Motors not operating with the same force

propulsion

#1

I have an OpenROV 2.8

My starboard motor seems to be “sticker” than my port motor. Meaning my ROV likes to go in circles when driven forward.

When I try to turn the motors by hand the starboard motor seems to have more resistance than the port motor. I can flick the port motor and it spins some, but this does not happen with the starboard motor.

I had kind of notice it in my bathtub test that there was the tendency to turn in one direction – but I had put it down to not understanding the controls. When I put the ROV into open water, the tendency to turn was immediately apparent.

I couldn’t really tell on the resistance front (one motor not turning as easily by hand as the other) when I first checked, but having gone away for the holiday and come back, it now seems pretty obvious.

Is this likely a problem with the motor itself, or is there something that I might have tightened too much?

Thanks for your help


#2

One additional point of data – I looked at the motors in manual mode. And noted that when I ran the motors at 1… the port motor sounded very high pitch, whereas the starboard motor was at much more of a lower dull roar. I would presume that is another indicator something is not quite right, since I’d expect them to sound more or less the same (as a third data point the y-axis motor was also high pitched).


#3

I had a similar problem. It sounds like it could be a problem with one of the motors bearings. Try loosening the mount of the starboard motor a little bit and see if this makes any difference. Also, I would suggest contacting support http://www.openrov.com/support/ If it’s a faulty bearing or defective motor they might send you a free replacement.


#4

Thanks Brendan, will give that a whirl first.


#5

I have a similar issue. We have 2 rovs and the older one’s motors sound a lot more like the lower dull roar you described. I feel like if both motors bearing age as fast it’s not a problem.
If they don’t, then it might be a cause of a rov not keeping a staight line when going forward?


#6

So after working with support, and getting the latest software and firmware on board, the problem persisted. I bought some replacement motors though in case that did not work out – so I have since replaced the dull roaring starboard motor (for my fellow older gaming geeks out there: it sounded much like the pterodactyl in Joust).

The new motor – after a somewhat touch in go installation – is now in place and making the same high pitched sound as the other motor (or near enough anyway, not exactly the same).


#7

@acotter,
Sounds like you may have a bad ESC driving that motor?
Regards,
TCIII AVD


#8

Thanks. That is another thing that support had me update. But i don’t think that was it.

I assume that the ESC is not part of the engine itself. And since replacing the image, the new engine is working well, The problem seems to be in the old engine.

Cheers
Adrian