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Old Jan 25, 2013, 02:20 PM
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One more possibility that I found was that the connection between ESC and the corresponding motor is intermittent. The power cut on this motor would make the boat turn right. And I found out that this happens when there is more vibration. Now it make sense that at a higher speed, the boat turns right (pretty much clockwise circle).

The funny thing is that I used damn crimp on connector to connect the motor's bullet connectors to bare ESC wires. I will test this...

Does anyone know what is the size of the bullet connectors on "3660SL 3180kv Brushless Inrunner (WaterCooled)" in Boat Motors section?

Thank you for your time.

Kadem
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Old Jan 26, 2013, 08:41 AM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
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Quote:
Originally Posted by TheKaduu View Post
The weird part is that at the lowest speed the boat slightly turns to left. But at the next higher speed, boat does a hard clockwise circle... This was observed with props that rotates the same direction...Kadem
Hi Kadem,

Zozer explained that both motors may not rev up equally at low speed.

The clockwise spinning is a result of you using two props, spinning in the same direction, this creates propwalk, common with every single prop driven boat, and even worst on a two motor set-up.

If you want to remedy that, get counter rotating props.

Regards, Jan.
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Old Jan 26, 2013, 09:01 PM
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Pompebled: Thanks for the info. I got what he is saying, but i also found that right motor (looking at the boat from behind) is disconnecting from the ESC when the boat vibrates. I'll eliminate connection issue and try again.

I understand that no two ESCs or motors can br exactly the same. I also understand the propwalk issue. Again, I'll fix the connection issue first, then try it with the counter rotating props. Since I already installed the trims, I may be able to make the boat go straight.

On the other hand, no matter how bad the propwalk would be, 40" boat should not be making hard (3 feet diameter) clockwise circle UNLESS the motor on the right is not functioning (in my case the loss of connection to the right motor in high speed due to vibration.)
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Old Jan 31, 2013, 09:37 PM
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I got the female bullet connectors today. Both ESC are connected to the motors with a solid connection now. I am expecting the replacement charger from Venom tomorrow. I will test the setup over the weekend.
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Old Feb 01, 2013, 07:43 PM
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Good news and bad news... The good news is that the intermittent connection problem was the cause of my problem. After soldering the female bullet connectors, all i had to do was to adjust the homemade trim tabs... Everything work well! Thank you for your comments...

Now the bad news (at least for me). Since I control the ESCs from the microcontroller, I found out that if i treat the ESC as a servo and send it 95 degree, then motor starts turning at the lowest speed. I also found out that the speed does not increase beyond 130 degrees. And since I did not boat to go very fast, I just send 95 through 115 degrees with increment of 5 degrees to have 5 speeds. The boat went fine with speeds 1, 2... 3rd speed was a little rough!!! But i went ahead and tried the 5th speed like a moron... First couple seconds were find cause speed increases gradually (I programmed that way). At the 3rd second, boat gotten airborne, flipped 2 times and thankfully landed the right way. But the hatch contanng the GPS blew off during the flips. It took me 20 min to fish it out with the fishing pole. When i got the boat in my hand, i realized one of the shafts along with the prop was gone! The boat had some water in it too but luckily nothing was damaged. Now it is time to order a shaft and set of counter rotating props... IT NEVER ENDS!!!

Kadem
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