Homebuilt ROVs Forum

I would be interested in seeing what a brushed motor does in seawater, maybe you could see how long they last in that or if they work at all.

If you wanted to try and don't live near any seawater just dissolve about 3 teaspoons salt in 2 cups of water.

Anyway, just a though. Nice work on the oil bath though, good research there.

I might just try that
Getting seawater is no problem.

Also, I read somewhere that "babyoil" might be better (at least for electronics in general). So will try that also when I get time
And as other users here have used for their electronics, silicon oil, but I cant find anywhere to buy that stuff here.

Okey, this is kinda hilarious.
I found a shop selling clear silicon oil. They sell 1L and 5L bottles and the quote I got for 1L (0.26gal) was 350 euros.. plus shipping. Pretty pricey stuff.

Silicon oil is comely used in treadmills, found some on Amazon for pretty cheap if you did want to try it.

http://www.amazon.com/G-MAX-Treadmill-L ... B009T1L34S

That was a much more reasonable price! Yet I am hoping to find something locally. But if I don't I will have to order online somewhere.

Small update.

Found some really cheap clear mineral oil at IKEA called "SKYDD". It is used for treating wood furniture and comes in 0.5l bottles.

So I filled a glass with oil and submerged a motor in. This time I let it sit for a while, and did what I could to shake all the air out from the motor.
Also I am only running the motor at 5v this time. I do suspect that they really can't handle the 12v they are rated for over a longer time.

It has now been sitting in oil for 3 days and running on 5v for 6-7 hours on two of the days. So a total of 12-14 hours of running in the oil.
So far I can't observe no change what so ever. The motors sounds the same as when I first started and there is no residue in the oil.
So this looks much more promising

Attached a picture of the motor submerged in oil. There is a printed gear glued to the shaft of this motor.

Update:

Eventually this motor also stopped turning. I don't exactly know when it happened, but some time during day number 4.

I opened the motor (had to really force it open) and discovered that these don't really have brushes, but just some copper/brass "arms" that contacts the rotor (?).
It seems that one of the arms has been forced over to the wrong side of the rotor. Maybe the oil ads friction?
There were no sign of wear at all other then the bent arm.

Pretty interesting, thanks for reporting your tests.