[PSUBS-MAILIST] Brushless Thrusters
via Personal_Submersibles
personal_submersibles at psubs.org
Tue Sep 9 08:34:23 EDT 2014
Hank,
Those JSL thrusters draw something like 30 amps or a little better at 28 volts, so Ed Link was much of the same mind about these things. He did not like high voltage in seawater. Period.
Vance
-----Original Message-----
From: hank pronk via Personal_Submersibles <personal_submersibles at psubs.org>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Sent: Tue, Sep 9, 2014 8:03 am
Subject: Re: [PSUBS-MAILIST] Brushless Thrusters
Alan,
Got it, I do remember that the thrusters on DW's are pretty small for the
output. I am surprised that they are more efficient though. I would guess the
efficiency comes from voltage and lack of line loss. I am so out of date. I
like a big motor and don't work it hard and run huge power leads to it.
Hank --------------------------------------------
On Tue, 9/9/14, Alan via Personal_Submersibles <personal_submersibles at psubs.org>
wrote:
Subject: Re: [PSUBS-MAILIST] Brushless Thrusters
To: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>
Received: Tuesday, September 9, 2014, 2:48 AM
Hank,
all
the big boys are using them.
They are more
efficient, & power to size ratio is high. That one I
posted a link to
is 1&1/2" diameter
x 3" long & 1200W, & $30-. There would be a lot
less motor
to get in the way of the kort
nozzle intake.
As to motor cooling. From
what I have read it is a big issue & overheating causes
most motor failures. Motors like Minnkota & probably
your motor are purpose built with thicker windings designed
to handle the extra heat building up inside an enclosed
unit.
If I am home building & picking a
brushed motor off the shelf I might be hard pressed to
find
one suitable & probably
wouldn't recognize it anyway. I could always oil
compensate
as a means of cooling. However
the in- runner brushless have (as said previously) the
coils on the outside, so heat generated is
conducted straight through the can to the
water rather than through air first as in an
out-runner brushless or brushed DC motor.
Motors are rated on efficiency, & if you
have an 80 % efficiency on a 1000W motor
you
have a 200W heater inside your thruster can.
I am pretty sure the
professionally made brushless thrusters would be made by
sourcing
existing motors, motor controllers,
planetary gear boxes & shaft seals, & making a can
to fit them in.
It's just a matter of
tracking these items down. ( which is a pain)
Regards Alan
Sent from my
iPad
> On 9/09/2014, at
11:56 am, hank pronk via Personal_Submersibles <personal_submersibles at psubs.org>
wrote:
>
>
> Alan,
> I am wondering
why your so interested in brushless motors. What am I
missing, also there has been discussions about heat, what
heat? A motor in water, what could be better :-) After a
3km run in gamma, my motor is maybe Luke warm at best.
> Hank
--------------------------------------------
> On Tue, 9/9/14, Alan via
Personal_Submersibles <personal_submersibles at psubs.org>
wrote:
>
> Subject:
Re: [PSUBS-MAILIST] Brushless Thrusters
>
To: "Personal Submersibles General Discussion"
<personal_submersibles at psubs.org>
> Received: Tuesday, September 9, 2014,
12:35 AM
>
>
Update,Am still Googling away
> in
pursuit of a home made brushless thruster.I am set on using
an in-runner motor as they have
> the
coils on the outside & will be ableto transfer heat
through the can.The problem with in-runners is they have
higher
> revs than out-runners, however
either will require a planetary gearbox. I am looking at
> reducing the revs down to below 3000 rpm.
This is based on other brushless thrusters I have
> looked at but might not be right ( any
> recommendations)?Another problem is
that
> most seem to draw huge amps.Here
is a
> 1200W motor for $30-. Of course
there is the price of the
> controller
& planetary gear that are
>
needed.http://www.hobbyking.co.uk/mobile/viewproduct.asp?idproduct=17720&type=&idparentcat=364Most
of the suitable motors seem to be found at
> places like Hobby King, and are used on RC
trucks, or found
> on E bike sights. The
aircraft motors aren't as
>
robust.These motors are tiny, but
>
hugely powerful, so there is the potential to make a
small
> streamlinedpowerful unit.I
haven't had much luck with a matching
> gearbox. Some of the planetary gearboxes
recommendoiling (no good to me unless I oil compensate)
> while others don't. I am looking for a
cylindrical unit
> to match my motor,
preferably with thrust
> bearings.If
anyones got any advice or
> experience in
this realm I'd be pleased to hear
>
it.Regards Alan
>
>
Sent from
> my iPad
>
On
> 7/09/2014, at 8:43 pm, Alan via
Personal_Submersibles <personal_submersibles at psubs.org>
> wrote:
>
> Hi Hank,the kort
>
nozzle on the Indonesian thruster looks a bit
> Naff. ( I am designing an art work
> here.)I could get a price for the unit
without
> kort nozzle, butI'm
wondering if I could
> build something
for 1/2 that price.There are some
>
reasonably priced brushless motors about.I
> don't know that I could just retro fit
a thrust bearing
> inside the can of the
motor.I tried to put a
> thrust bearing
for reverse inside my brushed thrusters,
> butcouldn't find one with a thin
enough
> section to fit.Also the motors
are a bit
> expensive to just buy &
hope you can fit
> one.How did you fit
the thrust bearing on Gamma?
> Did the
propellor shaft extend out the backof
>
the motor?Alan
>
>
Sent from my iPad
> On
> 7/09/2014, at 7:22 pm, hank pronk via
Personal_Submersibles
> <personal_submersibles at psubs.org>
> wrote:
>
> Allan
> Dont worry
about
> thrust bearings to much. They
are aesy to get, I bought one
> for Gamma
, real heavy duty for 80 dollars. Personally I
> would just use a good quality bearing and
replace it once a
> year for 8 bucks, if
it is a small thruster. Are you not
> happy with the Indonesia thrusters? Or
to pricey?
> Hank
>
>
>
>
>
>
>
>
>
From:
>
>
Alan via Personal_Submersibles
> <personal_submersibles at psubs.org>;
>
>
>
>
To:
>
>
Personal Submersibles
General
> Discussion <personal_submersibles at psubs.org>;
>
>
>
>
>
Subject:
>
>
[PSUBS-MAILIST] Brushless
>
Thrusters
>
>
>
Sent:
>
>
Sun, Sep 7, 2014 11:58:56 AM
>
>
>
>
>
>
Hi people,
> I've
> spent
several hours today looking at brushless thrusters
> & wonder if anyone else has looked at
them or got any
> ideas. There is the
Indonesian thruster I posted a few weeks
> back at US 2,200. There is also the
Haswing Protruar 2hp
> that Emile has;
however they state that it's for fresh
> water only, & I think Emile said it
was a bit noisy.
> The inrunner motors
that have the winding on
> the outside,
seem a good option as they cool through
>
convection to the can. They also need higher revs for
torque
> & require a planetary gear
box or similar. ( which a lot
> have
built in)
> I was looking at the
> option of making my own thruster, however
the motor would
> require a thrust
bearing & I don't
> know of any
that would have one other than
> maybe a
high powered battery operated drill.
>
Any thoughts, suggestions thanks.
>
Alan
>
> Sent from
> my
> iPad
>
_______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
>
>
>
_______________________________________________
> Personal_Submersibles mailing
> list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
_______________________________________________
> Personal_Submersibles mailing
> list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
> -----Inline
Attachment Follows-----
>
>
_______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
>
_______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20140909/adef28fe/attachment-0001.html>
More information about the Personal_Submersibles
mailing list