Do 5303's make noise?

[Patriot]

I never noticed this before until today. As I picked up my bike for a no load test, I spun up the motor slowly. It spins up smoothly, and makes its soft growling sound as usual, but at about 90% full speed and throttle, it kind of shudders for a second, and has sort of a noisy rpm up/down spot. Almost like a rough spot towards full throttle. It doesn't stop spinning, it just kind of oscillates noisily at that point on the throttle. Once at full throttle, it's fine, and doesn't do anything except scream along like the monster it is.

I don't think it's a motor problem, I haven't had this happen before, and the motor is new.

Anybody notice this on theirs?

Could it be a throttle problem?

[pizark]

I have a 5303. I didn't think mine made noise (well... of course it makes "noise" but I think you know what I mean.) Anyways,... One day I tied my digicam to record some videos for friends,... and on playback... NOISE! Sounds almost like a banshee wail of a formula 1 car! Okay, not really... but definitely could hear high pitched winding sounds that I'd expect to hear from an electric motor. I guess the mic on the camera is better at picking up that frequency range.

by the way... what kind battery are you running it with? I have a 48v20a ping,.. and it just ain't cuttin' it. Actually, quite the opposite,... it keeps cutting out. Motor's darn amp happy.

pizark

[Ypedal]

You got a direct plugin CA on that controller ?

[steveo]

Hey

Unplug your c/a for a test .. see if it still does it..if its a new motor .. shouldn't be that .. .. could be a controller issue possibly

-steveo

[philf]

The kind of noise you describe most likely has more to do with the controlling logic (controller) than the motor itself. Nothing to be alarmed about, even if it is "displeasing" to hear. Anything that is throttled by PWM will likely resonate at certain frequencies. Think about cheap wall dimmers that scream/buzz at certain points in their operation... This is *sorta* like that, but with a few more layers...

[CGameProgrammer]

Why would the CycleAnalyst have anything to do with it?

[StevenR]

My 5303 makes noise but not like that. I have a whine/hum/growl that comes on at 25 MPH under load. It is quite pronounced and annoying - I like to run about 25 MPH and I always end up at 27 to get past the noise (never 23 - why is that?).

I have gotten a hesitation when my throttle connection gets loose but that is real pronounced and doesn't go away until you fix the connector.

[recumbent]

Anything that is throttled by PWM will likely resonate at certain frequencies...

Yeah, especially if your just holding it up in the air like you said without a load on it. However it would be interesting to know if another manufacture of controler would do the same thing, at the same RPM.

[Rassy]

Pizark wrote:

by the way... what kind battery are you running it with? I have a 48v20a ping,.. and it just ain't cuttin' it. Actually, quite the opposite,... it keeps cutting out. Motor's darn amp happy.

You can modify the BMS by adding a little solder to the (resistor?) bridge. The BMS's will vary, and some of them cut out under 35 amps. Before you modify the BMS you could determine what conditions cause it to cut out so that you can avoid extended stress on your battery after the modification.

[monster]

i have 2x 48v 12ah and it doesn't cut out unless one of the cells is low. maybe you should check your cell voltages to see if there is a weak cell.

[cerewa]

At anything near 100% of the no-load speed, pulse width modulation is normally not what limits the current to the motor, it's just I=V/R (current equals voltage divided by resistance) because the effective voltage is small (back EMF voltage being nearly as high as battery [forward] voltage).

Of course, since I don't know the resistance of your system it seems possible that you're still at your amperage limit when running full throttle, up until 90% of no load speed.