Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Submarines => Topic started by: Goingdown on September 30, 2009, 12:48:32 pm

Title: Running motors "wet"
Post by: Goingdown on September 30, 2009, 12:48:32 pm
Ahoy there,

Firstly, greetings to all the members from a new poster.    I have read that it is possible to run electric motors in fresh water wet - do any of you do this in your submarines or are there some darw backs that I am not aware of.   I suspect one would be don't run it in salt water!

Regards

Goingdown
Title: Re: Running motors "wet"
Post by: Martin (Admin) on September 30, 2009, 01:07:46 pm

I heard this possibility but having experienced getting motors wet.... unintentionally  in leaky boats, corrosion quickly set in,
I guess from electrolysis , heat and impurities in the water.
Title: Re: Running motors "wet"
Post by: snowwolflair on September 30, 2009, 01:18:21 pm
Brushless will be far more tollerant than brushed motors due to the coils being sealed and there being nothing electrical to corrode.  I would still use WD40 before and after each use.
Title: Re: Running motors "wet"
Post by: Tester on September 30, 2009, 02:03:03 pm
Hi

Are you talking about running in electric motors underwater for a couple of minutes, I've done that but I wouldn't run one permanently underwater.

This may be causing some confusion

Richard

PS Welcome to the board
Title: Re: Running motors "wet"
Post by: sheerline on September 30, 2009, 02:25:31 pm
The armature core is mild steel and the permanent magnet is iron, both rust badly, swell up and jam the motor solid when it's layed up. The commutator is made from copper, it goes black and becomes intermittent and even if you get the motor going again, it sparks heavily and causes high levels of static. You can't use WD40 to prevent any of this damage on brushed motors as it destroys the brushes and clogs the the commutator with carbon.
All in all, not a good idea methinks.
Title: Re: Running motors "wet"
Post by: snowwolflair on September 30, 2009, 03:33:05 pm
Quote
You can't use WD40 to prevent any of this damage on brushed motors as it destroys the brushes and clogs the the commutator with carbon.

If you go back and read my post again you will see my comment on WD40 was for brushless.

You shouldn't even think of trying brushed motors under water, or WD40 near them in or out of water.
Title: Re: Running motors "wet"
Post by: HS93 (RIP) on September 30, 2009, 03:57:43 pm
year ago when I did 12th scale cars people would run motors in in a glass of water, about 15 seconds was enough 40 seconds and no brushes left , it was when motors where sealed and before open brushes that can be altered and put back in . so if you want to change motors every 2 min OK wd 40 on brushgear burns and forms a coating that does not help good motor running,
well thats my thoughts.

Peter
Title: Re: Running motors "wet"
Post by: raalst on September 30, 2009, 05:35:38 pm
I have good results running cheap motors (without Ball bearings)
in the wet in a Trumpeter Kilo.
the motor tends to last about 1,5 years.

I use motors from electric car door locks. I suppose these are intended to be operated in
damp conditions. 12 volts but my 6 penlites kick it along rather well.

Running the motor in the wet eliminates one difficult seal, and enables you to make better use of the
sub's tail. plus it saves a lot of space in the dry compartment.

a few photo's of my boats' construction : http://www.modelbouwforum.nl/forums/duikboten/80893-de-kilo-er-weer-versie-iii.html#post1218123 (http://www.modelbouwforum.nl/forums/duikboten/80893-de-kilo-er-weer-versie-iii.html#post1218123)

some video here : http://www.vimeo.com/5152968 (http://www.vimeo.com/5152968)

all I can say is : try it!
Title: Re: Running motors "wet"
Post by: Turbulent on September 30, 2009, 06:55:20 pm
Paul cook ran 2 400 motors wet in a sub a couple of years ago with reasonable success, I run my Gato with motors in cases packed with grease, but not sure I'd risk having them naked in the wet
Title: Re: Running motors "wet"
Post by: raalst on September 30, 2009, 08:45:59 pm
I forgot to mention :
be sure the motors are
- easily replaceable in your model
- still available in 1,5 years time

mine is strapped to the boat with a tie-wrap. the
connection to the prop axle is with a bit of
silicone (fuel-)tubing.
Title: Re: Running motors "wet"
Post by: HS93 (RIP) on September 30, 2009, 11:05:12 pm
My reply should have read "years ago" some model shops even sold them as water dipped, they where the 05 type motor,one problem we found when opening winning motors was that they had rusted even though some had been cleaned in tryce after (later banned at races).. get one and try it look at the black in the water after a few seconds..

Peter
Title: Re: Running motors "wet"
Post by: HS93 (RIP) on October 01, 2009, 12:26:13 am
A couple of articles on water dipping motors.

http://www.rccartips.com/rc-electric-motor-tuning-guide.htm

http://www.rcboataholic.com/motors/motor%20breakin.htm

http://www.hobbyworks.com/default.cfm/Content/fullarticle/hs/rc/ID/21

Peter