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Can this motor run in water?

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rvk2

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Hi everyone, I'm building a toy boat for my nephew to play with in the pool....now I have a plastic boat, and I was just going to cut and attach an electric motor from a junk RC car to the boat. My question is, will an electric motor run if submerged in water, or does it need to be insulated? Or can I buy a special insulated motor? This motor will be powered by 2AA batteries. Just wanted to make sure I'm not making something that will zap the poor kid.
 
A regular motor from an RC car will not be designed to go in the water It will short out. It would have to be insulated, along with the batteries, switch, etc. Anything that carries electricity.
 
I don't think 3V from the battery will zap anyone.
I don't think water, even salt water would short out a 3V electric motor.
But when the motor gets wet it will corrode very badly. Then if the motor's wires don't short from the corrosion, the rusted shaft will sieze the motor's shaft and it will appear as a short to the battery, possibly making the motor or battery vey hot. :lol:
 
audioguru said:
I don't think 3V from the battery will zap anyone.
I don't think water, even salt water would short out a 3V electric motor.
But when the motor gets wet it will corrode very badly. Then if the motor's wires don't short from the corrosion, the rusted shaft will sieze the motor's shaft and it will appear as a short to the battery, possibly making the motor or battery vey hot. :lol:

How would it not short out audio? Being such a small motor, I'm sure that many of the contacts would be very close together, yielding a very small resistance in the water. Ive always thought of water as having a very small resistance :?
 
The Motor Will run Fine Under Water. Well For a Little while, till it Rusts and seizes up. Probably a Few Days.

zachtheterrible, Even though water has a Relatively Low Resistance Because of Impurities, It is Still a relatively High Resistance to a Very Low Voltge, such as 3 volts.
 
zachtheterrible, Even though water has a Relatively Low Resistance Because of Impurities, It is Still a relatively High Resistance to a Very Low Voltge, such as 3 volts.

So why bother making waterproof flashlights?
 
zachtheterrible said:
zachtheterrible, Even though water has a Relatively Low Resistance Because of Impurities, It is Still a relatively High Resistance to a Very Low Voltge, such as 3 volts.

So why bother making waterproof flashlights?

Because they will rust and rot away - what good is a flashlight you can only use once or twice?.

Water is EXTREMELY distructive to electronics and electrics - if it's only a 'one off' use (like on Scrapheap Challenge - or Junkyard Wars) it's not a problem running a motor under water, but don't expect it to last very long!.
 
so does anyone know if they make any water insulated motors? hopefully something small and cheap available at places like radioshack?
 
I don't think RadioShack exists anymore. I think they are an appliance store called "The Source- by CircuitCity" now. :cry:
 
insulating a motor to be submerged is difficult, you're probably better off having the motor above water level inside the boat, driving a metal shaft down at an angle through a tube, to the propeller... and put plenty of grease in the tube to keep it waterproof.
 
Water is EXTREMELY distructive to electronics and electrics


No.

I've spent a lot of years with Tektronix, probably the largest and finest manufacturer of oscilloscopes in the world. In the "old" days of 1960 through 1980, before modern scopes finally had little enough heat dissipation that they could be sealed in their cases, dirty scopes were usually washed -- literally WASHED -- with a solution of Kelite (a detergent) and water using a low-pressure venturi wand and a soft paint brush. The scope was then rinsed, given a blast of low-pressure air to blow out the majority of the water and then put into a low-temperature oven (around 150°F) for about two days to dry. No ill effects. Oh, and most of these instruments had fan motors, high-voltage transformers, rotary switches, toggle switches, connectors, vacuum tubes, ICs, transistors, sockets ... nearly every component imaginable.

Water isn't the problem. Contaminated water, seawater, prolonged exposure and a failure to thoroughly clean and dry waterlogged electronics is the problem. There are some components that are difficult to dry, however, such as those that will retain a fair amount of water in certain physical positions.

Dean
 
Dean Huster said:
There are some components that are difficult to dry, however, such as those that will retain a fair amount of water in certain physical positions.
Yeah Dean,
Like a little electric motor. :lol:
 
Dean Huster said:
Water is EXTREMELY distructive to electronics and electrics


No.

