Why run motor in water?

[stuka]

Heard dc motor may be run completely submerged in water, has anyone tried? What are the benefits of doing so? Will it last longer because it gets maximum cooling running in water? Why is the batt not short-circuited since water is also a conductor?

Thanks for help

[Artyspec]

yep, i tried. i took one of those cheapo 3v tamiya motors and ran it under water. it works. not shortage. This method is for running in motors. But you cant use it for boats cuz when you flood your motor, those "fins" in your motor will hit the water and create alot of drag. But if you ignore this fact, it is actually alright.(i think) Do you need a picture of my motor running in water?

[victor]

I tried dis wif my tamiya once too, in a swimming pool...it was running on the bottom of the pool...just worried dat the shaft might rust or something...

victor

[mechplas]

From Ezone.


This is an alternative way of breaking in a can motor by running it at least partly underwater (at the low voltages used this is not at all dangerous). Doing it this way takes only a few minutes so is a lot quicker than the traditional way of running the motor dry for several hours. There are a number of different ways of doing a water break-in. All seem to work. It's up to you which you prefer. All versions have in common the fact that the new motor is run with no load and immersed in water. The break-in is complete when you see the water go slightly gray or hear the motor speed up.

The main variations are :
The water can be tap water or distilled water.
You can optionally add a VERY SMALL amount of dish washing liquid to the water
The motor can be run on normal voltage, on one cell less than normal, on 2 alkaline cells or on a low voltage from a power supply (I have used 5V)
Some motors have very hard brushes and will never bed in properly however long you leave them. If you see/hear no results within 10 minutes you may as well give up.

When you have finished, dry the motor carefully. A hairdryer on a low setting works well. Then lubricate the bearings with a couple of drops of thin oil and you're ready to go.

[mechplas]

http://www.ezonemag.com/pages/efaq.htm#motor1

This is a very good readup...theory only no colour picture

[Simys]

For sure there is a current leakage in the water, but it won't cause the motor to be malfunction. If you place the ESC in the water, then you can say bye-bye to your ESC as the water will create a short to the IC chips.

Why people wants to place their motor in the water?
This will only happen when the first time the motor is in use. The contact surface is not smooth and the running motor will create a lot of minute debris. The main purpose to submerge the motor in water is to remove those debris during the burn-in while the motor is running...something likes 1 stone kills 2 birds. After the burn-in, the motor contact should be smooth.

Remember not to put your finger in the water when you do the burn-in test or else....

[civic3106]

For sure there is a current leakage in the water, but it won't cause the motor to be malfunction. If you place the ESC in the water, then you can say bye-bye to your ESC as the water will create a short to the IC chips.

Why people wants to place their motor in the water?
This will only happen when the first time the motor is in use. The contact surface is not smooth and the running motor will create a lot of minute debris. The main purpose to submerge the motor in water is to remove those debris during the burn-in while the motor is running...something likes 1 stone kills 2 birds. After the burn-in, the motor contact should be smooth.

Remember not to put your finger in the water when you do the burn-in test or else....

Some industry uses Shell Tellus 32 for their oil filled motor (especially subsea motors). Think this will be a better option for run-in rather than using water.

[stuka]

Thanks guys, what will happen if I just use the motor without running in, will that shorten its lifespan?

The reason I asked is actually not for running in but for powering a vessel underwater. I am contemplating whether to install the motor inside a watertight container (WTC) togther with ESC or outside it in a completely flooded compartment so that I dont have to direct water into WTC for cooling the motor. Looks like I better keep it inside WTC...

Loyn, r u keeping the twin motors of your fish outside WTC?

[lu wei yao]

Hi there! Not sure if it has been said, but the purpose of running a motor in water is to wear out the brushes evenly to improve efficiency and performance. its a proven process that works well. Change the water onece in a while and leave it to run as long as a D-cell battry will take u. Place the motor in a cup and suspend it by tying wires around it. Those wires go over 2 bamboo skewers that rest on the top of the cup. Place a small piece of sponge over the skewers to prevent spillage.

Hope this helps.

Thanx!

[X34]

Thanks guys, what will happen if I just use the motor without running in, will that shorten its lifespan?

The reason I asked is actually not for running in but for powering a vessel underwater. I am contemplating whether to install the motor inside a watertight container (WTC) togther with ESC or outside it in a completely flooded compartment so that I dont have to direct water into WTC for cooling the motor. Looks like I better keep it inside WTC...

Loyn, r u keeping the twin motors of your fish outside WTC?

If u are running low voltage and low amp draw, not so critical la. Only car boys do all this stuff.

In the model sub, difficult to make WTC for motor, the stuffing box is below water line, if you seal it too well, the motor got to work extra hard to turn the prop. Motor compartment can expect it to be a little wet.

My 2 cents