Marine electric propeller motors
David MacKinnon
With a propeller and proper housing?
What are the top speeds of such motors?
Any information would greatly be appreciated
David
Roberto Waltman
How difficult is it to type "marine electric motors" in
Google's home page and then click on "search" ?
Roberto. Waltman
Terry King
bad.address....@bellatlantic.net says...
application. Hobby boat size? Fishing boat?
--
Regards, Terry King ...In The Woods In Vermont
tk...@waitsriver.k12.vt.us
David MacKinnon
from people who might
of used them. To get some 'out of the box' ideas. I wasn't hoping to get
smart ass comments from people like you.
Isn't it possible to have a newsgroup without these waste-of-time messages.
Now I'm guilty of doing it. Serenity now!!
"Roberto Waltman" <bad.address....@bellatlantic.net> wrote in
message news:b748su8dbg4uhb8e9...@4ax.com...
David MacKinnon
http://www.videoray.com/Products/products_intro.htm
... without the $12K price tag.
I wonder if it's possible to get 3 knots with an embilical cord?
Let's say at a depth of 150 ft.
I'm just brainstorming for the moment. It would be awhile before
I get serious.
"Terry King" <tk...@waitsriver.k12.vt.us> wrote in message
news:MPG.182e008b7...@news.k12.vt.us...
David Hepworth
Commercial ones are Sooo expensive but try doing a search on Hobby ROV
There are some good ideas for home build.
Problem is keeping the water out at depth (1 bar for every 10 metres !!!)
If anyone can come up with a source of cheap ready built units I will be
very interested myself
Good luck.
"David MacKinnon" <dmki...@hotmail.com> wrote in message
news:kXSw9.573$wy.4...@ursa-nb00s0.nbnet.nb.ca...
Blueeyedpop
Try typing "serenity now" into google for more answers.
Personally, I like seeing what people are interested in, and typing your
request into the "google" isn't sharing with anyone.
Also, by your asking here, you give the opportunity for people to spew what
they know.
I have not seen puropse built electric submersable motors.
"David MacKinnon" <dmki...@hotmail.com> wrote in message
news:uJWw9.656$wy.6...@ursa-nb00s0.nbnet.nb.ca...
Um,
Try typing "serenity now" into google for more answers.
Personally, I like seeing what people are interested in, and typing your
request into the "google" isn't sharing with anyone.
Also, by your asking here, you give the opportunity for people to spew what
they know.
I have not seen puropse built electric submersable motors off the shelf, but
hobby stores often carry miniature props etc. At 150 feet beow the surface,
your challenge is going to be keeping the water out I would imagine.
Blueeyedpop
"dan michaels" <d...@oricomtech.com> wrote in message
news:4b4b6093.02110...@posting.google.com...
> "Blueeyedpop" <bluee...@sbcglobal.net> wrote in message
news:<jsYw9.4944$L26....@newssvr16.news.prodigy.com>...
> .............
> > Um,
> > Try typing "serenity now" into google for more answers.
> > Personally, I like seeing what people are interested in, and typing your
> > request into the "google" isn't sharing with anyone.
> > Also, by your asking here, you give the opportunity for people to spew
what
> > they know.
>
>
> B.pop, you must be a philosopher. I took your advice, and got here:
>
> http://www.hazeldenbookplace.org/serenitynow/index.asp
>
> The one on tolerance looked good, so I clicked there and eventually
> got to here:
>
>
http://www.hazeldenbookplace.org/serenitynow/detail.asp?meid=695&fid=74&cid=
81
>
> There I learned that: "Conceit is God's gift to little men".
>
> Cool. :) It's almost as good as my favorite: "Egotism is the
> anesthetic that dulls the pain of stupidity"
To me, the newsgroups are a great place to share ideas. Sure, we could all
"google up" our answers( I like using Google as a verb), but I haven't
published all of my opinions and ideas on the web, and so, for now, google
can't access my thoughts(yet). Who knows what sort of a spark a question can
be.
Mike
Mitch Berkson
> What you need are ROV thrusters (Remotely Operated Vehicles).
