What??!! H20 + ELEC
07-31-2003, 07:11 AM
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What??!! H20 + ELEC
I was reading the RC Universe Review of Accord II,
Running a elec. motor in water????? 
Elec + H20 don't mix, right?? I know it is DC and clean water, but still...??
I am new to RC plane, and the reviewer must know what he is doing. Can anyone enlighten me?
Also, what is the purpose of the diode on the motor lead?
Thanks
John
:stupid:
ELECTRICAL ASSEMBLY
At this time I decided that I would break in the motor to seat the brushes. To do this I attached a single AA cell to the motor terminals with alligator clips and let the motor run submerged in a cup of water for 10 minutes. While this step is not absolutely necessary, it will result in longer motor life and better performance.
At this time I decided that I would break in the motor to seat the brushes. To do this I attached a single AA cell to the motor terminals with alligator clips and let the motor run submerged in a cup of water for 10 minutes. While this step is not absolutely necessary, it will result in longer motor life and better performance.
Elec + H20 don't mix, right?? I know it is DC and clean water, but still...??
I am new to RC plane, and the reviewer must know what he is doing. Can anyone enlighten me?
Also, what is the purpose of the diode on the motor lead?
Thanks
John
:stupid:
07-31-2003, 10:32 AM
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What??!! H20 + ELEC
Contrary to popular belief, water is a poor conductor of electricity. That's not to say that water won't conduct electricity, because it will. However, electricity will only travel through water if there is no other choice.
In this case, there is a nice bundle of copper wires for the electricity to travel through. A tiny, tiny amount of electricity will still flow through the water, but nearly all of it will go through the motor, because the copper is the path of least resistance.
The diode on the end of the motor is called a Schottky diode, and it helps to "clamp" the voltage generated by the motor when it's freewheeling in the air. All motors turn into generators when the power is removed, and they continue to spin. This electricity would travel back into the ESC otherwise.
In this case, there is a nice bundle of copper wires for the electricity to travel through. A tiny, tiny amount of electricity will still flow through the water, but nearly all of it will go through the motor, because the copper is the path of least resistance.
The diode on the end of the motor is called a Schottky diode, and it helps to "clamp" the voltage generated by the motor when it's freewheeling in the air. All motors turn into generators when the power is removed, and they continue to spin. This electricity would travel back into the ESC otherwise.
08-01-2003, 07:51 PM
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What??!! H20 + ELEC
Thanks for your reply,
Would you please provide me a bit more detail on the installation of the Schottky diode? Cathode/Anode of the diode and +/- of the motor, which to which?
I understand pure H2O is a poor conductor, however the water flow inside the motor may wash away the lubricate. Also, moisture may trap inside and speed up oxidation in the bearing area. (I have only opened up a $5 rc motor, so I am not familiar with 'high-end' rc motor design at all)
Is this "submerge run-in" very popular in RC world??
Thanks
John
Would you please provide me a bit more detail on the installation of the Schottky diode? Cathode/Anode of the diode and +/- of the motor, which to which?
I understand pure H2O is a poor conductor, however the water flow inside the motor may wash away the lubricate. Also, moisture may trap inside and speed up oxidation in the bearing area. (I have only opened up a $5 rc motor, so I am not familiar with 'high-end' rc motor design at all)
Is this "submerge run-in" very popular in RC world??
Thanks
John
08-07-2003, 03:04 PM
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What??!! H20 + ELEC
John:
That's comon practice, breaking in a motor by running it submersed in water. When you remove it, allow it to run for a while and all the water will evaporate, then re-oil the bearings with a light oil. A better liquid to use is 99% pure alcohol. You cannot use this method of breaking in a motors where the shaft does not run all the way through the bearing, such as the IPS motor, since there is no way to oil the bearing.
It's also a great way to clean up a well run motor and you will be supprised at who much crud will come out.
I don't know the principal involved, but it does seem to speed up the process of breaking in the brushed. Once you have them formed to the shape of the commentator you see less sparking and a big improvement in preformance.
If your not sure on this, talk to Mark at B.C. Shaver.
fly SMALL, have a BALL:
That's comon practice, breaking in a motor by running it submersed in water. When you remove it, allow it to run for a while and all the water will evaporate, then re-oil the bearings with a light oil. A better liquid to use is 99% pure alcohol. You cannot use this method of breaking in a motors where the shaft does not run all the way through the bearing, such as the IPS motor, since there is no way to oil the bearing.
It's also a great way to clean up a well run motor and you will be supprised at who much crud will come out.
I don't know the principal involved, but it does seem to speed up the process of breaking in the brushed. Once you have them formed to the shape of the commentator you see less sparking and a big improvement in preformance.
If your not sure on this, talk to Mark at B.C. Shaver.
fly SMALL, have a BALL:
