekend

 

G'day Keith, All

At 04:02 AM 30/05/2010, Keith wrote:
>We've lost 3 good sailors here in CA recently, so I'm spending the
>weekend upgrading my safety profile. <snip>
>I still can't sustain > 60amps without overheating, so that's a concern.

Which component/components can't sustain 60 amps? I'd assume only the
controller or motor could overheat and tell you (anything else would
just melt down and stop)?

Care to give a basic system description, or do you already have it in
hand? (If you have it in hand already, please describe your mods).

A controller usually just goes into a shut-down mode, but motors are
often suffering by the time their thermal switch comes on, so if it's
the motor you'll probably want to do something about it soon.

What are the options to add cooling?

Regards

[Technik] James

__._,_.___
Recent Activity:
.

__,_._,___

[Electric Boats] On-line education?

 

My guess is that there are many folks following this group who are like me and cannot find continuing education courses (especially on-line) to learn more of the operational details of electric propulsion. Books that I have read have gotten me a start but come up short in helping me gain the knowledge that I want to have as a DIY'er.

If there are indeed those kind of on-line resources, I would appreciate any help locating them. If not, it would seem that a group such as Mark Stafford's Green Marine Re-Power foundation would be an excellent place from which to offer courses (for a fee) that could be developed by the industry leaders of electric boating. And in the end, an education/certification process would also help to promote quality design and implementation as well as safety for our new industry.

__._,_.___
Recent Activity:
.

__,_._,___