Davyx Posted October 18, 2006 Share Posted October 18, 2006 The Pan motor of one of my MH-660 is sometimes whistling when it's holding a position. The head is completely completely clean and I don't know what is the reason. Sometime the motor is very silent and suddenly it starts to whistle. Before starting to remove all inside to get this motor, I wanted to know if this annoying noise can disappear if I open the motor and try to clean it. Or do I have to change it completely? Link to comment Share on other sites More sharing options...
dbuckley Posted October 18, 2006 Share Posted October 18, 2006 I'd be surprised if it's the motor, it making a racket at standstill as its being told to do so by the driving electronics, surely...? Link to comment Share on other sites More sharing options...
lightsource Posted October 18, 2006 Share Posted October 18, 2006 I have an electric drill that whistles when the trigger (speed control) is only slightly depressed, but not enough current to turn the motor, as soon as the trigger is depressed far enough to turn the motor, the whistling stops. It may be that there is some current is 'leaking' from the drive electronics and therefore may not be a fault with the motor itself. Link to comment Share on other sites More sharing options...
Davyx Posted October 18, 2006 Author Share Posted October 18, 2006 I will look at the driver then. I will try to exchange it from another motor and see what is happening. Link to comment Share on other sites More sharing options...
reddude Posted October 18, 2006 Share Posted October 18, 2006 One of my moving heads also does this once in a while. It used to be the cooling fan but now it is the pan/tilt motors. Link to comment Share on other sites More sharing options...
saturnx21 Posted October 18, 2006 Share Posted October 18, 2006 dbuckley Posted Today, 12:01 PM I'd be surprised if it's the motor, it making a racket at standstill as its being told to do so by the driving electronics, surely...? Last time I checked driver chips don't make sounds!!! so dont waste your time there it deffinatly sounds like your stepper motor is in need of replacing! ;) Link to comment Share on other sites More sharing options...
nico_ah Posted October 18, 2006 Share Posted October 18, 2006 driver chip doesn't wishtle itself, but sure may tell the motor to do so ! Just because the setting of the electronic is not that correct ! Link to comment Share on other sites More sharing options...
Boggy Posted October 19, 2006 Share Posted October 19, 2006 I would check the motor.In theory, a driver can power one or more coils of a stationary stepper motor to increase the holding torque (i.e. the amount of force required to move the motor from its step). Also, by powering two coils at the same time the motor can be stopped between steps which allows the motor to be positioned more accurately. This may appear strange that you would power a motor to make it stand still but this is the case for stepper motors.I am not sure if this is used in practice or in your case but I figure it is worth knowing why the driver may be running for a stationary motor. Link to comment Share on other sites More sharing options...
Don Allen Posted October 19, 2006 Share Posted October 19, 2006 Substitution is probably the easiest way to see if it is the driver ic or the motor. Swap the pan and tilt motors over, then wait to hear which motor whistles. The whistling may be due to an intermittent driver ic that is "hunting" at the stop point, that is, driving the motor backwards and forwards through the stop point. This problem is usually overcome by having some hysteresis in the control system. What is going to be the difficult part here is hoping the whistling occurs when you are trying your substitution. I am assuming that the driver ic's are soldered in to the pcb which is normally done to reduce the cost of ic sockets and avoid the rick of the ic's creeping out of their sockets. If the driver ic's are in sockets then just change the whistling motor's driver ic. When troubleshooting try to only make one change at a time to help locate the fault. Swapping the motor leads over is making two changes, which probably can't be avoided if the ic's are soldered in place. Link to comment Share on other sites More sharing options...
JimWebber Posted October 19, 2006 Share Posted October 19, 2006 ...If the driver ic's are in sockets then just change the whistling motor's driver ic. When troubleshooting try to only make one change at a time to help locate the fault. Swapping the motor leads over is making two changes, which probably can't be avoided if the ic's are soldered in place. At the risk of instructing my Mother's Mother to suck the proverbial, if you are going to start playing with integrated circuits, don't forget to take anti static precautions... Fully agree with the substitution method of fault finding though!. Jim Link to comment Share on other sites More sharing options...
Davyx Posted October 19, 2006 Author Share Posted October 19, 2006 Yeah, the ICs are soldered on the pcb. I just swap the PAN and Tilt motors and the PAN motor is still doing this noise. So I will try to find a new motor and to replace it. I didn't think first to do this fast manipulation. :D Thanks all for your help anyway! Link to comment Share on other sites More sharing options...
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