gul532

Hi, everybody!

Recently I purchased a Wattage Cobalt 400 motor to replace a 400 can motor.
When I tried to break in the Cobalt motor according to the instruction it won't turn.
With a Multi DC Voltage adapter I started from 3v, 4.5v then 9v, still it doesn't turn, only I can hear some noise.

What's the problem? Is the motor faulty?
I can't turn the motor shaft with my fingers, it is very tight, only I can turn with pliers.

Please give me some advice.

Glen
Australia

VULTCH

The Cobalt 400 is very difficult to turn by the shaft. The magnets are very strong. Since the motor is open, the magnets can pull an object into the motor. Perhaps you have a small screw which has been pulled into it. Check it very closely. Put a prop on it and see it if spins freely by hand. If it does then it is ok. You said you converted an adapter to run it. This is probably your problem as this motor requires several amps to start and run. Try running it on two or 3 batteries sub C Ni-Cad,Ni-Mh, or "D" Alkaline without the prop. Even D Alkalines wont last long on this motor. I found a 7X5 prop to be the largest and best prop to run in Direct drive. I'm guessing your adapter cannot supply enough current to run it.

Tony

vicman

My Feedback: (10)

Hey Vultch, as you said it draws alot of amps. What batteries have you used on yours? The ones I have always scared me as they pull so hard.

VULTCH

I use Sanyo 1300CP NiCad, 7-8 cells. Also Max amps 4200Mah 7.4V Li-PO. Little monster will pull almost 20A WOT @ 7X5 APC prop.

vicman

My Feedback: (10)

Whenever I have messed with mine they sucked the life out of my car packs so hard and fast and hot, I just didn't feel like I could use them safely. What are your flight times, like 4-6 min?

VULTCH

At present the motor is not in any plane as I have went brushless in all my planes. I could run about 15 min with throttle management in a large glider ( Dynaflite Butterfly ) 4200mah Li-Po. But I replaced it with brushless also. The motor is too heavy for the power output as compared to brushless.

Vultch.

vicman

My Feedback: (10)

I am with you on the BL motors. I skipped right over the cobalt scene. Thanks for the info. They will stay right where they are.

gul532

Hi, Tony..

Thanks for your correct information. You are right. The problem was that the Multi volatage DC adapter does not supply enough current.
When I conected the 5v cable from the disused computer power supply to the Cobalt motor it began to turn!!
On the panel of the computer power supply it says 5v 20A, is it OK? Such high current doen not damage the motor in break-in?

If so, can I use this computer power supply to break in other Can motors without damage?
I am totally ignorant about the Electrics.

Thanks again, Tony!

Glen

VULTCH

The motor will only draw 2 or 3 amps or less at 5 volts without a prop so no harm will come. It would probably be better to have 3 volts but 5 is better than 6 or above. Just run the motor for a few minutes at a time until the brushes break in. If you see much sparking taking place at the brushes I would recommend using less voltage. Your break in time will be less at 5 volts than 3. On this motor I do not advise using the water method as it will remove the oil from the bearings. Break it in dry.
The amps drawn from the motor will be determined from the prop and voltage and the motor windings. You want to make sure the battery or power supply can supply enough current (Amps). The larger the prop the more current is required. The more voltage the more current. This is important in battery use as you will need a battery which will not be overloaded when the max current is required. If you use LiPo's for example you will need a pack capable of 20amps continuous with this motor or serious problems could occur ie. FIRE. Check the rating of the battery pack carefully. I hope you have a lot of fun with it.

Tony