RUNNING ELECTRIC MOTORS & SERVOS WET

[subdog]

[color=#000000]I'm a newbie with subs. 2 questions please]

[thesubdude]

No, you can't run motors

No, you can't run motors or servos wet. In rc subs is a compartment called a wtc(water tight cylinder) to keep electronics and running gear dry. These cost around $100 and up or you can build one with a pvc pipe as shown by Jim Butt http://www.rc-submarines.com/id60.htm. All the rc components including motors and servos are mounted in the wtc. This does make the sub more boyant, but this is corrected by leveling the sub to the correct waterline by small weights.



Hope this helps, Erik

[Guest]

You can run motors in

You can run motors in the wet (provided you are running in fresh water), but they will wear out faster.

Some folk have succesfully run servos in the wet by carying out various waterproofing procedures. I'm not a big fan of this practice to be honest.

If you want a boat to run deep and remain watertight, then a cylinder is the second best shape (second only to a sphere).

Servos tend to be box shaped, which makes them far more prone to flexing and hence leakage at large depths.

For small depths this isn't a big deal, so you decide what's right for you.

Andy

[chuck chesney]

I agree with Sub Culture

I agree with Sub Culture 100%. Some people do run dirve motors wet, but it shortens the life of the motors by quite a lot. Servos are a different matter, and I've never heard of a servo running properly for very long when it's being run wet, regardless of whatever is done to make the electronics waterproof.
A WTC is going to provide a much more satisfactory way to run the drive motors and servos. The initial cost is slightly more than running components wet, but the payoff is in extended component life, higher reliability and the peace of mind of not having to worry about when the wet components are going to fail.

[subdog]

Thanks for help. I appreciate

Thanks for help. I appreciate the advice. Has anyone out there run the motors wet or servos wet before??

[bobco]

I just changed over this

I just changed over this summer to a wet motor with no problems and one less hull through connection to worry about...particularly a rotating shaft through a seal! The way I and many look at it is this...the motor won't last as long but it's 4 bucks! Of course there is the danger of it failing at most inopportune time (rc sub murphy's law) but nevertheless when it's toast just swap it out.

video here (click on Permit video)..

http://www.bcliffe.com/subs/Submarines.html

Bob Cowan

[tmsmalley]

SD -
Jeff Jones who posts

SD -
Jeff Jones who posts here from time to time has had pretty good luck with wet servos. I believe he opens them up and fills them up with Vaseline. Then he press fits an O-ring over the shaft where it exits the housing. Seems to me he'd get a couple of years out of them before they needed to be replaced.

Worth a shot anyway - servos are cheap!

There used to be a product called "The Stuph" that you could use to waterproof danged near anything. Ships N' Things used to sell it but I'm not sure if it's available anymore.

[anonymous]

I know servos are cheap,

I know servos are cheap, and I was inspired by that previous thread on waterproofing servos. So I tried it and it worked - I think!!

The problem is you never know if water has got into the servo case and you are sort of waiting for it to fail. Call me fussy but I didn't like it

I would consider it for operating some purely decorative function (I was looking to raise a periscope mast hydraulically) but I would not use it for planes, rudder etc.

David

[raalst]

hi,

just for fun, here

hi,

just for fun, here is the remains of my kilo motor after
about one and a half year of service.
main reason for replacement was that it seemed not so
powerful any more, but it was still running.
later on, it turned out that the corroded electrical terminals
were probably a large factor, not the state of the motor.

the axle


the housing. note that these motors do not have ball bearings but bushings. I think this might be an advantage when running wet.


the brushes


source of my motors are 12 volt car locks, I run them on 6 penlites (7.2 volts)




Edited By raalst on 1158954096

[subdog]

Is the motor shown a

Is the motor shown a "brushless" one? Does that make a difference brushless over one with brushes if you run it wet?

[raalst]

second photo shows the *brushes*

second photo shows the *brushes*

so that disqualifies as a brushless motor.
The black thing in the last picture is the car door lock
which houses this type of electric motor.



Edited By raalst on 1159015817

[subdog]

So the ones in the

So the ones in the picture have brushes and you ran them in the car lock housing for 1 year and a half? Did the housing completely seal the motor or was it running somewhat "wet"?

Did you use any sealant or protective type lubricant?



Edited By SUBDOG on 1159070495

[raalst]

No, the car locks is

No, the car locks is where I get them out of. I break the casing and take out the motor, then put that motor in my boat, in the wet section. I use car locks because these things will be available still when I need another replecement. If you plan for replacements, you better ensure that you can get identical ones still when the replacement is due.

have a quick look at my Kilo photo's
at my homepage
and this
in particular. not a wtc in sight . You do a trumpeter conversion as well ?

for preps, I blew a bit of WD40 into the motor. thats silicone spray. nothing fancy...

in that one and a half years I ran it about 6 times, twice in a chlorinated pool (chlorinated water corrodes more than your average pond).
I feel that rinsing with tapwater would have improved the
lifespan of the motor even more.

[subdog]

No, the car locks is

No, the car locks is where I get them out of. I break the casing and take out the motor, then put that motor in my boat, in the wet section. I use car locks because these things will be available still when I need another replecement. If you plan for replacements, you better ensure that you can get identical ones still when the replacement is due.

have a quick look at my Kilo photo's
at my homepage
and this
in particular. not a wtc in sight . You do a trumpeter conversion as well ?

for preps, I blew a bit of WD40 into the motor. thats silicone spray. nothing fancy...

in that one and a half years I ran it about 6 times, twice in a chlorinated pool (chlorinated water corrodes more than your average pond).
I feel that rinsing with tapwater would have improved the
lifespan of the motor even more.

Thanks for the info. So far, I've coated my servos and my electric motor with "corrosion x" and will run them wet in my Kilo. The receiver and connections I'm siliconing with GE Silicone II, RTV.
Corrosion X claims you can coat the inside of a TV with it, place it in the water and run the TV. We shall see....If this works, this may be an alternative to the WTC.