> Commercial ones are Sooo expensive but try doing a search on Hobby ROV
> There are some good ideas for home build.
> Problem is keeping the water out at depth (1 bar for every 10 metres
> !!!) If anyone can come up with a source of cheap ready built units I
> will be very interested myself
> Good luck.
The ones offered by the company of the ROV the OP wants to duplicate don't
seem exorbitant at $120 considering that they've already been tested for
this application.
Mitch Berkson
Ford Prefect
of companies that marine motors that way, narrowing it is down is terribly
difficult for someone who doesn't know anything about the companies... not
everyone is all knowing like you.
"Roberto Waltman" <bad.address....@bellatlantic.net> wrote in
message news:b748su8dbg4uhb8e9...@4ax.com...
Mitch Berkson
> Hey wMan, how hard is it to type in a helpful answer? You'll find
> hundreds of companies that marine motors that way, narrowing it is
> down is terribly difficult for someone who doesn't know anything
> about the companies... not everyone is all knowing like you.
Please. The OP didn't even allude to the use to which he planned to put the
"marine electric motors". For all anyone knew he wanted to build his own
jet ski. Once he provided the additional information about the Videoray
ROV, it became a question worth answering, but you only know that in
hindsight. At the time of the original inquiry, a pointer to Google seemed
perfectly reasonable.
Mitch Berkson
Grog
> Essentially I would like to design one of these...
> http://www.videoray.com/Products/products_intro.htm
> ... without the $12K price tag.
>
> I wonder if it's possible to get 3 knots with an embilical cord?
> Let's say at a depth of 150 ft.
>
> I'm just brainstorming for the moment. It would be awhile before
> I get serious.
>
You'll be wanting one of these then:
http://www.titanrov.com/commodore.htm
Greg the Grog
@baesystems.com Tim Jacobs
news:4rXw9.2284$%q2.8...@newsfep1-win.server.ntli.net...
> Problem is keeping the water out at depth (1 bar for every 10 metres !!!)
My latest cunning plan is not to try to keep the water out at all. A
purpose-built (i.e. waterproof parts) brushless motor should be able to run
in water. The water may even help to cool it. I've got some parts built
based on a home made model aircraft motor design, I just need to get it
working in air, then dump it into water and see if it works.
http://www.soton.ac.uk/~suleiman/research/reports/electricthruster.pdf
This is a brushless thruster for work-class ROVs.
HTH
Tim
--
These are my views, not those of my employer.
Mitch Berkson
> My latest cunning plan is not to try to keep the water out at all.
>
> http://www.soton.ac.uk/~suleiman/research/reports/electricthruster.pdf
>
> This is a brushless thruster for work-class ROVs.
With the rotor/stator gap open, I wonder if there are magnetic particles in
the water (e.g., the magnetite found on some beaches) which will pile up on
the magnets and cause trouble.
Mitch Berkson
Mark Moulding
appears that these folks have constructed a 2 inch long, 10 inch diameter
motor which, while converting *eight horsepower* of electricity to
mechanical power is achieving a thrust of up to 220 pounds and up to 5 MPH.\
That's a lot of power in a little volume! (Please forgive the journey into
medieval measurements...)
--
Mark Moulding
"I prefer heaven for climate, and hell for companionship."
"Tim Jacobs" <timothy.jacobs @baesystems.com> wrote in message
news:3dc7...@baen1673807.greenlnk.net...
Terry King
ma...@markesystems.com says...
> My latest cunning plan is not to try to keep the water out at all. A
> > purpose-built (i.e. waterproof parts) brushless motor should be able to
> run
> > in water. The water may even help to cool it.
>
was enclosed in a very thin stainless steel shell and immersed in the
water. But I'm pretty sure they're not rated for SALT water...
@baesystems.com Tim Jacobs
> In article <nIWx9.231$dc1.21...@newssvr13.news.prodigy.com>,
> ma...@markesystems.com says...