I've spent a lot of years with Tektronix, probably the largest and finest manufacturer of oscilloscopes in the world. In the "old" days of 1960 through 1980, before modern scopes finally had little enough heat dissipation that they could be sealed in their cases, dirty scopes were usually washed -- literally WASHED -- with a solution of Kelite (a detergent) and water using a low-pressure venturi wand and a soft paint brush. The scope was then rinsed, given a blast of low-pressure air to blow out the majority of the water and then put into a low-temperature oven (around 150°F) for about two days to dry. No ill effects. Oh, and most of these instruments had fan motors, high-voltage transformers, rotary switches, toggle switches, connectors, vacuum tubes, ICs, transistors, sockets ... nearly every component imaginable.

Water isn't the problem. Contaminated water, seawater, prolonged exposure and a failure to thoroughly clean and dry waterlogged electronics is the problem. There are some components that are difficult to dry, however, such as those that will retain a fair amount of water in certain physical positions.

There's rather a difference between using water to clean a product, blowing water off with an air blast, and then drying it in an oven - and running a motor under water!.

The cleaning is done in a VERY short time, and is dried before corrosion sets in - the motor will corrode in a very few days, although if you used distilled water it would reduce the corrosion a great deal.

I'll repeat again - WATER IS EXTREMELY DISTRUCTIVE TO ELECTRONICS AND ELECTRICS - always keep everything dry, and IF it does accidently get wet, dry it IMMEDIATELY, a hair dryer is quite good once you've removed any loose water.
 
Nigel Goodwin said:
There's rather a difference between using water to clean a product, blowing water off with an air blast, and then drying it in an oven - and running a motor under water!.

In the last place I worked, we have a motor that requires its casing internal and the rotor filled up with water for proper operation. We call that motor wet rotor. Works ok for years.
 
eblc1388 said:
Nigel Goodwin said:
There's rather a difference between using water to clean a product, blowing water off with an air blast, and then drying it in an oven - and running a motor under water!.

In the last place I worked, we have a motor that requires its casing internal and the rotor filled up with water for proper operation. We call that motor wet rotor. Works ok for years.

But it prolly used stainless steel bearings packed with grease, equally the slots were prolly potted to stop seapage into the stator winding.
It was prolly not a brushed machine and more likely a PM machine. The rotor prolly had a sleave over it to stop the magnets getting attacked by the water.

Yes you can have flooded machines (I work with some that are flooded with Skydrol) BUT they have to be propperly protected. Water (esp salt water) is one of the most corrosive substances there is
 
no, water is fairly destructive to electrics. We had a washing machine that leaked water from a crack in the 'tub' and well the motor hated it, it siezed up and killed a fuse in the switchbox.

meh: it was pretty old so it didn't matter about 15 years old !!!
 
Styx said:
But it prolly used stainless steel bearings packed with grease, equally the slots were prolly potted to stop seapage into the stator winding.
It was prolly not a brushed machine and more likely a PM machine. The rotor prolly had a sleave over it to stop the magnets getting attacked by the water.

It is an induction motor. Instead of using all sort of potting/sealing techniques to prevent water ingress into the slot and winding which is next to impossible, the designer choose to allow water to get to the winding. They use PVC insulation(bit like plastic wires) instead of enamal for the windings.
 
The easyest way to solve this wod be to have two floats and an motor betvean them (above water).Then have an long shaft on it that is under an angle so the end is in the water.On the end a propeler ufcurse.
 
well got the boat working, kid seems to be willing to take a bath now without crying on for hours....so overall a good solution, but it still intrigues me that I can't get my hands on a submersible motor. I swear I saw it once.....anyone have ideas on how to properly insulate a bldc motor? I have a project I'd like to try now.
 
rvk2 said:
but it still intrigues me that I can't get my hands on a submersible motor. I swear I saw it once.....anyone have ideas on how to properly insulate a bldc motor? I have a project I'd like to try now.

Well, I just read this thread, and am a little surprised no one has mentioned submersable pumps. I think they make them that even run off of solar power. I imagine the motor/ bearings are designed to resist water, and can be removed and used in such an application. Am I wrong?
 
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