Model Boat Mayhem

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: klz on October 21, 2015, 03:41:05 pm

Title: Any Ideas ? (Speed Controller)
Post by: klz on October 21, 2015, 03:41:05 pm
hi I purchased one of these

(http://www.hobbyking.com/hobbyking/store/catalog/68892.jpg)(http://www.hobbyking.com/hobbyking/store/catalog/68892.jog)

 it came with everything but Battery and TX & RX I put recommended battery in and after about 5 mins Speed controller was fried, On removing the speed controller I discovered it was a 50A watercooled controller so I purchased a 90A water cooled one this lasted about 12mins then stopped working, on investigation I found the speed controller to be so hot it was melting the waterproof sealent another speed controller fried. Today I tried again this time a 200A water cooled speed controller I managed to use this boat for about 30min with the odd battery change but the speed controller is still getting hot it is so hot you cannot touch it, does anyone have any ideas to what is going on? the battery is a 3cell 4000mah the motor and battery are cool to touch it just the speed controllers that seem to get hot.

Link to boat http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=68901 (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=68901)
Title: Re: Any Ideas ? (Speed Controller)
Post by: Stavros on October 21, 2015, 04:47:06 pm
Doesn't seem that the water is getting around the speed controller to cool it

Dave
Title: Re: Any Ideas ? (Speed Controller)
Post by: Shipmate60 on October 21, 2015, 04:49:43 pm
Did it come with the speed controller supplied?
If so contact the supplier.


Bob
Title: Re: Any Ideas ? (Speed Controller)
Post by: klz on October 21, 2015, 05:30:26 pm
hi Shipmate speed controller did come with the boat but its just to much trouble to sort out so I just brought new.
Title: Re: Any Ideas ? (Speed Controller)
Post by: klz on October 21, 2015, 05:33:20 pm
Hi Stavros water is travelling around but only when pushed at speed I will try and run a better cooling line, I could see water comming out the side but I never thought could it be enough.
Title: Re: Any Ideas ? (Speed Controller)
Post by: Martin (Admin) on October 21, 2015, 06:06:02 pm
 
Does the prop-shaft and motor turn freely?
Not fitted a bigger prop than supplied?
Using S3 batteries only?

Title: Re: Any Ideas ? (Speed Controller)
Post by: Netleyned on October 21, 2015, 06:21:11 pm
Is the esc in an enclosed box.
Even taking the lid off would help.
On a static test, hold the boat in water
and throttle forward and check you are getting
a good stream of water out of the starboard side hull fitting.
Looking at some photos the esc is first in line in the
cooling system.

Ned
Title: Re: Any Ideas ? (Speed Controller)
Post by: sparkey on October 21, 2015, 06:27:24 pm
 ;) I think Martin is on the right track,I would look at the power train motor,coupling,shaft and prop,something is binding there,strip the shaft down and check the backnuts have not tightened up on the shaft,see if the motor is running freely when disconnected from the shaft, no way should a 120amp ESC let alone a 200 amp ESC be getting hot with that motor.  also sounds to me that you don't have a fuse in circuit,always have a fuse in circuit fuses are cheaper than ESCs and can prevent the boat catching fire.....Ray. O0 O0 O0     
Title: Re: Any Ideas ? (Speed Controller)
Post by: essex2visuvesi on October 21, 2015, 06:57:46 pm
Looking at the reviews on HK website it seems you are not the only one with the issue
Title: Re: Any Ideas ? (Speed Controller)
Post by: Time Bandit on October 21, 2015, 08:09:24 pm
Dont believe it to be the drivetrain, the motor should get hot then too.
A 3660 dies pretty quickly if >100A run through it.

Also if we look at the batt capacity and run time (letīs just assume 33% average throttle) the motor draws not more than 4Ah/0,5h*3 --> 24A.
Should be a massive joke for a 200A ESC even if completely uncooled.

My guess is, that the ESC is running probably always in pwm mode and the FETīs never put through completely.
Try to teach it full throttle again, and push the stick only to 85% if you teach the ESC full throttle.
You should also check for the timing and set it too "low" or "very low".

Another issue might be long cables.
Shorten them as short as possible.
Title: Re: Any Ideas ? (Speed Controller)
Post by: klz on October 21, 2015, 08:45:16 pm
Thank you for all your answers I have a few things to try now, shaft and motor turn freely, Martin the boat is standard apart from the ESC. the ESC is not in a box the original one was but I have now mounted the ESC just behind the motor, the power leads could be classed as long so I will shorten them I will also try to improve the water flow.

Sparkey, the boat is not fused I don't know much about brushless and lipo's other than what I pick up or ask about.  One of the guys in the club who runs fast electrics said its pointless putting a fuse in line with something that can have a burst current of a 110a so none of my brushless have fuses my brushed boats do.