> > My latest cunning plan is not to try to keep the water out at all. A
> > > purpose-built (i.e. waterproof parts) brushless motor should be able
to
> > run
> > > in water. The water may even help to cool it.
> >
> Is this SALT water?? I've seen small pumps where the induction armature
> was enclosed in a very thin stainless steel shell and immersed in the
> water. But I'm pretty sure they're not rated for SALT water...
Why use metal? What's wrong with plastics? Or even paint?
The point is that there doesn't need to be any exposed electrical contacts
in a brushless motor. Therefore, you don't _need_ to keep the water out.
@baesystems.com Tim Jacobs
news:aZOx9.91262$vq2.3...@news1.east.cox.net...
Hmmm. How about putting magnets around the bearings to act in a similar
manner to a sacrificial anode?
Or just clean the rotor regularly.
Dave Hepworth
Mitch
$120 is just for the motor.
You also need Housing, Seals & Prop. Probably more like $500+ all in.
These motors are not usually submersible - just too unreliable with
all the crud thats hanging about in seawater so the seals are pretty
complex and therefore expensive.
I have heard of some success filling the motor casing with oil (bit
messy though).
Also with submersible motors you can have a big problem with the
bearings !
Best bet might be an on-board motor with a prop-shaft through a
stuffing box and guide vanes to direct i.e. A Torpedo
Dave
Alan Hooker
motor.
Why? No pressure differential problems. No seal problems, no lubrication
problems.
How. The idea is to return the oil from the motor to a small 'tank'
(maybe a litre or so).
This also becomes the supply point to the pump.
The trick is to keep this return / storage tank at the sea depth
pressure by incorporating a rubber diaphragm in one side.
Therefore the pump and motor now behave as if at atmospheric pressure,
regardless of depth.
Speed control can be by either direct control of pump speed (most
efficient?) or by using a constant speed pump with a hydraulic 5 way (I
think) valve to control the flow (+ relief valve to bleed flow at low
speeds).
Don't like using oil? There are water soluble oil solutions. I think
glycol is a possibility also.
In reflection, pump speed control seems most sensible, UNLESS you want
to control lots of devices (thrusters, robot arms, camera pan/tilts. In
that case, things change. How about pressure control of the oil, so the
pump varies its output on demand?
The 5 way solution with constant speed pump above is used on some
commercial ROVs.
In know this is a long way from nice simple electric thrusters, but I
have a feeling that electric may not be quite as nice & easy as you
might think
Alan Hooker
______________________________________________________________________________________
@baesystems.com Tim Jacobs
news:3DC97B6E...@itnz.co.nz...
> Another choice for underwater motive power is to use a small hydraulic
> motor.
<Snip>
> Don't like using oil? There are water soluble oil solutions. I think
> glycol is a possibility also.
Why not use water?
Some of the "hobby ROVs" I've seen on the web use submersible bilge pumps as
thrusters. These are a lot cheaper than sealing motors, even if you have to
use 2 pumps to do the job of 1 reversible motor. The limiting factor here
is the depth tolerance of the pumps.
Another idea I've seen involves using 1 large water pump with valves to
direct the water to nozzles around the ROV. Though I should think this
would cause headaches getting the thrust balance right.
Paul Britton
"Mark Moulding" <ma...@markesystems.com> wrote in message
news:nIWx9.231$dc1.21...@newssvr13.news.prodigy.com...
> Wow. After using my thumb to convert to English units (very roughly), it
> appears that these folks have constructed a 2 inch long, 10 inch diameter
> motor which, while converting *eight horsepower* of electricity to
> mechanical power is achieving a thrust of up to 220 pounds and up to 5
MPH.\
>
> That's a lot of power in a little volume! (Please forgive the journey
into
> medieval measurements...)
I'm not sure about the predicted 1000N @5.5kW, if you look at the graph,
only the points upto 2.5kW are actual measured data, those above are 'power
law estimates', but the extrapolated line doesn't seem to fit the measured
data very well, it looks to me like the curve is flattening out to a limit
of around 500N.
But hey I'm not a real scientist, so I could be wrong, I only have the
evidence to go on!!
PaulB